Roll Command Alerting System (RCAS) - Overview

RCAS. Roll Authority is displayed in amber warning the crew to a possible problem (Prosim737 avionics suite)

In October 2024 Prosim-TS incorporated RCAS into version 3.32b3 (beta) of their 737 avionics suite.  RCAS functionality can be enabled in the Instructor Operator Station (IOS) by placing a check mark (tick) beside the RCAS option.  By default RCAS is not enabled.

To enable RCAS in IOS:  settings/cockpit setup options/ac/rcas.

In this article, I will explain the functionality and various RCAS displays.

What is RCAS

RCAS is an acronym for the Roll Command Alerting System developed by Boeing, introduced as part of a Collins MCP update (P-9.0) to the Flight Control Computer (FCC).   RCAS is available as an optional equipment item in all late-model Next Generation 737 aircraft, along with other Boeing aircraft types (RCAS is standard equipment on the 737 MAX).

While RCAS shares some similarities with the Runway Awareness and Advisory System (RAAS) developed by Honeywell, they are distinct systems with different purposes.

The RCAS system is an alert mechanism designed to improve pilot awareness and control in certain autopilot and flight scenarios. It notifies the crew when the autopilot approaches the limit of its roll authority, allowing the crew to take corrective action, if necessary, to prevent situations like unintended bank angles.

RCAS consists of a Roll / Yaw asymmetry alert, Roll Authority alert and a Roll Command Arrow.

A condition is considered to exist when the autopilot reaches its roll authority limit due to the aircraft’s roll or yaw asymmetry not being optimal for the flight conditions.

Possible causes for a Roll Authority alert include:

• Fuel imbalance;

• Thrust asymmetry;

• Restricted movement of flight controls (jammed);

• Incorrect aircraft trim for flight conditions; and,

• A flap / slat asymmetry.

RCAS Displays and Aural Alerts

RCAS alerts are prominently displayed in amber, in the upper part of the Primary Flight Display (PFD).  Two written alerts can be displayed on the PFD:

1. Roll Authority; and,

2. Roll Yaw/Asymmetry.

Each alert is triggered by specific parameters. A Roll Authority alert activates when the autopilot authority reaches 100%, accompanied by an aural alert: “Roll Authority”.

A Roll/Yaw Asymmetry alert appears when the autopilot authority reaches or exceeds 75%; however, this alert does not trigger an aural warning.

Bank Pointer and Slip-skid Indication Bar Displays

RCAS displays indicators on the PFD when the aircraft reaches bank angles of 35 and 45 degrees.  Additionally, the bank pointer and slip-skid indication bar, depending upon the condition, are displayed in either solid or outlined amber or red. 

Important Point:

• Amber indicates that the alert is a caution, while red signifies an action that must be taken by the crew.

35 Degree Bank Angle

At a 35-degree left or right bank, an aural caution “Bank Angle” sounds. This aural warning is part of the EGPWS (Enhanced Ground Proximity Warning System).  Additionally, the white-coloured bank pointer changes to an outline in amber while the slip-skid indication bar changes to a solid amber.

45 Degree Bank Angle

When the aircraft reaches or exceeds a 45-degree bank, a red-outlined arrow appears, superimposed on the PFD to indicate the corrective turn direction. The bank pointer and the slip-skid indication bar turn solid red.  An aural command, either “Roll Right” or “Roll Left” is heard to guide the crew.

Accuracy of ProSim737

The colour scheme for the bank pointer and slip-skid indication bar do not match those of the real Boeing RCAS. In the real Boeing RCAS, when a 45+ degree over-bank situation occurs both the bank indicator and slip-skid indicator are displayed in solid red. ProSim737 only has the bank pointer in solid red, however, the slip-skid indicator bar is outlined in red. Furthermore, in a Roll Authority and or Roll / Yaw asymmetry condition, the bank pointer should be outlined in amber and the slip-skid indicator should be solid amber. In ProSim737, the bank pointer remains in outlined white, however, the slip-slid indicator is in outlined amber.

Unfortunately, the aircraft I have access to is not equipped with RCAS. The information concerning colours has been obtained from a Boeing information sheet.

This is but a small point. It must be remembered that RCAS has been released only into a beta release ( as at writing 3.32b10). I have little doubt that these shortfalls will be rectified in an update.

Final Call

 RCAS in summary,

1. Assists a flight crew to recover from high bank angle events;

2. Alerts the crew when autopilot saturation occurs;

3. Provides directional guidance when excessive bank angles are reached; and,

4. Issues a warning for asymmetry issues that may cause yaw-induced roll.

The RCAS is a valuable addition to the avionics suite, and it is hoped that other Boeing safety enhancements, such as the Runway Situation Awareness Tool (RSAT) and Loss of Control Mitigations (MCP), will be incorporated in the future.

Below: Gallery showing various RCAS displays. Each display should be self-explanatory (ProSim737 avionics suite).

View fullsize

View fullsize

View fullsize

View fullsize

Reverse Thrust Procedure

View fullsize

The reverse thrust levers are clearly visible in the first detent position.  OEM throttle quadrant converted for flight simulator use

Pilots tend to be numbers-orientated individuals.  They like concise instructions and do not like ambiguity.  Nor do they like being presented with something that is in ‘shades of grey’ rather than ‘black and white’. 

When, how, and for how long to deploy the reverse thrust (reversers) falls into the 'grey area'.

In this article, I will endeavour to unravel some of the uncertainties as to when and how to use reverse thrust.  I will also briefly discuss the relationship between the use of the autobrake and reverse thrust.

I am not going to delve deeply into every environmental consideration that needs to be analysed prior to the use of reverse thrust; this information is more than readily available from the Flight Crew Operations Manual (FCOM), Flight Crew Training Manual (FCTM) and other specific airline policy documentation.

Reverse Thrust Basics

Reverse thrust (reversers) is used only for ground operations and is used after touchdown to slow the aircraft;  it is used to reduce the stopping distance, minimise brake temperatures and decrease wear and tear.

Reverse thrust comprises four détentes and an interlock position, that are engaged by moving the thrust levers from the stowed down position through to the fully up position.  

1. No reverse thrust (thrust levers are closed / stowed position).

2. Detent 1 (idle reverse / thrust levers are at first position).

3. Detent 2 (thrust levers are at second position).

4. Full maximum reverse thrust (thrust levers are at fully upward position).

Between detent 1 and full maximum reverse thrust there is scope for the thrust levers to be positioned part way; thereby, altering the amount of thrust generated.

View fullsize

Schematic showing various positions for the thrust reverser levers

The interlock mechanism is felt when the reverse thrust levers are advanced to detent 1. The purpose of the interlock is to restrict movement of the reverse thrust lever until the reverser sleeves have approached the deployed position.

The procedure to use reverse thrust is very straightforward, however, questions arise as to whether to use detent 2 or full maximum reverse thrust, and when to begin reducing thrust and for how long.

Procedure

Following touchdown, without delay, move the reverse thrust levers to the interlock position and hold light pressure until the interlocks release (as the sleeves move rearwards).

For most landings, detent 1 and detent 2 will usually provide adequate reverse thrust (for normal operations).  If additional reverse thrust is needed (wet, slippery or short field landing), full maximum reverse thrust can be selected by raising the thrust levers past detent 2 to full maximum reverse thrust.  

To come out of reverse, the reverse thrust levers are returned to the detent 1 position, the engine allowed to spool down, and the levers then returned to the stow position.

Practically speaking, after touchdown maintain reverse thrust as required up to maximum thrust until the airspeed approaches 60 knots. Reverse thrust is then slowly reduced to detent 1 and then to reverse idle by taxi speed. Wait until the generated reverse thrust has bleed off, then slowly close the reversers and place them in the stow position.

Bringing the reverse thrust levers to detent 1 is important because it prevents engine exhaust re-ingestion and minimises the risk of foreign object debris (FOD) ingestion.  Idle thrust also bleeds off forward thrust from the engines.

The autobrake is disarmed when a safe stop of the aircraft is assured, or when the aircraft reaches taxi speed.

Important Point:

• If transitioning from using the autobrake to manual braking, use reverse thrust as required until reaching taxi speed and then disarm the autobrake.  

Disarming the autobrake before closing reverse thrust provides a relativity seamless transition which increases passenger comfort (there is no aircraft jolt).

Conditions Required To Engage Reverse Thrust

The reversers can be deployed when either of the following conditions occur:

1. The radio altimeter senses less than 10 feet altitude;

2. When the air/ground sensor is in ground mode; and,

3. When the forward thrust levers are in the idle position.

Until these conditions occur, the movement of the reverse thrust levers is mechanically restricted and the levers cannot be moved into the aft position.

It is important to always deploy reverse thrust as soon as possible following touchdown.  Do not wait for the nose wheel to touch down, but engage reverse thrust when the main wheels are on the runway.  Timely deployment will increase stopping power; thereby, increasing safety and reducing heat build-up in the brake system.  

A study determined that there was roughly a 17 second difference in stopping time when reverse thrust was deployed immediately the landing gear was on the runway as opposed to waiting several seconds for the nose gear to also be on the runway - reverse thrust is most effectual at high airspeeds and its effect decays on a linear scale as forward airspeed decreases.

Important Points:

• Reverse thrust should always be used with the autobrake, unless the runway is exceptionally long without a possibility of runway overrun (the reason for this will be explained shortly).

• When closing the reversers, always pause at detent 1.  Monitor the REV thrust output on the Primary Engine Display (center panel) and stow the reversers only after reverse thrust has dissipated.

Call-outs

The pilot monitoring usually makes the following call-outs:

• ‘60 knots’;

• ‘Reversers normal’ -  when both REV indications are green;

• ‘No reverser engine No: 1’ - if no REV indication or colour is amber; or,

• ‘No reverser engine No: 2’ -  if no REV indication or colour is amber; or,

• ‘No reversers’ -  if no REV indications or colour is amber.

NOTE:  Annunciators and displays are discussed later in the article.

During landing, the pilot monitoring (PM) should call out 60 knots to advise the pilot flying (PF) in scheduling the reduction of reverse thrust.  

When landings are in conditions that are suboptimal (heavy rain, snow, slush, etc), some operators stipulate that the PM operate and control the reverse thrust .  This enables the PF to concentrate solely on the landing roll out rather than having the extra responsibility of also controlling the reverse thrust.  

This said, although this procedure may lower pilot workload, it can cause problems when the PF is landing on a slippery runway or in marginal crosswind conditions.   At these times, the PF may wish to use the reverse thrust in conjunction with the brakes and there is little time to call out instructions to the PM.

Technical Aspects (basic operation)

Each engine on the Boeing 737 Next Generation is equipped with an hydraulically operated thrust reverser, consisting of left and right translating (moving) sleeves.  Aft movement of the reverser sleeves cause blocker doors to deflect fan discharge air forward, through fixed cascade vanes, producing reverse thrust.  

Hydraulic pressure for the operation of the thrust reversers comes from hydraulic systems A and B, respectively.  If hydraulic system A and/or B fails, alternate operation for the affected thrust reverser is available through the standby hydraulic system.  When the standby hydraulic system is used, the affected thrust reverser deploys and retracts at a slower rate and some thrust symmetry can be anticipated.

When reverse thrust is selected an electro-mechanical lock is released.  This causes the  isolation valve to open which results in the thrust reverser control valve moving to the deploy position, allowing hydraulic pressure to unlock and deploy the reverser system.

The system is designed in such a way that an interlock mechanism restricts movement of the reverse thrust lever until the reverser sleeves are in the deployed position.

Closing the thrust levers past detent 1 to the stow position initiates the command to stow the reverser.  When the lever reaches the full down position, the control valve moves to the stow position allowing hydraulic pressure to stow and lock the reverser sleeves.  After the thrust reverser is stowed, the isolation valve closes and the electro-mechanical lock engages.

Relationship with Flaps

There is an interesting relationship between the use of reverse thrust and flaps 40.

When the aircraft has flaps 40 extended, the drag is greater requiring a higher %N1 to maintain airspeed. This higher N1 takes longer to spool down when the thrust levers are brought to idle during the flare; this enables more energy to be initially transferred to reverse thrust.

Therefore, during a flaps 40 landing more energy is available to be directed to reverse thrust, as opposed to a flaps 30 landing.

Annunciators and Displays

Thrust reverse indicators are displayed in the Primary Engine Display located in the center panel slightly above the No: 1 and No: 2 %N1 indicators.  When reverse thrust is commanded, REV will be displayed initially in amber followed by green dependent upon the position of the thrust reverse levers.

• Amber:  Thrust reverser has been deployed from the stowed position and both sleeves have travelled ~10-90% to the deployed position.

• Green:  Thrust reverser has been deployed from the stowed position and both sleeves have travelled greater than 90% to the deployed position.

When either reverser sleeve moves from the stowed position, the amber REV indication annunciator, located on the upper display will illuminate.  As the thrust reverser reaches the deployed position, the REV indication illuminates green and the reverse thrust lever can be raised to detent 2.  

View fullsize

Electronic Engine Control (EEC) panel (AFT overhead). ProSim737 avionics suite virtual display

Additional reverse thrust annunciators are located on the aft overhead panel in the Electronic Engine Control (ECC) panel.  These annunciators are triggered by the retraction of the reverse thrust levers to the stow position.   

The annunciators will illuminate during a normal reverse thrust / stow operation for 10 seconds and then extinguish 10 seconds later when the isolation valve closes.  

A system malfunction has occurred if the reverser (REV) annunciator illuminates at any other time, or illuminates for more than approximately 12 seconds (in the later instance, the master caution and ENG system annunciator will also illuminate).

Possible reasons for a system malfunction are that the isolation valve, thrust reverser control valve, or one or both of the thrust reverser sleeves are not in their correct position.

Autobrake and Reverse Thrust Use (the grey area)

Both the autobrake and timely application of reverse thrust can be used to slow the aircraft, however, both come at a cost.  

Using the autobrake generates considerable heat in the braking system, translating to increased expenditure in maintenance and possible delays in turn around times (waiting for brakes to cool to operational temperature).  Conversely, reverse thrust consumes excess fuel.  Clearly there is a middle point where each will cancel out the other.

The immediate initiation of reverse thrust at main gear touchdown, and use of maximum reverse thrust, enable the autobrake system to reduce brake pressure to the minimum level – this is because the autobrake system senses deceleration and modulates brake pressure accordingly.  Therefore, the proper application of reverse thrust results in reduced braking and less heat generation for a large portion of the landing roll.

Based on this premise, it stands to reason that this is why Boeing recommend to use the autobrake in conjunction with reverse thrust.

Boeing states in the FCTM that: ‘After touchdown, with the thrust levers at idle, rapidly raise the reverse thrust levers up and aft to the interlock position, then to reverse thrust detent 2.  Conditions permitting, limit reverse thrust to detent 2’.

It appears to be Boeing’s intention to use reverse thrust as the major force to stop the aircraft, and as the use of maximum reverse thrust further minimises brake system heating, it would appear to be a preferred choice, despite the FCTM stating detent 2 is the preferred position for normal operations.

The official literature does not satisfactorily address this ‘grey area’   The result being that many 737 pilots use differing techniques when deploying and stowing the reversers.

Various Methods

If you observe how other pilots use the reversers, you will discover that there are several variations that follow the same theme.

1.    A pilot will, when the aircraft passes through 60 knots, close reverse thrust by lowering the reverse thrust levers through detent 1 to the stow position without stopping at detent 1;

2.    Try to locate detent 1 by ‘feel’ resulting in pushing the levers too far towards the stow position, causing forward thrust to unexpectedly occur momentarily;

3.    Deliberately close maximum reverse thrust at the 60 knots by placing the reverse thrust levers into the stow position.

In the above three scenarios, the reverse thrust levers have not been allowed to pause at  the detent 1 position.  Pausing at detent 1 is important as %N1 requires several seconds to reduce to idle thrust after maximum reverse thrust has been used, and it is during this ‘wind down’ period, as the reverse sleeves fully close, that %N1 will transition through 55-60%N1, which is forward thrust.  

By not allowing the reversers to pause momentarily at detent 1, to enable thrust to disparate below 55-60%N1, may cause the aircraft to momentarily accelerate.  This can be rather disconcerting, especially on a short field landing or landing in marginal conditions.

So What Do I do (normal procedure)

1. At touchdown I engage reverse thrust – either detent 2 or maximum reverse thrust (or part thereof).

2. Approaching 60 knots I slowly and smoothly retard the reverse thrust levers to detent 1.

3. I always allow a few seconds at detent 1 to enable %N1 to dissipate.

4.  Approaching taxi speed I disarm the speedbrake and close the reversers.

• At no time do, unless in an emergency, do I close the reversers suddenly; I always close the reversers smoothly and slowly. This enables %N1 to dissipate gradually.

Final Call

The procedure to deploy reverse thrust is straightforward and very easy to accomplish, and there is little argument that reverse thrust should be used on all, but the longest runways in optimal environmental conditions.   However, there is confusion and often disagreement to when the reversers are deployed, whether maximum reverse thrust should be used, and for how long the reversers should be left in the open position before retraction and stowing.

It is unfortunate that the information written in the Flight Crew Training Manual (FCTM) and Flight Crew Operations Manual (FCOM) does not provide a more objective ‘black and white’ answer to this procedural dilemma.

Video

The below video shows the REV indicators on the Primary Engine Display (when reverse thrust is commanded) and the REVERSE annunciators on the ECC panel (AFT overhead).  Video taken directly from ProSim-AR 737 avionics suite (virtual software).  Video upload to U-Tube rather than VIMEO).

Integrated Approach Navigation (IAN) - Review and Procedures

View fullsize

Japanese airlines nearly always gravitate to new technology.  ANA landing RJAA (Narita, Japan). Maarten Visser from Capelle aan den IJssel, Nederland, JA02AN B737 ANA gold cs landing (7211516992), CC BY-SA 2.0

Increased navigational accuracy obtained from software and hardware improvements have led to several enhanced approach types being developed for the Boeing 737.  These augmented approach types provide a constant rate of descent, follow an approximate 3 degree glide path, and eliminate the traditional step-down style of approach.   

This improves landing capability in adverse weather conditions, in areas of difficult terrain, and on existing difficult to fly approach paths.  Not to mention, the benefits that a stabilized and safer approach bring: greater passenger comfort, less engine wear and tear, and lower fuel usage while bringing less workload for the flight crew. 

In this article, I will discuss the concept of Integrated Approach Navigation (IAN) and explain the procedures recommended by Boeing to successfully implement IAN. 

The Boeing Flight Crew Training Manual (FCTM) has an excellent section addressing IAN, and I recommend you read it to gain a greater understanding of how the IAN system functions.

The Navigation Performance Scales (NPS), which augment IAN, will not be discussed.  NPS will form part of a future article.  Information in this article relates to FMC software U10.8A.

Overview

Integrated Approach Navigation (IAN) derives information from an approach type selected from the Flight Management Computer (FMC) database to generate a 3 degree glide path from the Final Approach Fix to the threshold of the runway.  In so doing, it displays visual cues similar to the Instrument Landing System (ILS).  Flight path guidance is derived from the FMC, navigational radios, or combination of both. 

To use IAN, an approach with a glide path must be selected from the FMC database.  The approach must include a series of waypoints that depict a vertical profile that includes a glide path.  

An IAN approach may be flown with a single autopilot, raw data, or by following the visual cues displayed on the Flight Director (FD).

IAN is an airline option, and although not every airline carrier will have IAN as part of their avionics suite, the technology is becoming more popular as the safety and economic benefits of IAN are understood by airline carriers.

Geometric Path (Glide Path)

An IAN Approach approximates a 3 degree glide path (descent profile) from the Final Approach Fix (FAF) to approximately 50 feet above the runway threshold.  Although, the glide path may not comply with altitude constraints in the FMC prior to the FAF, the generated glide path will always be at or above the altitude constraints between the FAF and the Missed Approach Point (MAP) displayed in the FMC.

Critically, an IAN approach is a Category I Non Precision Approach (NPA) and is not to be confused with an ILS Precision Approach.  Therefore, NPA procedures must be adhered to when initiating an approach using IAN.  

Although the automation provided by IAN will guide an aircraft (in most cases) to the threshold of the runway, IAN has not been designed to do this.  Rather, IAN has been designed to guide the aircraft to the MAP published on the approach chart.  The flight crew will then disengage IAN by disengaging the autopilot and autothrottle and fly the remainder of the approach manually as per NPA protocols.

In some instances, the final approach course (FAC) is offset from the runway center line and manoeuvring the aircraft for direct alignment will be necessary, whilst following the glide path angle.

Although the final approach is very similar to an ILS approach, IAN does not support autoland; if the aircraft is not in a stable configuration and you are not visual with the runway at or beyond the MDA, a missed approach procedure (Go-Around) should be executed.

Consistency in Procedures (eighteen approach types to one)

The introduction of IAN has condensed the number of approach types (and differing procedures) to one consistent procedure; minimising the amount of time an airline needs to train pilots in numerous approach types.  Time is money and utilising advanced technology such as IAN can increase airline productivity and safety.

Approach Types

IAN can be used for the following approach types:

• RNAV

• RNAV (RNP) – (provided there are no radius to fix legs)

• NDB and VOR

• GPS & GNSS

• LOC, LOC-BC, TACAN, LDA SDF (or similar style approaches)

Note that if using IAN to execute a Back Course Localiser approach (B/C LOC), the inbound front course must be set in the MCP course window.

During the approach you must monitor raw data and cross check against other navigational cues.  Furthermore, although the use of IAN is recommended only for straight-in approaches, line use suggests that flight crews routinely engage IAN up to, but not exceeding 45 degrees from the runway approach course.

IAN is compatible with several approach types, however, being compatible does not necessarily mean that every approach type in the FMC is suitable. 

Since IAN was introduced, additional approaches have been developed and added to the RNAV family; in particular, RNAV (RNP) approaches, that use ‘radius to fix’ (RF) to generate a curved path that terminates at a location where an approach procedure begins.   These approaches have been designed to optimise airspace and usually have tight separation requirements; to fly these approaches an aircraft is required to have additional on-board navigation performance monitoring and alerting equipment. 

These approach charts are identified by the title RNAV (RNP) RWY XX and the letters AR (Authorisation Required) in the description of the chart. 

These approaches and are not suitable to use with IAN; they should be flown with LNAV/VNAV.

Recommended Approach Types

The best approach to use with IAN are straight-in or near straight-in approaches.  VOR, LOC, NDB, RNAV and RNAV (GNSS) approaches work especially well as these approaches usually provide relatively long straight-in legs. 

IAN can be used on an RNP (AR) approaches as long as there are no RF turns involved (straight-in approach only).  If flying such an approach you should be aware that the legs can be quite short and IAN may arm and engage quite late in the approach profile.

Important Point:

•    The use of IAN is not authorised for a RNAV (RNP-AR) approach.

Using IAN – General

IAN does not need to be specifically ‘turned on’ for it to function; the functionality, if installed in the aircraft, is always operational.  When the aircraft is within range of the designated approach, the runway data and/or Deviation Pointers will annunciate and be displayed on the PFD.  At any time after this point has been reached, IAN can be armed and or engaged by pressing the APP button on the MCP.

Navigation Radios and Radio Frequencies

For an IAN approach to function, an approach procedure with a glide path must be selected from the FMC database.  Although selection of navigation radios is not mandatory, selection is recommended, as correct tuning of the radios can provide increased visual awareness and redundancy, should a CDU failure occur, or there be a corruption of the data in the FMC. 

Boeing strongly advise to tune the radios to the correct localiser frequency for the approach.  This eliminates the possibility of the radio picking-up another approach from a nearby airport (and providing erroneous data to the crew).  The ILS frequency must never be used with an IAN approach (unless the glideslope is inoperative).  In the case of an inoperative glideslope, the G/S prompt in the CDU must be selected to OFF to ensure that the FMC generated glide path is flown. 

Minimum Descent Altitude (MDA)

As mentioned, an IAN approach is a NPA, and when authorised by the Regulatory Authority non-ILS approaches can be flown to a published VNAV Decision Altitude/Height (DA/H) or to a published MDA (the MDA is used as a decision altitude).  If not authorised to use the MDA as a decision altitude, crews must use the MDA specified for the approach flown.

To comply with the MDA protocols during a constant angle approach where a level off is not planned at the MDA, it is necessary to add +50 feet to the published MDA.  This enables an adequate buffer to prevent incursion below the MDA and adhere to the NPA protocols.

Important Points:

• IAN uses the FMC database to generate a 3 degree glide path from the FAF to the runway threshold.  IAN does not require the navigation radios to be tuned.  However, it is recommended to tune the radios.

• Some approaches in the FMC database have a number of glide paths displayed with differing altitudes.  When presented with this scenario, always select the first glide path and altitude.

View fullsize

IAN approach to RJAA ILS X or LOC X Rwy 16L.  The localiser has been captured and the FMA displays FAC in green, while G/P is armed (FMA G/P white).  The vertical Deviation Pointer is displayed as an outlined magenta-coloured diamond (anticipation pointer) while the localiser is displayed as solid magenta (because FAC has been captured).  The source of the runway data is from the FMC (ProSim737 avionics suite)

Using IAN - IAN Annunciations and Displays

IAN can display several visual cues to alert you to the status of the IAN system.  The cues are triggered at various flight phases and are displayed on the attitude display of the Primary Flight Display (PFD) and on the Flight Mode Annunciator (FMA).

Runway Data:   Runway data (runway identifier, approach front course, approach type and distance to threshold) is displayed in the top left area on the PFD when either the localiser or the selected FMC approach is in range of the runway. 

View fullsize

IAN approach to RJAA ILS X or LOC X Rwy 16L.  The localiser and glide path have been captured.  The FMA displays FAC and G/P in green and SINGLE CH is displayed.  The Deviation Pointers, previously in outline (Figure above), are now solid filled.  The aircraft will descent on the glide path to the threshold of the runway (ProSim737 avionics suite)

If the source of the runway data is the navigation radio, then this information will be displayed when the radio is in range of the localiser.  However, if the primary data source is from the FMC (radio not tuned) the runway data will be displayed only after IAN has engaged.   When IAN engages, the runway data will be sourced from the FMC.  This will be evident as the  approach type will be displayed on the PFD.

The approach type (LNAV, FMC, LOC, ILS etc) displayed will depend on what type of approach has been selected from the FMC database. 

Approach Guidance:  Approach guidance (Deviation Pointers) are displayed on the PFD whenever IAN is in range of the runway.  When the Deviation Pointers are displayed, IAN can be used.

Final Approach Course (FAC):  The letters FAC are displayed on the center FMA when IAN is armed.

It stands to reason, that FAC (lateral guidance) usually annunciates prior to G/P (vertical guidance), but depending on the position of the aircraft when APP in pressed, both annunciations may be displayed at the same time.

Glide Path (G/P):  The letters G/P are displayed on the right FMA when IAN is armed.

FMA FAC and G/P Colours:  Two FMA colours are used.  White indicates that the FAC or G/P is armed.  The colour of the FMA display will change from white to green when the aircraft captures either the localiser or glide path. 

Mode Control Panel (MCP):  Arming IAN (pressing the APP button on the MCP) will cause the letters APP on the MCP to be illuminated in green.  The APP light will extinguish when IAN captures the glide path.  

Lateral and Vertical Guidance Deviation Pointers:  Deviation Pointers display the lateral and vertical position of the aircraft relative to the final approach course of the selected runway.  The lateral pointer represents the localiser while the vertical pointer represents the glide path.  The pointers are displayed whenever IAN is in range of the runway. 

The pointers will initially be displayed as either magenta or white-coloured outlined diamonds.  When the aircraft captures either the localiser or glide path, (2 1/2 dots from center) the pointer (s) will change from an outline, to a solid-filed magenta-coloured diamond.

Whether the initial colour of the diamonds is magenta or white depends on which pitch/roll mode has been selected when the aircraft comes into range.

Although the correct name for the pointers is Deviation Pointers, they are often called anticipation pointers, anticipation cues or ghost pointers (ghost pointers being an 'Americanism').

During an IAN approach:

1. The deviation alerting system will self-test when passing through 1500 feet radio altitude.  The self-test will generate a two-second FAC deviation alerting display on each PFD (the pointers will flash in amber); and,

2. If the autopilot is engaged, and at low radio altitudes, the scale and Deviation Pointers will turn amber and begin to flash if the deviation from either the localiser or glide path is excessive.

SINGLE CH:  SINGLE CH will be displayed in green, when the aircraft captures the glide path (both the localiser and glide path). At this time, the Deviation Pointers will change from white-coloured outlines to solid magenta-coloured diamonds.  FAC and G/P on the FMA will also be in green.  Additionally, the illuminated APP button on the MCP will extinguish.  At this point, the aircraft will be guided automatically along the glide path.

Flight Mode Annunciations (FMA):  The FMA display will vary depending on the source of the navigation guidance used for the approach.

For localiser-based approaches (LOC, LDS, SDF and ILS (glideslope OUT), the FMA will display VOR/LOC and G/P.  For B/C LOC approaches, the FMA will display B/CRS and G/P.

If lateral course guidance is derived from the FMC (RNAV, GPS, VOR, NDB and TACAN approaches), the FMA will display FAC and G/P.

Ground Proximity Warning System (GWPS) Aural Warnings and Displays:  GWPS warnings will annunciate if at any time the aircraft deviates below the glide path, and failure to disengage IAN at the appropriate altitude will trigger a GPWS aural warning alert ‘autopilot autopilot’ at 100 feet radio altitude.  This is in addition, to the words ‘autopilot’ being displayed on the PFD.

Using IAN – At What Distance Does IAN Work

IAN is not designed to navigate to the airport and its functionality will only be available when the  aircraft is in range of the airport runway; for a straight-in approach, this is at approximately 20 nautical miles.  However, this distance can be considerably less if the aircraft is not on a straight-in course to the runway. 

Important Point:

• To give you the longest time from which to transition to an IAN approach, try to choose a suitable approach type (from the FMC) that exhibits a ‘more or less’ straight-in approach.

Using IAN – When to Arm and Engage IAN

1. IAN can be armed at anytime after the Deviation Pointers are displayed on the PFD.  

2. To arm/select IAN, the flight crew press the APP button on the Mode Control Panel (MCP) similar to performing an ILS approach.

3. IAN is armed only after clearance for final approach has been received from Air Traffic Control (ATC).  By this time, the aircraft is probably on a straight-in approach.

4. IAN cannot be used for STARS and is not designed to be engaged when the aircraft is ‘miles’ from the designated runway.  Transition to an IAN approach can be from any of several pitch/roll modes.

5. IAN (if armed) engages automatically when the either the localiser or glide path is captured.

IAN should only be armed or engaged when:

1. The guidance to be used for the final approach is tuned and identified on the navigation radio;

2. An approach has been selected from the FMC database that has a 3 degree glide path;

3. The appropriate runway heading is set in the course window in the MCP;

4. The aircraft is on an inbound intercept heading;

5. ATC clearance for the approach has been received; and,

6. The approach guidance information is displayed on the PFD along with the lateral and vertical Deviation Pointers.

Disengaging IAN

IAN is either armed, engaged or not engaged. 

If you want to disarm IAN from the arm mode, it is a matter of pressing the APP button on the MCP; the light on the APP button will extinguish and the Deviation Pointers on the PFD will not be visible.

If you want to disengage IAN after it has captured either the localiser or glide path (or both), pressing the APP button on the MCP will do nothing.  In this scenario, to disengage IAN you will need to conduct a Go-Around by selecting TOGA, or change the pitch/roll mode (i.e. Level Change).

Disconnecting the autopilot and flying manually will also disengage IAN; the upside being that the Deviation Pointers will remain displayed on the PFD, until a different pitch/roll mode is selected.

Important Points:

• If the navigation radio is not tuned to the localiser, the runway data will not be displayed until IAN is engaged, however, the Deviation Pointers will be displayed.

• IAN can be armed whenever the aircraft is in range of the runway - in other words whenever the Deviation Pointers are displayed on the PFD.

• When IAN is armed, the FAC and G/P display on the FMA is coloured white.

• When IAN is engaged (localiser or glide path) the FAC and G/P on the FMA is coloured green.

• IAN will only engage after capture of either the lateral (FAC) or vertical glide path (G/P).

• When IAN has captured the glide path, SINGLE CH will be displayed in green in the PFD.

Using IAN - Set-Up and Procedure

The following procedures used for an IAN approach are derived from ILS procedures and are consistent for all approach types. 

• Select the appropriate approach to use from the FMC database.  Ensure that the selected approach has a glide path.  Do not alter any of the approach constraints. 

• Set the altitude of the glide path (from the FMC) in the MCP altitude window.

• Fly the aircraft in whatever pitch/roll mode to the Initial Approach Fix (IAF).  Remember straight-in approaches are best, although offsets between 25 and 45 degrees may be used but not recommended. 

• Configure the navigation radios to the correct frequency based on the approach type you have selected from the FMC database.  Do not use an ILS frequency.

• Set the barometric minimums to the altitude published on the approach chart.  Add 50 feet to avoid breaking NPA protocols.

• Set the correct runway approach course in the MCP course window.

• Do not select IAN (press the APP button) until the aircraft is in the correct position relative to the approach course. 

• When approximately 2 miles from the FAF - GEAR DOWN, FLAPS 15, SPEED CHECK.

• At glide path capture (FAF) – FLAPS 25/30 (landing flaps), SPEED CHECK.

• At 300 Feet below glide path capture, reset the MCP altitude window to the missed approach altitude.  Failure to wait until the aircraft descends 300 feet will cause the ALT HOLD annunciation to display and the aircraft levelling off.

• At minima – Disengage autopilot and autothrottle, manually align aircraft to the runway, and follow the Deviation Pointers and Flight Director (FD) cues to the runway threshold.   Maintain the glide path to the flare and do not descend below the displayed glide path. 

Although glide path guidance can be used as a reference once the aircraft descends below the MDA, the primary means of approach guidance is visual.  If not visual at the MDA, execute a Go-Around.  Remember, using IAN is a NPA.

Important Points:

• When using IAN the aircraft should be configured approximately 2 nautical miles from the FAF (this is one of the fundamental differences between an IAN approach and an ILS approach).

• Often, the runway may not be aligned with the FMC generated course.  The FCTM states; ‘If the final approach course is offset from the runway centreline, manoeuvring to align with the runway centreline is required.  When suitable visual reference is established, continue following the glide path angle while manoeuvring to align with the runway.

• Flying an IAN approach is an NPA; it is important to fly visually after passing the MDA.

• The approach mode (APP on center CTR knob) on the EFIS can be selected when using IAN.  This will display the IAN approach on the Navigation Display as if it is an ILS approach.

Transitioning to an IAN Approach

A flight crew will usually transition to an IAN approach 2 nautical miles prior to the Initial Approach Fix (IAF).  

At this distance from the runway there is not a lot of time to configure the aircraft for landing, and if IAN engages when the aircraft is either above or below the glide path, there is a possibility that the aircraft will abruptly and unexpectedly ascend or descend as the automation attempts to capture the glide path.   Therefore, you must be in diligent that the aircraft’s altitude roughly matches the position of the Deviation Pointers when close to the FAF.

Techniques to Transition Smoothly to an IAN Approach

There are several techniques that can be used to ensure a smooth transition to an IAN approach.

By far the easiest technique to ensure a seamless transition without any abrupt lateral or vertical deviation, is to position the aircraft ‘more or less’ within one dot deviation of the localiser or glide path (Deviation Pointers) prior to selecting IAN. 

In this way you can follow (‘fly’) the Deviation Pointers and engage IAN when the aircraft is more or less aligned with the position of the pointers (similar to how an ILS approach is carried out).

Another technique, is to fly the aircraft until ALT HOLD is displayed in the FMA (assuming that the altitude set in the altitude window in the MCP is approximately 2 nautical miles from the FAF).  Then select IAN.  This should enable the aircraft to smoothly capture the glide path when reaching the FAF.

Importantly, if transitioning to IAN from VNAV, it is prudent to engage SPD INTV to manually control MCP speed.

View fullsize

FIGURE 1:  Visual representation of an IAN approach and transition from roll mode. (Copyright Boeing FCTM).

Increased Spatial Awareness

Any approach can be busy and it is easy to forget something.  Therefore, it is wize to create a circle at 2 miles from the FAF that can be displayed on the Navigation Display (NP).

One way to accomplish this is by using the FIX page in the CDU. 

In the LEGS page copy to the scratchpad the FAF (click the line on which the FAF is located).   Open the FIX page and upload the FAF (from the scratchpad) to the FIX entry.  To create a dashed circle at 2 nautical miles from the FAF, enter /2 to Line Select Left 1.

Important Points:

• Maintaining the correct approach speed and altitude is paramount to a successful IAN approach.  If the aircraft is travelling too fast, slowing down after IAN has engaged can be difficult.  Likewise, if the aircraft is too high and IAN engages, the vertical descent can be steep as the aircraft attempts to follow the FMC generated glide path.

• You must be vigilant and anticipate actions and events before they occur.

Using IAN - Situations To Be Attentive Of

Automation can have its pitfalls and IAN is no different.  However, once potential shortcomings are known, it is straightforward to bypass them.  The most common mistake, especially with virtual pilots, is not following the correct procedure.

Possible 'surprises' associated with an IAN approach are:

1.   Failing to configure the aircraft prior to IAN engaging in FAC and G/P mode.

Unlike an ILS approach, where configuration for landing is initiated when the aircraft captures the glideslope (usually some distance from the runway) during an IAN approach configuration for landing is initiated approximately 2 nautical miles from the FAF.  

If you have not configured the aircraft for landing prior to the capture of the glide path, there may be insufficient time for you to complete recommended actions and checklists.   

If you believe this will occur, there is no reason why configuration cannot occur at an earlier stage.

2.   Forgetting to set the Missed Approach Altitude (MAA) in the MCP.

Failing to wait until the aircraft has descended 300 feet below the glide path capture altitude to reset the MCP altitude to the MAA.  Failure will cause the ALT HOLD annunciation to display and the aircraft leveling off.

3.   Approaching the runway while not on the correct intercept course.

IAN operates flawlessly with straight-in approaches and to a certain extent with approaches up to 45 degrees from the main approach course, however, IAN will not engage if you approach the assigned runway at 90 degrees.  Nor will IAN engage if you are attempting to fly a STAR.

4.   Forgetting to set the initial glide path altitude in the MCP (from the FMC).

A common mistake is not setting the glide path altitude (from the FMC) in the MCP window when configuring the aircraft for an IAN approach.

ProSim737 and IAN

Installing IAN to ProSim-AR Avionics Suite

IAN forms part of the avionics suite, however, for IAN to function it needs to be selected (turned on) in the ProSim-AR IOS (Instructor Operator Station).  The same is for the Navigation Scales (if required).

To turn on IAN, open IOS: Settings/Cockpit Setup Options/Options and place a tick in the appropriate box beside IAN.  A restart of the ProSim-AR main module may be required for the change to take effect.

IAN was introduced to the ProSim737 avionics suite in December 2014.   For the most part, the functionality is reliable and operates as it should (see note 1).

As at writing, known issues are as follows (this may change with Version 3 software updates):

• ProSim737 does not display the IAN runway data immediately following the engagement of TO/GA during the take-off roll. 

This is incorrect.  In the real aircraft, this information is displayed immediately following the engagement of TO/GA during the take-off roll while.  (further research required)

• The colour of the approach guidance display (LNAV/VNAV) after TO/GA is engaged is currently white.  This is incorrect.  The colour should be green.

• At 100 feet AGL, if IAN is engaged and the autopilot remains selected, a flashing AUTOPILOT warning in amber colour will be displayed on the PFD.   This is correct.  However, an audible ‘autopilot’ callout should also be heard.  This is not simulated.

Important Point:

• ProSim737 users should also note, that for IAN to function within the avionics suite, it must be selected in the cockpit set-up page of the Instructor Station (IOS).

Note 1:   IAN works flawlessly for straight-in approaches (or approaches that are slightly offset).  However, the ProSim software when using some RNAV (RNP) approaches has trouble maintaining the correct vertical profile.

When a RNAV (RNP) approach (not AR) is selected, IAN arms and engages very late in the approach profile (after the FAF).  The altitude that IAN engages is well below the profile used in VNAV; this results in the aircraft diving to capture the IAN glide path.  Once the aircraft is established on the glide path IAN works as it is supposed to. 

The above scenario does not occur with every VNAV (RNP) approach; only those that exhibit a curved radius to fix (RF) profile or short leg profile to the runway threshold.

In the real aircraft (depending on operator and country of operation) IAN can handle all RNAV (RNP) approaches with the exception of RNAV (RNP-AR)  approaches.

In comparison, Precision Manuals Development Team (PMDG) NGX and NGXu can fly the above approaches in IAN.  This has been achieved by artificially replicating the approach using various hidden ‘waypoints’ that their software can read.  In effect, what you are seeing is the aircraft flying over the waypoints that have been overlaid onto the curves in the approach. 

I do not believe ProSim has replicated PMDG’s methodology in their software.

Therefore, if flying an RNAV (RNP) approach using IAN, select only those approaches that are ‘more or less’ straight-in without RF curves or turns; otherwise, use LNAV/VNAV.

BELOW:   Montage of four screen captures of the PFD showing some of the displays generated during an IAN approach (images upper left to right then bottom left to right).  Images 1-3 are sequential. Image 4 is standalone.

Image 1:  Aircraft is LNAV/VNAV approaching the IAF.  The aircraft is too far from the runway for IAN to be in range to operate (RJAA VOR Rwy 16R).

Image 2:  Aircraft is in range of RJAA localiser (tuned in the navigation radio).  Runway data is displayed from localiser and Deviation Pointers are displayed in outlined white-coloured diamonds (anticipation pointers).  The Deviation Pointers will change from white (outline) to magenta (either outline or solid) when either the localiser or glide path is captured.  FAC and G/P are displayed on the FMA in white indicating that IAN has been armed.  Note that if IAN was not armed, only the runway data and Deviation Pointers would be displayed (RJAA VOR Rwy 16R).

Image 3:  IAN has captured the localiser and the lateral Deviation Pointer is displayed as a solid magenta-coloured diamond.  FAC (in green) is displayed on the FMA.  The vertical Deviation Pointer is still in outline and in white (anticipation pointer), as is the G/P on the FMA.   IAN is tracking the localiser (RJAA VOR Rwy 16R).

Image 4:  IAN has engaged.  The runway data is now sourced from the FMC and not the localiser (as in the above examples).  The FMA displays FAC and G/P in green colour, SINGLE CH is displayed, and both Deviation Pointers are solid magenta-coloured diamonds.  IAN has captured the Glide Path (RJAA ILS X or LOC X Rwy 16L).

View fullsize

Montage of four screen captures of the PFD showing some of the displays generated during an IAN approach (images upper left to right then bottom left to right).  Images 1-3 are sequential. image 4 is standalone

Image 1: Aircraft is LNAV/VNAV approaching the IAF.  The aircraft is too far from the runway for IAN to be in range to operate (RJAA VOR Rwy 16R).

Image 2: Aircraft is in range of RJAA localiser (tuned in the navigation radio).  Runway data is displayed from localiser and Deviation Pointers are displayed in outlined white-coloured diamonds (anticipation pointers).  The Deviation Pointers will change from white (outline) to magenta (either outline or solid) when either the localiser or glide path is captured.  FAC and G/P are displayed on the FMA in white indicating that IAN has been armed.  Note that if IAN was not armed, only the runway data and Deviation Pointers would be displayed (RJAA VOR Rwy 16R).

Image 3: IAN has captured the localiser and the lateral Deviation Pointer is displayed as a solid magenta-coloured diamond.  FAC (in green) is displayed on the FMA.  The vertical Deviation Pointer is still in outline and in white (anticipation pointer), as is the G/P on the FMA.   IAN is tracking the localiser (RJAA VOR Rwy 16R).

Image 4: IAN has engaged.  The runway data is now sourced from the FMC and not the localiser (as in the above examples).  The FMA displays FAC and G/P in green colour, SINGLE CH is displayed, and both Deviation Pointers are solid magenta-coloured diamonds.  IAN has captured the Glide Path (RJAA ILS X or LOC X Rwy 16L)

Videos of IAN Approach

IAN APPROACH IN SIMULATOR

IAN APPROACH IN REAL 737-800 AIRCRAFT

Final Call

The use of Global Positioning Systems has enabled stabilised approaches at many airports, and the IAN system can take advantage of this technology to provide intuitive displays that support stabilised approaches on a consistent basis. 

Aircraft fitted with IAN are capable of using the APP button located on the MCP to execute an instrument ILS-style approach based on flight path guidance from the FMC.  This makes Non Precision Approaches easier to execute with increased safety.  It also enables a constant descent angle, less engine spooling, wear and tear, and improved passenger comfort.  Furthermore, IAN uses a standardised and consistent procedure, that in addition to improved displays and alerts,  can be used in place of LNAV/VNAV.

Nevertheless, a flight crew must be vigilant when using any automation, especially during the critical approach phase where there is little margin for error.  First and foremost is the innate ability to fly the airliner manually, and although automation such as IAN can enhance safety, it does so at the detriment of manual flying skills.

References

Several sources were used to obtain the information documented in this post, including: personal communication with a B737-800 pilot, the Boeing Flight Crew Training Manual and the Boeing 737 Technical Guide by Chris Brady.

If any discrepancies are noted in this article, please contact me so they can be rectified.

Acronyms and Glossary

• AGL – Above Ground Level

• APP – Approach button located on MCP

• CDU – Control display Unit (glorified keyboard)

• EFIS – Electronic Flight Instrument Display

• FAC – Final Approach Course

• FAF – Final Approach Fix

• FMA – Flight Mode Annunciator

• FMC – Flight Mode Computer

• FMS – Flight Management System

• G/P – Glide Path (Non Precision Approach / NPA)

• G/S – Glideslope (Precision Approach / PA)

• IAF – Initial Approach Fix

• IAN – Integrated Approach Navigation

• ILS – Instrument Landing System

• IMC – Instrument Meteorological Conditions

• MAP – Missed Approach Point

• MCP – Mode Control Panel

• MDA - Minimum Descent Altitude

• ND – Navigation Display

• PFD – Primary Flight Display

• RA – Radio Altitude

• RF – Radius to fix

• RNAV (RNP-AR) Approach - RNP-AR is a subset of an RNAV approach that requites authorization (RA) to fly

• Select – To select , arm or engage something

• STAR  -  Standard Terminal Arrival Route

Review and Updates

• 25 August 2017 - Review and content updated.

• 03 December 2019 - Review and content updated.

• 29 October 2019 - Review and content updated.

• 28 April 2021 - Review and content updated.  Release of .pdf.

• 21 December 2022 - Updated to latest procedure changes.

SISMO Soluciones - Avionics Review: My Negative Experience

I initially wasn't going to document my negative experience with Sismo Soluciones as many simmers use SISMO products and are fiercely loyal to this company.  This post has sat unpublished for close to 10 months until a friend convinced me otherwise, saying that bad reviews can be beneficial, especially to new simmers who are undecided on what and whom to purchase from.

This is the first negative review I have written and in doing so realise that I will no doubt annoy some people, especially loyal SISMO customers.  My aim is not to annoy, intimidate or create malicious rumours.  Rather, it is to share with others my factual experience with this company. Due to the negative nature of this review, it WILL NOT be posted to any forum.

I purchased the following units from SISMO:

• ADF radios (2)

• Transponder / ATC radio

• Audio Control Panel 

• rudder trim module

At the time, I was using Sim Avionics as my avionics suite.

I had issues with: aesthetics, quality assurance and the use of the SC Pascal script.  

When you initially look at the modules offered by SISMO, they do look attractive; however, it's often the small things that count and the panels made by SISMO lack the attention to detail and quality expected.

• This article is a little different from previous articles.  I've made a basic review of the modules, then discussed the issues I had in respect to with the panels/modules.  Finally I've discussed company.

Please note that I use the word panels/modules interchangeably.

Overall Module Construction and Appearance

The modules are constructed from acrylic and painted in Boeing grey.  The use of CNC machining produces a crisp finish resulting in cut-out lettering that is well defined.  This enables the lettering to appear very crisp when the panels are back it.  The buttons and switches used in the panels are machine injection moulded and secured to rotary stems via two small grub screws. The electronics are not sealed pr boxed (such as in CP Flight) but are visible.  DZUS fasteners are not included although holes have been drilled in the appropriate position (although these holes are too small to fit genuine DZUS fasteners).  The backing plate is made from plastic.

Paint Work

The paint work used by SISMO is not of a high quality.  The paint, eith minimal use of the panel, wears thin on the panel beneath the knobs and switches.  The paint also chips very easily and is not evenly applied to include the side of the unit.  Although I don’t know how many layers of paint have been used, I’d suggest it’s minimal.  Minimal paint saves time and expense and does not lend itself to high quality or longevity.

Integrated Backlighting (IBL)

View fullsize

SISMO ADF unit & FDS NAV1 unit.  Note the difference in backlighting (not seven-segmented displays) and module colour between the two units.  FDS use real aircraft bulbs

SISMO does not utilise real aircraft bulbs for backlighting.  Rather they use a number of strategically placed LED lights.

There are several arguments for and against the use of bulbs and LEDs.  The former provide a realistic throw of light at the correct colour temperature, while LED’s are usually more pin point, require less power to run, and usually appear colder in colour temperature.

The Backlighting on the SISMO modules is reasonable; however there is not an even throw of light across the rear of the panel to allow complete illumination of all cut out lettering.  The panel also does use a light skirt to inhibit stray light from illuminating the outer edge of the modules  The backlighting is powered by 12 volts.  The colour of the LEDS is amber yellow or warm orange.

I had an issue with two LED lights; The LED lights stopped working.  SISMO informed me I would have to repair this myself.  Shortly thereafter, a third LED light failed. This suggests that SISMO may have a quality issue in relation to the LEDS they use (at least in the batch I received).  I have little doubt that the LEDS are inexpensively sourced from China (ROC).

Electronics

The upper panel of the module is attached to the electronic circuitry within the lower section by a backing plate made from plastic.  It should be constructed from metal to aid in strength.  The electronics appear substantial and to be well built (appearance only as I did not bench test the electronics). 

System and I/O Cards

The modules are not standalone devices.  Depending upon your requirements, the modules require connection to various system and sim cards for complete operation.  As an example, to operate the ADF units and rudder trim module requires three GIC connection cards, an Ethernet motherboard card, and three servo-daughter cards – seven cards in total!  

View fullsize

figure 1: sismo card setup. there are lot of cards

Although there is nothing wrong with this method of operation, it does pose a challenge to find a suitable location to mount the cards.  The cards appear to be constructed to a high standard and are very solid; they do not feel or look like cheap Chinese-made cards.

I’ve included, for interest, a schematic wiring and card diagram of the module set-up for the Captain-side ADF radio. (click the image to enlarge the picture). 

The main Ethernet mother board requires a 5 volt power supply.

Wiring

SISMO provides you the opportunity to either use their prefabricated flat cabling or to wire everything yourself.  I choose the former and this saved a lot of time and frustration (wiring and soldering).  The flat cable packs are each fitted with heavy duty plastic clips for attachment to the cards.  Connection is straightforward and SISMO provide large A3 colour wiring sheets so you know exactly what wire plugs into what card.

If you decide to use the flat cabling, it’s necessary to include in your system a number of additional cards.  These cards, called  Generic Interface Cards (GIC) act as joiners between the different system cards used by the panels. The size of each GIC card is little larger than a credit card. 

View fullsize

SISMO panels with flat cabling.  There is a lot of cables that need to connect with several interface and GIC cards

Too Many Cards

The amount of wiring and number of cards needed to use SISMO products is ridiculous! 

Using four panels, the interior of the center pedestal is a mass of wires leading to and from various interface cards.  There are far better and easier alternatives available from other manufacturers.  

The Power of Ethernet

SISMO’s product range utilises Ethernet technology rather than USB; this has many advantages over the use of USB. 

According to SISMO literature: 'USB was not designed to carry the volume of information necessary for flight simulation. Although USB is practicable and does work very well, it can on occasion malfunction (drop out), or slow the operation of the intended device by creating a bottleneck for information flow.  Ethernet, on the other hand, has been designed at the onset to allow for high information flows ensuring fast and consistent transfer of information'.

An Ethernet cable is required to link the main Ethernet mother board, either directly to the computer or to a switch (if using two or more networked computers).

View fullsize

The two tabs overlap the OEM DZUS rails.  You must cut the DZUS rails to allow the module to fit the pedestal

Real B737 Center Pedestal - Not Drop & Fly

An important point to note is that the ADF and ATC radios will not drop directly onto the DZUS rails fitted within a real B737 center pedestal. 

SISMO modules have been designed so that the electronic boards, mounted directly beneath the panel, are flush to the edge of the panel.  What this means is that the panel cannot be placed directly onto a rail, as the electronics board abuts the edge of the rails. 

To allow correct placement in a genuine center pedestal requires that the DZUS rails be cut in the appropriate position.

All the other SISMO modules, other than the ATC and ADF modules drop onto the rails without an issue.  I'm unsure why this manufacturing inconsistency has occurred.

Misleading Information

During my initial research, I asked SISMO if their panels fitted a genuine center pedestal.  I also queried if OEM DZUS fasteners could be used.  Juan Ma (sales) stated that all SISMO panels were DZUS compliant and did fit genuine DZUS fasteners; however, when I told SISMO they didn't fit the rails, Juan Ma claimed he had misunderstood my question due to his poor understanding of the English language - he meant to say no rather than yes.

To utilise OEM DZUS fasteners, you will need to enlarge the attachment holes in each of the panels to enable the fastener to fit into the hole.  A word of caution here – SISMO use plastic backing boards which will crack easily if you are overzealous with a power drill (this is why I suggested, earlier in this article,  that metal be used.

Communication and Support

Support for SISMO is either directly via e-mail or by their dedicated forum.  All e-mails are answered quickly (in English or Spanish). JuanMa and Cristina answered all my e-mails in a professional level.  They are courteous, exceptionally patient, and very helpful; both strive to help you as much as they can.  

SISMO Modules - A Closer Inspection

ADF Radio Module

Initially, you’re impressed when you look at the ADF panels.  The seven segment displays, illuminated in either amber yellow or warm orange are easy to read, well lit, and appear similar to the displays you would see in a real aircraft. 

As you turn the rotary knobs to change the frequencies there is no catching as the knobs are turned, and the push-to-activate buttons move freely.  They do not stick in the down position when depressed. 

Problems

One small issue I immediately noticed, was that the tinted window plate which sits over the frequency display is not secured; as opposed to other manufacturer’s modules that incorporate the plate into the actual construction of the panel.  If you invert the modules the cover plate will fall out of the recess.  I decided this wasn’t a problem; how often are simulators inverted, and securing the plate is an easy exercise.  A small piece of double-side tape is all that is needed to secure the plate in place.

My problems began after roughly four hours of use.  The frequency push-to-activate button was temperamental and would not allow the stand-by and active frequency to be changed with one push; several pushes were required.   The problem was intermittent, but investigation suggested an issue with the clicking mechanism or the button itself.

The next issue to develop was with the rotary knob; turning the knob caused the frequencies to jump digits.  As with the push-to-activate button, the problem was intermittent but, the problem was rectified when you closed and reopened the SC Pascal script.  Perhaps the script needed tweaking.

Knobs and Switches - Poor Quality

I was disappointed with quality of the switches and knobs used on the panel.  The two ADF-ANT switches are made from hand injected low quality plastic; several small injection holes in the plastic are easily seen.   For the minor cost involved, high quality machine-injected knobs could have been manufactured.  

Each of the ADF-ANT switches slides onto and over the plastic circular shaft of the rotary mechanism.  The knob is then secured to the shaft by two grub screws each side of the knob.  It doesn’t take too long for the grub screws to begin to loose their grip on the shaft with resultant slippage of the knob.

Other companies have solved this potential problem by using D-shaped shafts or higher quality rotary switches incorporating metal shafts instead of plastic.  Knobs manufactured by high-end companies use stainless steel shafts and stainless grub screws that screw into stainless sleeves.

• My rating 4/10

Audio Control Panel (ACP/ASP)

View fullsize

SISMO ACP unit does not look realistic with inexpensive poorly moulded buttons and very stark backlighting.  Note that some of the rectangular buttons are not in alignment.  This unit has been constructed with very poor attention to detail.  Note, the black knob is not a SISMO knob but comes from a 737CL (OEM)

The Audio Control Panel (ACP/ASP) replicates the audio system of the B737 (navigation radios, etc).  The ACP occupies a large piece of real estate in the center pedestal and the ability to turn on and off navigation audio sounds should not be dismissed.

The main ACP switch is of similar construction to the ADF-ANT switches on the ADF module; it is poor quality with injection holes readily observed.  The clear push buttons used to turn on and off the various audio sounds are of low quality.  The buttons are fashioned from clear acrylic and lack detail and definition.  

I was disappointed, that when the ACP unit was fitted onto the pedestal, light from the backlighting seeps along the edge of the panel (to stop this I applied masking tape to the side of the panel to create a light skirt.  I also noted that some of the buttons are not accurately aligned with one another. 

Often it’s the small things that count and push a product to the next level. Clearly this is not a mantra that SISMO adhere to.

I was not impressed with the quality and attention to detail on the SISMO ACP unit; therefore, have decided to convert two real B737-500 ACP panels to simulator use.

• My rating 2-10

Rudder Trim Module

The rudder module incorporates a large knob that is center-spring loaded.  The knob allows the rudder to be deflected in either direction and be recorded in degrees of offset on the scale.  The movement of the defection needle is made possible with the use of small servo motor fitted beneath the module and powered by 12 volts.

View fullsize

SISMO rudder trim module.  Note the very poor moulding on the knob and colour shift with lighting

The rudder trim knob is poorly moulded and clearly portrays hollow holes left over from the injection process.  For those searching for aesthetics, replacement using a real B737 knob is very easy (if you can find a real knob).

The trim needle, at least on my module, is a little lop-sided.  As with the ACP module, stray light from the LED backlighting is readily seen around the edge of the panel.  Like other SISMO panels, there is no inclusion of a light skirt to stop stray light.

The remainder of the module is aesthetically pleasing.

The rudder trim is one of the modules that is necessary to complete a center pedestal, but unless one is regularly flying with one engine, the module is seldom used.  Therefore; this module from SISMO, even with the irregularities, is a reasonably priced alliterative to some of the more expensive counterparts available (provided a replacement knob is used and light skirt is fabricated).

• My rating 5-10

ATC (Transponder) Module

This is one of the better produced modules from SISMO. 

The switches and knobs are manufactured to a quality at least equal to what other companies produce.  There are no injection holes in the knobs, and turning the frequency knob is very smooth when altering frequencies. The digital read out is crisp, yellow amber in colour, and the tinted window, which falls out easily on the ADF panel, seems to be more secure (although it is the same drop in type).   As with the ADF panel, this panel will require you to cut the DZUS rails if you are using an OEM 737 center pedestal.

As a script was never supplied with this module (SISMO did not send it), I cannot provide information to how well it operated.  

• My rating based solely on appearance is 7/8-10

Reliability and Performance - Software and Modules

Software - SC Pascal Scripts

The modules require SC-Pascal scripts to be installed on the simulator computer. 

The basic script is downloaded from the SISMO website.  A further customised script is needed to configure the modules to the avionics software package you are using (Sim Avionics, Project magenta, ProSim737, Orion, etc) and FSX.  SISMO write the script dedicated to the panels you are using.  To activate the panels you run the executable file when you open a flight session.

SC-Pascal scripts are completely new to me, but a little research indicates that the script is used as a software interface between the actual functionality of the various panels, FSUIPC and simulator software.

Once the scripts are installed and configured correctly, a folder is created in which is stored the config.ini file and the executable script.  The folder and files can be named and stored anywhere on your computer system.   The panels are turned on by activating the executable script (.exe).  

As an option, direct access to the script can be made by adding the executable command to the auto start folder of your computer.  This option automatically starts the modules when the computer is turned on.  The script then runs in stand-by mode until flight simulator is turned on.  This option saves time and repetition by not having to turn on the executable file.

As SISMO utilises Ethernet technology, the various IP addresses of the computer (s) you are using need to be correctly configured to allow communication between the computer and the panels.  This is basic networking knowledge and is relatively easy to learn.

Once the software is configured, the software and modules should function flawlessly.  

Script Problems

I did have some issues with the SC Pascal script freezing when it was initiated.  The script also caused some issues which appeared to cause the ADF radios to incorrectly display frequencies.  To Juan Ma's credit, he did tweak the script, however, the problems remained.

As I know nothing about SC Pascal scripts, I don't know with certainty whether the problems experienced were caused by a script issue, hardware issue, or something particular to my system.  If push comes to shove, my guess is that the problem lay with the SC Pascal script.

I try to keep things simple in my simulator, and running multiple scripts for various panels through several interface cards doesn't exactly fit into this ethos. 

It would be inaccurate to state that SC Pascal scripts don't work, because there are many enthusiasts who have them operating perfectly.  But, I am not one of these individuals.

Note that I was using Sim Avionics.  If using ProSim737 there is an option to use a script or direct drivers within ProSim737.

Quick List - Pros and Cons

PROS

• Fairly accurate 1:1 ratio (or close to)

• Easy to install and use software (knowledge of SC Pascal required if altering software)

• Laser cut and stenciled lettering

• Ethernet technology

CONS

• Plastic shafts on ADF-ANT knobs (should be metal/stainless)

• Poor quality knobs and switches on ADF, ACP and Rudder Trim module

• Average light coverage for LED backlighting

• ADF and ATC modules don't drop directly onto DZUS rails; the rails must be cut.

• Large number of cards needed for operation

• Not DZUS complaint (requires existing holes to be enlarged)

• Plastic backing plate on panels (easily damaged when enlarging holes for DZUS fasteners)

• Light seepage around edge of some panels from backlighting (no light skirt)

• SC Pascal script troublesome and works intermittently.

• Poor quality paint work

Considering the above, the panels are expensive.

Final Call

The modules are ideal for the budget-conscious flight simmer.  This said, a potential user must have knowledge to troubleshoot problems.

The lack of quality knobs, switches and poor attention to detail detract aesthetically, while the large number of cards that need to be installed can make installation challenging.  Three failing LEDS and problems with the frequency selector switch on the ADF radio panel may point to quality assurance issues.  The use of Ethernet over USB is highly commended and may reduce information bottlenecks.

My rating for the software is 4/10 (The supplied scripts didn't work with my system, which at that time was Sim Avionics and not ProSim737).

My overall rating for the modules is 3/4/5-10 (based on fitting issues, quality of knobs, poor attention to detail, poor painting, no light skirts and temperamental frequency selection switches on ADF).

Please note that this review is my opinion only and is not endorsed.

POST SCRIPT: - July 15, 2012 - RETURNED MODULES TO SISMO REQUESTING REFUND

I have returned all the panelss, cards and wiring  o SISMO for a full refund (minus freight).

Initially, SISMO offered me 10% of the value of the products purchased (this included the interface cards that had never been used).  

SISMO stated that the return period had been exceeded, and any products returned would be treated as second hand units.  It didn’t matter that SISMO had not, at that time, sent all the appropriate SC Pascal scripts to ensure correct operation of the modules.  

The writing of the SC Pascal scripts was delayed close on 2 months after I received the modules, and when received, the scripts didn't funcyion as intended.  Excuses were; staff holidays, workloads, Easter break, and awaiting confirmation from another company to facilitate operation.  

Upon receipt of the returned items, SISMO claimed that many of my issues were incorrect or not relevant.

• They claimed that the modules had been damaged.

• They stated that I had broken the LEDS (I told them the LEDS were not working when I received the parcel).

• They claimed I had disassembled the units and damaged the paint and screws.

• They claimed I had re-painted portions of the units.

• They claimed sticky plaster was attached to one of the units. (this is correct as I used tape to secure the wiring & also to create a trial light skirt)

• They deducted from my refund, Spanish import duty and inspection fees (returned the goods to Spain).

• They claimed I did not include paperwork (which I did). 

• They stated that as the ATC RADIO module was discontinued, a refund was not possible.  At the time of purchase they did not inform me this panel was discontinued.

I'm not going to go into a long account to what has transgressed.  But, I will say that this company cannot be trusted…..They promise the world to you, but if you aren't happy with the products, they provide every excuse possible to NOT provide an adequate and reasonable refund.

For example, when I reported the failure of the LEDS to SISMO, their response was 'they worked when they left the shop'.  They did offer to replace the LEDS but, at my shipping expense (which was expensive).  They also offered, because of the inconvenience caused, a discount on further purchases.

It should also be noted, that in my initial correspondence with SISMO, I asked whether their panels would drop directly into an OEM B737 center pedestal.  Juan Ma stated 'YES'.  However, on receipt it was discovered that the modules were too large to fit directly onto the pedestal DZUS rails.  I queried Juan Ma from SISMO on this; he stated that it was a language misunderstanding.

Juan Ma understood perfect English when it came to avoiding a refund of purchase money.

Legislation, PayPal and Delays

Spanish legislation states that every purchase has a 7 day cooling off period, in which a return and refund can be made.  PayPal policy states you have 45 days in which to make a claim.  EU legislation states that refunds are possible if items do not function correctly - within a set time frame.

Without a working script for Sim Avionics (which took two months to receiveve), how can testing of panels occur.  Because of the approximate two month delay on sending operating scripts to me, all options available to me had expired.

I cannot help but think that SISMO delayed the sending of the scripts so as to provide a reason for NOT refunding 100% of the purchase price.

SISMO Solicones appears to be a company that will ONLY support and stand by their products if you continue to use their products and not complain, or attempt to return them.

If you ask for a refund due to faulty components, components that don't function, or scripts that don't function correctly, then expect NOTHING, or at the very least, a minimal refund (and you will have to fight to get this refund). 

What you can expect from SISMO, is e-mail after e-mail informing you that you have no right to a refund, that you have damaged the items, and that you did not follow SISMO policies, etc, etc.

After many e-mails, I succeeded in gaining a E400 Euro refund for an initial E1400 Euro outlay.

I'm sure there are many happy customers using SISMO products; however, I am not one. I do not recommend SISMO Solicones. 

Their products are of poor quality.  The attention to detail that is required (and expected) when replicating an aircraft panel is very poor.  And finally, their customer service is dismal if you are seeking to return an item.

In my opinion, it's VITAL that a company standby and support their product-line, and this includes refunds if the product (for whatever reason) is not suitable with your simulator set-up.

If you search the Internet, you will find very few comments regarding SISMO, other than company endorsed reviews on forums that are supported by manufacturers and resellers.

If you are searching for quality avionics panels, look no further than Flight Deck Solutions or CP Flight. 

These two companies are reliable, produce quality products and provide exceptional after sales service.  They also offer a refund if not 100% satisfied with their product.  Whatever you do, don’t spend your money on inferior products from SISMO! (my opinion only).

• This review is rather negative towards SISMO Soluciones.  I have 'toned down' my anger to this company considerably in an attempt to produce a balanced and accurate review.  Please understand that this is my experience with this company.  Your experience may well differ. 

Feel welcome to make comments, either good or bad in the comments section.

Updated and Amended 15 April 2020

Update

on 2015-08-27 00:15 by FLAPS 2 APPROACH

I wasn't expecting such a response to this post.  Nor was I expecting SISMO Soluciones to link this negative review to their website, face book account, and on several other prominent forums.

Whether an individual likes or dislikes a product based on aesthetics and functionality is subjective; what I dislike, another simmer may like very much.  I know several simmers that use SISMO and are very happy with the product. 

My main 'gripe' with SISMO, apart from poorly produced products, is their no questions non-return option should you be in the former (dislike) category.

Whatever transpired between myself and SISMO is water under the bridge.  If a company stands by their products they offer a no questions return policy.

I have since heard, based upon this review that SISMO may be taking legal action against me for what I have written.  I have told the story as it unfolded and refuse to retract what has been written on an independent and non-industry supported website. 

• This is one of the purposes for this site - unbiased and honest appraisal of products I have used.

Thanks for your lively comments.   Cheers

Replacement OEM 737-500 Throttle & Center Pedestal - Conversion to NG Style

View fullsize

737-300 throttle quadrant with old style paddle-style stab trim levers

The last few months have seen quite a bit of activity regarding the throttle quadrant and center pedestal, which has culminated in me selling my former 737-300 series throttle quadrant and pedestal and replacing it with an another unit from a late series 737-500 aircraft.

Brief Recap

In late 2012, I decided to convert the 737-300 throttle to full automation.  A dilemma I faced was whether to keep the throttle unit as a 300 series throttle with the attached two-bay pedestal, or do a full conversion to make it similar to the Next Generation. 

After careful consideration, it was decided convert the throttle quadrant.so it appeared as close as possible to the Next Generation.

Stab Trim Switches

One of the biggest differences, apart from thrust lever handles, between early model throttle units and the Next Generation units is the stab trim cut out switches.  On the earlier 300 series units, the switches are paddle / lever style switches while the Next Generation uses toggles and T-Locks.  T-Locks are a safety feature and sit beneath the toggle switches and are spring loaded; the pilot must push down the T-Lock to activate the toggle.  

To convert the trim switches requires cutting out the old switches and fitting new reproduction Next Generation switches.  This is a major task requiring precision work.  Although reproduction switches can be made, the reproduction T-Locks don't operate as the real T-Locks should.  I did search for some genuine T-Locks and toggles, however, my search was fruitless as these parts appear to be reused by airlines (or recycled).

Replacement 500 Series Throttle Quadrant & Three-Bay Center Pedestal

A friend of mine informed me that a late model 737-500 throttle quadrant was for sale.  This unit was in better shape than my existing throttle, included the genuine Next Generation style stab trim switches complete with T-Locks, and also had a three-bay center pedestal.  It appears provenance was shining on me as the new throttle appeared for sale a day before the stab trim switches were about to be removed (with a metal cutter...)

The throttle and center pedestal were purchased (you only live once!) and the 300 series throttle sold to an enthusiast in Sweden.

Next Generation Conversion

To bring an earlier style throttle and center pedestal to appear similar to a Next Generation throttle quadrant requires, at a minimum:

• Attachment of a Next Generation style throttle lever shroud to existing aluminium levers;

• Removal of TOGA buttons and relocation to bring design in-line with a Next Generation (the buttons are identical, but the housing is different);

• Possible replacement of the stab trim switches;

• Painting of throttle housing and center pedestal from Boeing grey to Boeing white; and,

• Painting of all throttle knobs from Boeing grey to Boeing white.

The biggest hurdle is usually replacing the trim stab switches, however, as these are already present on the new throttle, and are the Next Generation, considerable time and expense was saved in not having to replace them.

Main Differences - Next Generation & Classic

The Boeing airframe that most people associate with today begins with the 737-200 and ends with the 737 Next Generation.  In between we have the classics which refer to the 737-300, 400 & 500 series airframes. The 737 Next Generation series includes the 737-600, 700, 800 & 900 series airframes.

The main differences between a classic and Next Generation throttle quadrant are:

• The stab trim switches are slightly different; the classics having two flat levers while the Next Generation has toggle-style buttons with T-locks;

• The throttle thrust lever handles; the classics are bare aluminium and the Next Generation is white aluminium that is ergonomically-shaped.  The TO/GA buttons are also positioned in a different place on the Next Generation.  The knobs (handles) on the levers are also coloured white rather than off-grey;

• The method that the throttle thrust levers move during automation.  The classics move both thrust levers together when auto throttle is engaged.  The Next Generation moves each lever individually in what often is termed the throttle dance (this is due to the computerised fuel saving measures incorporated in the Next Generation);

• The spacing (increments) between each flap lever position is identical in the Next Generation, but is different in the earlier series throttles;

• The center pedestal in the classics is either a two-bay pedestal (early 300 series and before), but more likely a three-bay pedestal.  The Next Generation always has a three-bay pedestal.  Base materials for the center pedestal are also different - aluminium verses a plastic composite material;

• The speedbrake knob is very slightly more elongated on the Next Generation unit; and,

• The telephone, circuit breakers and mike assembly differ in type and location

Next Generation Skirt - Thrust Levers

Boeing when they designed the Next Generation style throttle didn’t design everything from new; they added to existing technology.  All Next Generation throttles utilise thrust levers which are identical to those of earlier units.  

Boeing designed a shroud or skirt that attaches over the existing thrust levers encapsulating the older thrust levers and sandwiching them between two Next Generation pieces.  The assembly is made from aluminium and is painted white.

The TO/GA buttons are located in a different position on the Next Generation units, although the buttons used are identical.

To alter the position of the TO/GA buttons you must detach  the small aluminium box from the 300 series thrust levers, remove the TO/GA buttons, and then re-solder the buttons in the appropriate location on the new unit.

I did not make the Next Generation skirt for the thrust levers, but rather had fabricated, from design specifications, a reproduction skirt.  The skirt is produced from aluminium and replicates the dimensions of the Boeing part.

Time-line, Functionality and Conversion

The throttle is initially being converted in the United States.  The advanced work (automation) will be done by a good friend in California, and then I will follow on with more mundane tasks.

The replacement unit will feature several improvements which will allow: full motorized functionality, full speed brake capability, accurate trim tab movement, alternate trim wheel spin speeds, correct park brake release, trim wheel braking and several other features. 

I want the functionality of the throttle to be as close as possible to that found in the real aircraft; therefore, the methods used to ensure this functionality will be slightly different from the norm.

When the throttle is fully functional and tested, I'll publish a post providing further information and detailed photographs of the various functions.

It is hoped everything will be completed, and the throttle and pedestal installed by late May 2013.  The next month or so will be quite exciting.

Two-bay Pedestal Will Be Missed

I know I will miss the narrower two-bay center pedestal.  A major advantage that will be lost is the ease in climbing into and out of the flight deck; the two-bay provided more room between the pedestal and the seats.  At some stage, I probably will need to install J-Rails because the seats I'm using are fixed-claw feet Weber pilot seats; J-Rails will be needed to allow lateral seat movement.

BELOW:  Montage of several images showing main visual differences between 737-300 classic series throttle quadrants and the 737 Next Generation. The 737-300 throttle is my old throttle but, the Next Generation throttle quadrant belongs to a mate of mine.

View fullsize

Montage of several images showing main visual differences between 737-300 classic series throttles and the 737 NG style throttle units. The 300 series TQ is my old throttle unit but, the NG Throttle quadrant belongs to a mate of mine

B737-300 Throttle Full Automation Upgrade

View fullsize

oem 737-300 throttle formally used by South West Airlines. Note grey coloured throttle levers and raw aluminum handles. The boxes that contain the TOGA buttons can just be seen

The throttle quadrant installed in the simulator is from a 737-300.  When I initially  converted the throttle for flight simulator use, I choose to not have full automation included; automation being at the time fraught with issues in relation to correct and accurate operation.  

Technology rarely remains stationary and after one year of operation I’ve been reliably informed that automation can now be implemented without the problems previously experienced.  Therefore, I’ve crated the throttle quadrant and it’s now on its way to the US via DHL courier for conversion to full automation.  A process I am told that will take a few weeks.

Automation will include, at the minimum, the following:

• 4 speed trim wheels dependent upon aircraft status (as in the real aircraft)

• Accurate trim tab movement

• 9 point speed brake (speed brake operation as in the real aircraft)

• Full automation of throttle thrust handles as per MCP speed window and/or CDU

• Hand brake release by depressing brake pedals (as in the real aircraft)

I don’t mind admitting that that my building abilities don't include complete knowledge on how to convert a 737 throttle correctly - especially in relation to automation; therefore, this task has been outsourced.

The method in which automation will be achieved is slightly different from the usual way throttles are converted, and includes some magic programming of chip sets and machining of parts to allow compatibly with ProSim737.  Taking into account Christmas and New Year, I'm hoping that the machining, installation, configuration and testing will be completed by January (2013) and the throttle will be re-installed into the simulator by February.

In a future post, I will explain the process of conversion, and how automation has been achieved with minimal use of add-on software.

Idle Time

Although the throttle quadrant and pedestal will be absent from the simulator for a short time, work will not be idle.  The conversion of the twin real B737 yokes and columns has been completed and I'm finalising installation of the second platform which incorporates linked 737 rudder pedals.  I am hoping this will be completed by mid-November.  I have discussed the new platform in a previous post.

JetStream 738 by ProSim737 - Review

View fullsize

After flight testing several aircraft models, I decided to use the B738 (FS9 version) produced by Precision Manuals Development Group (PMDG).  This flight model, once the PMDG flight logic is removed, functioned exceptionally well and is very stable.   

One of the potential problems when using a flight model produced by another company is compatibility and functionality with your chosen avionics software suite.  Minor problems are often solved by tweaking the aircraft.cfg file; however, tweaks are just that, and often issues will occur which cannot be identified and rectified.  In my experience, tweaking the .cfg file may solve your initial problem, but may cause additional errors elsewhere.

Different Aircraft Models – Different Solutions

To ensure various aircraft models operate with their software, Sim Avionics provide users with specific aircraft.cfg files that correspond to the particular flight model they are using.  These files are optimally tweaked to the Sim Avionics software.

ProSim737 has handled the problem of aircraft model variances slightly differently.  Rather than provide a tweaked aircraft.cfg file to allow you to use whatever flight model you wished, they took a holistic approach and produced a complete aircraft dedicated ONLY to their avionics software suite.

Creating an aircraft model that is designed to only operate with their software has many advantages.  First and foremost is trouble-shooting.  Everyone is using the same software, meaning that if a problem does present itself, finding a solution is usually easier.  Chasing ghosts rarely occurs as the same company that produced the avionics suite produced the aircraft flight model.

At this stage, you may think that ProSim737 only works with their dedicated aircraft.  This is incorrect; ProSim737’s avionics suite will work with numerous aircraft models including the default FSX 737 and the PMDG FS9 737, however, if you want to achieve harmonious inter-connectivity with the avionics software, then using the dedicated flight model is highly recommended.

Hello JetStream 738

The JetStream aircraft is more a flight model than an actual virtual aircraft.  Don’t expect to see “wow” factor visuals with this model.  Instead, expect to experience “wow” factor flight dynamics that work in perfect unison with the flight avionics software.

Virtual pilots using a fully developed simulator often do not need what is offered in many aircraft models: virtual flight decks, pop-up gauges and GPS consoles are not necessary.  As such, the JetStream doesn’t provide these additives.  You will, however, see the default FSX panel layout of the B737.  This can easily be permanently removed by either editing the panel.cfg file or removing the panel images.  

Installation

The JetStream software comes with an .exe installer.  Installing is as easy as following the prompts.  When installed, a JetStream 738 folder will be found in the simobjects/aircraft folder.

JetStream Textures

The Jetstream uses the default texture pack belonging to the B737-800 FSX aircraft; therefore, the outside views mimic the same texture details seen on the default FSX model.  

I think the outside textures (especially with a repainted airline livery) are just as good as many payware add-on aircraft textures.  Certainly, PMDG NGX textures surpass the JetStream textures, but you must remember that the aircraft has NOT been designed as a pretty aircraft to look at, but a flight model to replicate defined flight dynamics.  Think of it as flying ones and zeros.

Video Makers & Virtual Airlines

Video-makers or those who wish to mimic a particular airline can easily re-texture the aircraft skin to reflect a specific colour scheme or airline livery.  Search through the ProSim737 forum and you will find several dozen repaints.  Installing additional textures is identical to the method used in FSX.

If you search this website you will find mention of the 164 liveries pack.  This pack provides many liveries and re-textures.

Outside Views & Animation

Many individuals concern themselves with the outside view of an aircraft.  Whilst it’s enjoyable to inspect the aircraft from the outside, the quality of the external visuals has absolutely nothing to do with the way the flight model behaves.                    

This said, the movement of essential equipment can be observed: the rudder, flaps, ailerons, spoilers and landing gear.  Landing and other outside lights are also replicated including a functional taxi light which is bright enough to “read by”.  The outside view is far from sterile.

Taxi Light – Too Bright & Intense

One downside to the external view is the actual positioning the taxi light.

Historically, Micro$oft have never animated the taxi light correctly.  ProSim737 have created their version of a taxi light, which is more a ball of light than a taxi light.

The taxi light is bright – very bright.  On lift off, the fall of the light beam covers the lower portion of the front screen view.  This obviously does not occur in a real aircraft.  Although I have not altered the files, I have been informed that this cosmetic issue can be rectified with a small tweak to the aircraft.cfg file.  

I would have liked ProSim737 to have developed the external lights from scratch with a dedicated taxi light with no fall off on the lower portion of the computer monitor.  Good external lights are essential if you fly predominately at night.

Flight Dynamics – flying Ones & Zeros

This is why the JetStream was developed – as a platform to replicate complicated flight dynamics to realistically mimic the movement and handling of a real jet aircraft.  This is where the wow factor begins and is where the JetStream leaves it’s contemporaries behind.

I am very impressed with the flight dynamics.  During several hours flight testing, the model was exceptionally stable, handled as you would expect, and interfaced with the ProSim737 logic flawlessly.  

Fine-Tuning & Stability Testing

ProSim737 has been designed to be operate with MCPs (Main Control Panel) manufactured by several companies.   I have been informed that, depending on the MCP type, problems can be experienced with the sensitivity of the auto pilot.  To alleviate this, ProSim737 allows the sensitivity of the MCP to be adjusted.

The JetStream manual suggests that a good method to determine possible over-control (i.e. oscillations) is to increase the simulation speed to 4x and observe if oscillations occur, and if the autopilot is able to hold either heading or altitude”.

I performed this stability test at x4 acceleration and noted very mild pivoting of the wings as the aircraft slewed along it defined navigation track.  When I morphed back to normal speed, the aircraft was in the same direction, attitude and altitude that it was when I entered acceleration mode.  Only at faster acceleration speeds (x16) did the aircraft loose position (which is to be expected).

Hardware Calibration

The JetStream requires careful and fastidious calibration of your yoke and rudder pedals to ensure solid performance.  

Calibration isn’t as important if you use the auto pilot to do most of your flying, however, if you prefer to hand fly to and from FL10, correct calibration of your yoke and rudder is paramount.

It’s essential to take the time to calibrate your hardware correctly using the Windows and FSX calibration tool, using FSUIPC to fine tune the results.

Your hardware control settings play a huge role in how the plane behaves, so before blaming the flight model, please test it with different controls and settings.  

The following is an excerpt from the JetStream read me file:

• Most 738 models available represent a truly overpowered engine/dynamics ratio, The flight model tries to follow the real curve, don't expect it to reach high speed/AOA values as other flight models do, especially immediately after rotation.

• As in FSX, nose-steering is nothing else but rudder, without FSUIPC's given steering routine and a hardware wheel, do not expect acceptable results on the ground.

• The VC was deliberately removed from the model.

• Trim related values do depend on hardware behaviour.  This relates to whether hardware has been calibrated with or without FSUIPC.

• Idle N1 value is OAT dependent. You will get 20.7 at 15C.

• Set General Realism Slider to Maximum! It is vital for the model!

PMDG (FS9) and Default 738 Verses JetStream

I outlined in the opening paragraph that ProSim737 can be used with several other add on aircraft, including the default FSX 738.  My limited testing proved that these aircraft fly well with ProSim737, however, nuisances do occur and tweaking of the aircraft .cfg file is needed to solve niggling problems with often undesirable outcomes..

The JetStream was designed from the bottom up to be the flight model for ProSim737.  Therefore, many of the nuisances observed when using other flight models do not exist.

As an example, the FS9 version of the  PMDG aircraft at Vr, with the yoke pulled to aft position, exhibits a slight delay of a second or two before actually lifting off the runway.  A positive rate is rarely achieved before V2 is called.  This is completely different with the JetStream which is far more responsive.  Pull back slightly on the yoke at Vr and the aircraft is airborne before reaching V2.

No matter what I did with the PMDG flight model, the only way to achieve rotation at Vr was to pull back on the yoke a few seconds before actually hearing the Vr call out.

This is but one example, illustrating why it’s solid sense to link a dedicated flight model to a specific avionics software suite to achieve harmonious integration.

FS Add Ons - Top Cat Compliant

Many virtual pilots use a popular add on flight tool called Top Cat.

Top Cat is used, amongst other things, to calculate weight, takeoff and landing performance.  The JetStream is compatible with Top Cat and the JetStream manual explains how to incorporate this advanced FS add on.

JetStream User Manual

A detailed user manual is included which is well written and informative.  It’s important to read this manual to ensure you get the most from the JetStream flight model.

Updates & Improvements

ProSim737 currently produces one aircraft and one avionics software suite.  While some may find this lacking, I find it reassuring.  Rather than become tired down to developing other aircraft and software, ProSim737 focus their attention on one aircraft – the B738.  This translates to regular updates and improvements which can only benefit the end user.

Support

Support is provided either by a dedicated forum or via personal e-mail communication.  

To date, all requests have been answered quickly and efficiently.  If you need help, support is available.  You are not left to feel as if you’re withering on a vine, waiting for assistance.

I try to be impartial and accurate when I make a review, however, if I have missed something or have made a mistake, feel free to make a comment.

This review is based solely on my experience with the JetStream and ProSim737.  I have no affiliation with the company.

My Rating is 9/10

View fullsize

View fullsize

View fullsize

View fullsize

View fullsize

View fullsize

View fullsize

View fullsize

Throttle Thrust Problem - Loosing Thrust at N1 - The Solution

View fullsize

oem 737-300 throttle

The throttle installed into the simulator is a converted genuine B737-300 throttle.  Lately, I have observed inconsistent power thrust issues during the take off roll and climb out. 

As I begin the take off roll, engage TO/GA and rotate, but before acceleration altitude or acceleration height is reached, one of the throttles looses or gains power.  Moving the throttle handle reinstates throttle power, but the power is dependent on where the actual throttle lever is physically positioned. 

When the aircraft is above thrust reduction altitude (1500 radio altitude) the problem rectifies itself.  The problem cannot be replicated when flying above 1500 feet.  I also noted, and this may also be part of the issue, that the power indicators located on the EICAS display fluctuate (twitch) a little as I moved the throttle levers.

This problem only began to occur after I transferred the avionics software to ProSim737.

Process of Elimination

Problems like this are not uncommon when interfacing real aircraft parts and the challenge is finding the cause of the problem.  The only method to determine solutions to problems such as this is to systematically, through the process of elimination, identify the problem area.

My first thought was that one of the potentiometers in the throttle quadrant maybe damaged, although I considered this to be unlikely as the units are still relatively new.  The throttle has four potentiometers: throttle 1, throttle 2, flaps and spoilers. Flight testing indicated that the power loss alternated between engine 1 and engine 2; therefore, the likelihood of two potentiometers failing at the same time was minimal. 

The next step involved checking the wiring within the throttle quadrant, to ensure there wasn’t damage to the outer coating of the wires.  A damaged or loose wire can easily short on the throttle frame and generate a spike.  However, if the wiring was loose or damaged, the problem would also occur when flying at altitude, and I had clearly demonstrated that the problem only occurred during the take off roll and climb out to thrust reduction altitude. 

The next step was to ensure that calibration of the throttle unit was correct.

Re-Calibration Using FSUIPC

I decided to re-calibrate the throttles using FSUIPC rather than FSX.  This process isn’t difficult and FSUIPC allows you to fine tune each throttle with greater accuracy than is possible with FSX. 

After re-calibration, the “twitching” of the power indicators ceased, but the initial problem remained.

The Cause of the Problem

The only culprit I could think of to cause this problem was ProSim737.

To check whether ProSim737 was actually the cause of the problem, it is necessary to remove any input from the ProSim737 software.  This is straightforward.  Either use another avionics software package or use FSX itself.  I did twenty trial flights using both Sim Avionics and FSX and the problem did not replicate. 

ProSim737 Excellent Support and Advice

I contacted the developers at ProSim737 explaining my problem in detail, and I received a response to my questions within a few hours.  Marty was especially helpful and we discussed several potential reasons for this issue and possible workarounds.  I must stress that the response I received from ProSim737 was absolutely 100% top notch. 

Marty genuinely wanted to help resolve the issue – whether it be with ProSim737 or otherwise.

Real B737 Throttle Operation

Now this where the comment “as real as it gets” does have meaning…. 

The developers of ProSim737 have designed their software to replicate the logic used by the real B737 auto throttle.  The software (ProSim737) is doing exactly what it’s supposed to do in relation to power thrust, and the issue I was experienced is caused by using a real aircraft throttle without automation.  Let me explain.

In the real aircraft, when TO/GA is enabled, the auto throttle logic has control of the aircraft.  The throttles are off-line and power thrust cannot be manipulated by the pilot.  The flight mode annunciator (FMA) illuminates N1. 

As 84 knots is passed the FMA changes from N1 to THR HOLD.  At this time, the actual throttles come back on-line, meaning that you can manually alter throttle power by moving the levers.  After rotation and at 800 radio altitude the auto throttle system is ready to change from take off power to climb power and the FMA changes from THR to ARM.  When in ARM mode the throttles are still on-line. 

When the aircraft reaches 1500 RA which is the thrust reduction altitude, the throttles go off-line and the AT logic is controlling the power thrust of the throttles.  The FMA changes from ARM to N1.

Throttle Anomaly

The B737 does not have a manual throttle, but an automated throttle.  The software is programmed to move the throttle levers to the correct position mimicking the actual power thrust called for by the auto throttle logic.

If you use a manual throttle (genuine or otherwise) the connection to the automated physical movement of the throttle levers is missing; you must counter this by moving the levers yourself.  This issue should not occur with a correctly calibrated automated throttle.

Using an Auto-throttle

If you have an auto throttle, the levers will automatically and physically move to the indicated thrust position as determined by the auto throttle logic (90%N1 at TO/GA).  When the FMA illuminates THR HOLD at 84 knots, and the throttles come back on-line for possible pilot intervention, the auto throttle logic will not sense any change in the throttle lever position, and power thrust (90%N1) will be maintained.   This is because the automated system placed the throttle levers in the correct position when TO/GA was initiated.

Using as Manual Throttle

However, if you’re using a manual throttle, the throttle levers MUST be physically positioned at the correct location on the throttle quadrant, otherwise the auto throttle logic will sense a change in position of the levers and alter the power thrust accordingly to this new level. 

This is what was occurring in my situation.  I was resting my hand on the throttle and only advancing the levers 3/4 of the way forward.  TO/GA indicated 90%N1, but when the throttles came on-line at 84 knots, the auto throttle logic noted that the position of the throttle levers was not at 90%N1 and subsequently altered the power thrust accordingly.

The reason the issue was inconsistent is that I didn’t always advance the throttle levers to the same position, and if I did the problem did not occur.

LEFT:  B737-300 throttle quadrant converted to Flight Simulator use.  The TQ is a manual throttle meaning that the thrust levers are not automated and must be moved manually.  I have used a pencil to lightly mark the metal adjacent to the most commonly used N1 settings.  This ensures the levers are moved the correct location during take off.  Lever position is set to 90%N1 and flaps 5.

Solution – Change in Procedures

The solution to this anomaly of using a real “manual” throttle is relatively simple.

You must determine where on the throttle quadrant the various N1 power settings are and then ensure, after engaged TO/GA that you move the throttle levers to the correct position (90%N1).  In my situation, the procedure is to advance the throttle to 40%N1, engage TO/GA, and then manually push the throttle levers to 90%N1.

Thank you

I’d like to thank Marty at ProSim737.  Marty worked with me to solve the issue, which ultimately was not really a problem with either ProSim737 or my set-up, but is an anomaly of using a genuine throttle unit without automation.

Possible Update

I may update the throttle quadrant to enable automation of the throttle levers and speed brake, however, for the time being the throttle quadrant will not include automation.

Update

on 2013-04-23 23:56 by FLAPS 2 APPROACH

View fullsize

diagram 1: a clear diagram that helps explain the problem discussed in the article (thanks to frazier @ prosim737 forum)

Sim Avionics Flight Software - Review

View fullsize

I've heard it said that a "simulated flight deck is as good as the software behind the scenes" and I agree with this comment: a flight deck with poor software is a hive for frustration, disappointment and time wastage.

It's easy to write about the features and functionality of Sim-A as they are plentiful; but, I don't want to become too bogged down in minute detail, otherwise I’d be writing a manual.  This review will not address in detail everything that Sim Avionics (Sim-A) software can or cannot do; if your interested in a full functionality list, it’s best to check their website, as functions are altered and improved upon on a regular basis. 

Before continuing, it should be noted that there are several flight avionics suites currently available on the market.  They all replicate the basic avionics functionality of the B737.  However, not everything is operational with each suite and some functions behave differently between suites.  Therefore, it’s a good idea to research what works and what doesn’t before your purchase. 

Sim Avionics is a complete avionics solution providing the avionics software needed to build a fully functioning home cockpit; no other software is required.  It has been designed to run on multiple PC's in various configurations interfacing with FS2004 (FS9) or FSX via FSUIPC and Wide Client.

Relative Newcomer

Although a newcomer to Sim-A and still learning some of the more advanced features of the software, I thought it pertinent that I make an "introductory review".

Reliability

Reliability is the most important aspect of any software.  To date, Sim-A has performed as one would expect from any high-end payware software. Overall, the software is reliable, performs well, and appears to be a robust and stable platform with consistent responses.

Certainly, it seems much more stable than some of the competitors on the market (if comments on flight simulation forums are anything to go by) and is far easier to use than some other well known brands.  But, it must be remembered that the software is only as good as the information inputted; therefore, if you try and do things that the aircraft & software is not designed to do, expect problems.

Further, you must bear in mind that no one computer (PC) is the same as another.  Different drivers, software, flight models and hardware configuration can cause any software to behave erratically from time to time.

This said, Sim-A can on occasion produce spurious results.  This is mainly associated with the more advanced auto pilot functionality and user operator errors!  

I’ve documented the issues and fixes, including some user operator errors, that troubled my installation below.

Issue 1 - Trim Tab Dancing

Now and again the trim tab will become unstable as the auto pilot continually recalculates the required pitch for the aircraft at the current speed.   The trim tab will “dance” causing the aircraft to pitch up and down. The trim dance (as I call it) occurs only on flights that have weather depicted, and it doesn’t occur on every flight.

FSUPIC to the Rescue

Although a little disconcerting, I believe the cause is not so much Sim-A, but the way the weather, especially aloft winds, are generated causing the elevator to continually move to counter weather differences.  There is a tab within FSUPIC that stops the elevator trim from operating when the aircraft is in auto pilot mode.  Since checking this FSUPIC setting (placing a tick in the box), the trim dance I was observing has decreased markedly and is now nonexistent.

Information for the auto pilot is located within the aircraft's configuration file.  If auto pilot trim issues persist then some minor tweaking of the numbers maybe required.  If this happens to you, then be rest assured that FDS and Sim-A staff will assist you with any minor tweaking to get you flying.

I’ve discovered that if the auto pilot does not provide consistent outputs (such as trim dancing), an easy method to often solve the issue is to switch the auto pilot command button off and then back on. 

Issue 2 - V-Nav Inconsistency

Replicating the more advanced B737 auto pilot functions requires complicated algorithms.  This is especially so with vertical navigation (V-Nav).  

Sim-A handles V-Nav reasonably well, although you have to keep an eye on what V-Nav is doing, espeially when transitioning from level flight to descent and approach.  On some flights, V-Nav honours the speed and altitude restrictions and transitioning the STAR to approach is accurate.  However, at other times restrictions are not followed and the aircraft will overshoot the height and speed restriction.

V-Nav always operates correctly on take-off utilizing a Standard Instrument Departure (SID).

There is no particular reason for this - it just happens from time to time.

Understanding V-Nav and what its doing can be challenging

The challenge, I have discovered when using V-Nav is two-fold.  First and foremost, you must use it within the designed capabilities of the program, and second, you must learn how and when to operate V-Nav.  If you enter data that the FMS cannot assimilate, such as an altitude that is too high or too low, for the time required to reach the waypoint, then expect an overfly of the entered restrictions.  This is not the fault of Sim-A.  It's user error. 

Sim-A, in my opinion is not alone with minor V-Nav issues; Project Magenta, Pro Sim 737 and others also have difficulties replicating this complicated algorithm. Indeed, real pilots are often confused understanding how V Nav operates and why it's doing whatever it's doing! 

This is one reason why V-Nav should only be used as a guide and not as an absolute.  If V-Nav, for whatever reason does not function in a method you believe to be correct, then turn it off and use the more reliable L-Nav, Level Change or Vertical Speed functions.

Issue 3 - Display Lag and Staggering

There is minimal display lag running Sim-A and FSX (using two computers). 

The gauge movement of the displays is fluid and there is no pausing as information is shuttled to and from the computer and Sim-A.  However, if “all waypoints” is selected to be displayed on the ND, then staggering becomes obvious on the Main Flight Display’s altitude tape, as the aircraft ascends or descends in altitude. 

I’ve been told by long-term Sim-A users that this is normal as the information required to display and update the “all waypoints” is very comprehensive and can easily generate an “information bottleneck”.  The solution is easy – turn off “all waypoints” when climbing, descending, or on approach.  Honestly, I rarely have "all waypoints" selected and only use this function if I am searching for the nearest waypoint to make an alteration to the flight plan.

I have not experienced any display lag or staggering issues with other EFIS functions. 

Issue 4 - Software Server.exe Lock-up

When you read this title, I can image the thoughts going through your mind.  But, this is one of those negative aspects that has a very positive twist. 

Although the software has never crashed to desktop, it has on occasion “locked up” requiring a reboot of the Sim-A server.exe.  The lock up usually occurs when I have been repeatedly doing something incorrectly, such as keying into the CDU  incorrect information, therefore; the lock-up caused by user error. 

If this issue should occur (for whatever reason), it's only a matter of closing the server.exe using the shutdown command tab and then reopening the server.exe window.  You do not need to close down Sim-A or FSX. 

This brings me to the positive twist I mentioned in the earlier paragraph.

Outstanding Sim-A Feature

Of the many features Sim-A has, the ability to historically re-set the software without loosing your flight details or actual flight (in real time) is probably one of the more beneficial. 

If a problem should transpire during a flight causing the server.exe display to freeze or something to stop working, you can re-set the software by closing the server.exe display and reopening it.  The interruption to your flight will be seamless, providing you depress the tab “last state” within ten seconds of reopening the server.exe display window.

This is but one of several "smart" features that are often overlooked.

sim avionics server user interface

Functionality Controlled by Control Panel

Sim-A’s central access point is the control window (server.exe) which is always visible on your “flight configuration” monitor. 

The server.exe display window is the core of the program and shows the current “avionics” status of your aircraft (EFIS settings, weather, terrain, TCAS settings, aircraft details, engine, hardware settings, etc).  The display also provides a handy central area in which you can tweak the aircraft’s .cfg file, FSUPIC settings, offsets and so forth.   For more detail on this comprehensive display I direct you to the Sim-A website.

The Sim Avionics server user interface is where you can control all of the Sim Avionics variables.  It does look complicated and there is a lot of information on the screen; however, it took me less than 30 minutes to get a rough idea what was happening and get into the air.  Menu tabs open up further screens and all settings are automatically saved on a regular basis. 

Sim Avionics Features

At the minimum, the Sim Avionics avionics suite will display the following:

• Captain and First Officer Primaryt Flight Display (PFD) and Navigation Display (ND)

• EICAS Display (upper & lower) with fully integrated EICAS messaging

• Virtual Main Control Panel (MCP)

• Virtual EFIS Displays (2)

• Virtual overhead panel

• Virtual CDU Display

• Multiple CDU Support

• Support for Hardware MCP & EFIS

• Complex Auto Pilot Functionality (SINGLE CH, LAND 3)

• Sound module

• EGPWS and TCAS

• B737 system logic

• Weather Radar (weather) & Terrain overlay displays

• Virtual stand-by instruments (assorted selection)

• Fuel & scenario loading platform (dispatcher console)

Other functionality, such as instructor station, and observer CDU is available depending upon which license type you purchase.

To see screen grabs of the display functionality of Sim-A (PFD, ND, radar, etc), navigate to the Sim Avionics website.

Of course, if you are operating a full flight deck with the appropriately supported hardware you will not require the virtual MCP, EFIS, CDU and overhead displays.

Support for Add On Hardware, Flight Models & Software Cloning

Speaking of hardware, SIM-A supports many of the popular hardwired instruments available on the market.  For instance, the CP Flight MCP and EFIS units are, with some minor .cfg  file alterations plug & fly.  Similarly, GoFlight and Flight Illusion products are easily configured for Sim-A use.

Currently SIM-A supports the B737 and the B777.  Several B737 and B777 aircraft configuration files (FS9 & FSX versions) are available within the software: default model, PMDG, Posky, Wilco, XPlane and Meljet.

Another feature of Sim-A is the ability to run certain aspects of the software from different computers.  For example, you can clone the sound module to run on different computers, thereby, playing aircraft sounds through one set of speakers, and ATC commands through another set of speakers (or headset).

CDU - Background Software

No review of Sim Avionics would be complete without a short segment on the CDU.

Sim-A is the controlling software that provides the intelligence behind the CDU.  It's amazing what this software can do, and do so with reliability and consistent behaviour. 

Most pages associated with a commercial CDU are modeled and updates continue to add new features and improve on existing functions.  Some of the basic features that are modeled by the software are:

• Indent page on start-up (weights, fuel, cost index, etc)

• Approach reference page with VREF selection

• Route, LEGS, Arrival, Departures & Holding pages (user controlled including approaches, STARS & transitions)

• Progress pages (fuel, distance to go, ETA, wind, crosswind component, cross track error, fuel prediction etc)

• Cabin calls

• METAR (real time)

• V-Nav & L-Nav compliant (climb, cruise and descent)

• GPWS overrides

• NAV radio page (ADF, VOR & ILS data)

• ACARS

• Captain EFIS control

• SIM control page (separate commands to control SIM instead of using keyboard)

To see screen grabs showing the various features available, navigate to the CDU page on the Sim Avionics website.

Further Functionality

I/O Interfacing and FSUPIC is fully supported as are FSUPIC offsets, and if your using an FDS MIP, a program called InterfaceIT provides an interface for connection of switches, lights and other modules to Sim-A. 

Documentation

A manual is supplied with the software and there are several documents (within the documentation section of the main Sim Avionics folder) that assist in the correct set up procedure. It is VITAL that you read all the documentation BEFORE installation. 

For a more in-depth look at how the autopilot functions, see the Autopilot Functional Examples - Sim Avionics booklet. The booklet can be downloaded from the documents section. This document provides an excellent review of MCP procedures in relation to takeoff, descent and landing (ILS & LAND 3).

Software Installation

Installation is uncomplicated.  However, there are a number of changes you need to make to several files to ensure correct operation.   Additionally, if you’re using two computers then basic networking knowledge is required, as are the programs Wide Client FS and a registered copy of FSUIPC.

Determining the correct location for the various avionics displays on the computer monitors (within the MIP) is straightforward, although fine-tuning the location on the monitor can take a little time.  Basically, you alter the length and width of the various displays within the config files.  Once you know how this is done, it's just a matter of altering the line numbers until your satisfied with the result.

When Sim-A is set-up correctly, everything is relatively painless and obvious - more or less “following your nose”.

Running a flight deck isn’t pressing a button and “presto” there it is… 

For the avionics suite to operate correctly, several programs or clones of the program must be loaded.  At the minimum this is:

• Captain's PFD and ND;

• ND, First Officer's PFD and ND;

• CDU Captain;

• EICAS;

• CDU First Officer;

• Server.exe;

• Tcp Client;

• InterfaceIT;

• Wide FS and Sound; and,

• The dispatcher console (if required).

The window displays are opened by clicking the .exe shortcut files. These shortcut menus are installed to your desktop when installing Sim Avionics.

To minimise the time in loading and to be user friendly, a handy program has been included with Sim-A, hidden within the documentation folder; it is a start-up batch file. This program allows to you start all the functions and displays with the click of one button.

I've compiled a short video showing how the program automatically opens and loads the software using the batch file. In my set-up, Sim-A is installed and operates from my second computer (client). 

BELOW: Batch file start of the Sim Avionics software.

BELOW: Various functionality available via the main Sim Avionics display server.exe user interface.

Ownership and Support

Sim Avionics is the preferred avionics suite of Flight Deck Solutions.  If you purchase an integrated MIP from FDS, Sim-A is the flight software that will be supplied. 

Support for Sim-A is provided by the software’s main engineer and FDS staff.  Help can be obtained either via the active support forum (on the FDS website) or via e-mail.

Continual Development & Financial Investment

Sim Avionics is not an inexpensive investment, however, it’s pleasing to see continued development of the software; updates that add or improve on existing functionality are released on a regular basis.  Furthermore, the software designer is open to suggestions from users on how to enhance the software.

At the time of writing, if you purchase Sim Avionics through Flight Deck Solutions then the price of the software includes full support and updates for an unlimited time period. 

Recommendation & Overall Score

Sim Avionics is a stable, well tested and tried software platform that provides most of the real-world avionics of a B737 jet-liner.  The software is easy to install and use, however, advanced knowledge is required to use some of the advanced features such as FSUIPC offsets and the like.  All avionics software has issues from time to time, and Sim-A is no different, but the ongoing development of this software and a solid support structure can only be seen as positive.

To investigate Sim Avionics more closely, visit their website.

My Rating is 8.9/10

• Please note that this review is my opinion only and is not endorsed.

Update

on 2014-12-15 21:31 by FLAPS 2 APPROACH

The Sim Avionics software has been updated to a newer version.  Therefore, the issues mentioned in this review may have been rectified.  I have not used the updated software. 

737-300 Telephone & Microphone for 737-300 Center Pedestal

View fullsize

737-300 internal communications

I have installed to the rear of the center pedestal the correct telephone and microphone for the 737-300 aircraft.  Neither item is necessary, but it adds to aesthetics and fills the empty gap where the telephone should have been installed.  Although the telephone and microphone are functional, they have not been configured to operate with the avionics suite or flight simulator.

The center pedestal and telephone are not from a 737-800 aircraft, nor would they ever be seen on a Next Generation aircraft; they fill a gap until the respective OEM components can be found.

Sometimes it’s a matter of what is available, or waiting until a part becomes available. In this case, I decided to use what was available.

This type of telephone and microphone (as well as other types depending upon manufacture) were used on the 737-300 through to the 737-500 aircraft.

As you can see from the photograph, this telephone has been there and done that!  The telephone is considerably scratched, but I prefer using part that shows service, rather than using a shinny new reproduction item.

Live ATC - Listen to ATC In Real Time

Many virtual aviators are confused when it comes to understanding the language used by air traffic control and pilots.  The three questions often asked are:

• What to say ?

• When to say it ?

• How to say it ?

There are several on-line tutorials available to learn air traffic control and aviation language, however, often a far easier and more interesting method is to actually hear ATC talking to pilots and vice versa.  This in conjunction with a little reading can get you up and flying quickly without making mistakes  when flying on-line.

To listen to live ATC, go to Live ATC, select your airport code and frequency and sit back a listen.  The frequencies are already on the website, so all you need is the ICAO or IATA code of your airport. 

Live ATC can be be listened to either via the web or if your "on the move" and really cannot be without ATC, then your android or i-phone. ATC is a volunteer organization, so expect some adverts on their website.

Flight Testing - The Good, The Bad & The Ugly

lot 737-600 (RHL Images from England, LOT B737, SP-LKF (3833448252), CC BY-SA 2.0)

Flight Testing - Hardware & Flight Models

Now comes the fun and not so fun part - field testing.  Everything has been configured (throttle, MIP, yoke, etc) and requires flight testing to ensure correct operation.  Reliability is related to repeatability; therefore, to ensure reliability you must replicate the outcome several times before you can state something is working correctly.  This takes time and many takeoffs and landings.

As you can imagine, there are many systems that inter-finger to achieve the desired outcome, and all the systems, hardware, software and components must be correctly communicating between themselves to replicate flight.  Often a small problem can develop from something as insignificant as a loose wire or a incompatible computer part.  I've already had a few spanners thrown into the mix with faulty power packs, problematic USB cables and USB ports and a few user problems.

It's during this test period that I hope to iron out any niggle problems to ensure a robust and trouble-free system for the future.

• Flight testing occurs whenever a new component is added, changed, or the avionics software is updated.

Word of Advice - Go Slow & Be Methodical

To determine the solution to any problem that may arise, it's important to know which hardware or software is causing the problem.  When in the test phase, it's best to only have the basic software installed.  When your happy with the result, add another piece of software and test.  This is the best way to build a robust system.  The temptation is to install everything and then field test, only to find an issue and not be able to work out what is causing the problem.  Develop and build in stages, try to take your time, be methodical, take notes and replicate the results before moving on.  It's a slow and often tedious process.

One benefit of going slow is that you will have the opportunity to learn your software and know what it can do and more importantly what it can't do. 

Bugs

Often individuals will state a piece of software has bugs as it doesn't do what they believe it should be doing.  Certainly some software is bug prone and should be avoided, however, for the most part high-end software and hardware more than often operates correctly and is trouble free. 

A piece of software or hardware can only function within the specifications of the, motherboard and other software you have installed.  It is not uncommon for one individual to state a bug whilst another has no issues what-so-ever.  Before crying BUG, it's best to check, double check and then check again.  Often the fault will be your computer set-up or your lack of knowledge to what the software can or cannot do with regard to the computer and computer components you are using.

View fullsize

Examining The Flight Models

Testing also includes evaluating the two flight models that interest me: the PMDG FS9 and default FSX 737.  At the moment I prefer the former; probably because this is the aircraft model I've used since it was release.  Each model has its differences and nuances.

I'll post a separate entry in the Journal outlining my thoughts on the two models in due course, although this is a personal preference.

Unfortunately, the CP Flight MCP PRO I purchased appears to be faulty and have been returned to Italy.  Using the virtual Sim Avionics MCP achieves the same outcome, but it's a bit ungainly using a mouse and separate MCP screen.  Hopefully a replacement MCP will arrive in a few weeks time which will flying easier and more enjoyable.

Testing Duration

To test anything properly requires at least a few weeks; as mentioned above repeatability must occur.

Eye Candy

The outside model, what the Americans call eye candy is not of great importance to me.  Most of the time I like to fly IFR in inclement weather, so looking out the front or at the exterior is not that important; I spend most of my time reading instruments, manuals and looking at charts (yes I like paper charts although I do also have an electronic flight bag).

External Visuals

At the moment, during the initial flight testing stage I am using a rather small computer display; functional when building and testing, but not that exciting to fly with.  Following construction, more suitable external visuals will be looked at.

Update

on 2013-06-17 23:00 by FLAPS 2 APPROACH

Time has been limited, however, I have completed several flights using the two flight models that interested me - the default B737 FSX and the PMDG (FS9 version) B737.  Although both flight models depict the same aircraft, there is considerable variation in how each model behaves. Many of the differences are small and probably would not be noticed by a casual flier who has only experienced one flight model.

Easy to Nit Pick

It's easy to fall into the trap comparing flight models for entirety and nit-pick each to death without coming to a conclusion.  Put simply, it's about compromise.  Each model has its benefits and failings.  After considerable time and effort, I've decided that the PMDG FS9 model is suitable to my style of flying (at the present time).

Main Differences - PMDG FS9 Model & Default FSX 737 Model Using ProSim737

The main differences that I have noted is that the default B737 model, in many respects, is VERY EASY to fly.  Its responsive to flight inputs and generally speaking is not challenging when flying - even in a cross wing.  Some of the methods in which instrumentation interact with the model is also slightly different. For instance, when flying in command mode (auto pilot on), the default B737 will not allow you any roll CWS using the yoke.  You must depress the CWS button on the MCP to allow the aircraft to be rolled whilst the auto pilot is controlling the aircraft.

In contrast, the PMDG FS9 flight model is generally more difficult to fly and control.  Landing in a cross wing requires far more concentration as does a normal take off and climb to altitude.  Interestingly, the CWS issue mentioned above is not a problem with the PMDG model.  If the aircraft is in autopilot mode with command activated and you wish to alter course, all you need do id move the yoke and CWS roll or pitch is activated whilst the auto pilot is maintained.  This has obvious benefits.

A few other variables that I was not happy with when using the default model are;

• Instability in pitch during a VNAV descent

• Instability in pitch when using the speed brake

• Overpowering of engines during take off and climb

• Flaps extension and retraction appears to be very fast

• CWS roll/pitch requires engagement of CWS button & disengagement of auto pilot

• Poor outside visuals (aircraft in spot mode)

Many of the above issues can be easily rectified by editing the constraints in the Air File.

One of the benefits of the default model is it allows connection and configuration to any of the standard FSX controls (aircraft lighting, various buttons, etc).  It's unfortunate that the same level of interaction is not possible when using the PMDG model (without further configuration & work around).  As an example, the navigation and strobe lights cannot easily be connected to an outside switch using PMDG.  This is because PMDG has configured their model outside the standard defaults of FSX.

I have no doubt that there are other nuisances that I've yet to discover. 

Which Flight Model - PMDG FS9...

Personally I prefer the PMDG FS9 model as it delivers greater flight accuracy than the default model.  For this reason I will most likely use the PMDG as a standard model.  This said, once some tweaks are made to the default model's Air File to counter the above mentioned dot points, the model flies quite well with full button capability.  However the CWS roll & pitch discrepancy, for me, places the PMDG FS9 model ahead of the default model.

Update

on 2012-06-20 03:30 by FLAPS 2 APPROACH

After spending the last few months on and off flight testing, I thought I'd share my final decision to which flight model the simulator will be using. 

ProSim 737 and JetStream B738

I spent May and June field tested ProSim 737 as an alternative to Sim Avionics.  ProSim737 can be used with a number of add on aircraft, however, they also produce a dedicated flight model to the their own software called the JetStream Advanced Flight Model B738.

I'm impressed  with the JetStream and believe it to be the par of the PMDG FS9 model.  Certainly, the external visuals do not match PMDG, but this is not the concept behind the JetStream.  The concept ProSim wanted to deliver was an aircraft model that provided a top shelf flight model compatible with ProSim's flight avionics suite.  As such, external visuals are as per the default FSX 737.

I'll be compiling and posting to the journal section  an evaluation of the JetStream shortly.

• The avionics suite chosen is ProSim737 and the flight model is the JetStream 738 (as at June 2012).

Never Do This - Changing Voltage Will Destroy Your Computer

View fullsize

Friedrich Haag, 003 2018 05 14 Dunkelheit, CC BY-SA 4.0

I am using two computers networked.  I was doing some tests in an attempt to separate the sound between the two computers so I can utilize a headset when I heard a horrible grating noise coming from one of the computers.  I've heard the sound before so knew what it was; one of the fans was either failing or required lubricant in the bearing.  A little odd considering both computer are less than 3 months old.

Variable Fan Switch

The computer has a variable fan switch on the rear toward the power cord.  I lent down behind the MIP to either turn the switch to low or off in the hope of isolating the fan noise.  As I selected the switch I heard "BLIP" and the computer stopped.  I closed the other computer down, found a torch (flashlight) and peered behind the computer console.  I saw the switch, but to my horror I also saw another switch.  Sliding the computer out from behind the MIP I authenticated what I had thought.  Instead of switching the variable fan switch I has tripped the switch that changes the computer from 240 volt to 110 volt.  Both switches reside almost side by side.

Voltage

Never change a voltage switch on the rear of the a computer from your countries voltage requirement.  Depending upon which direction you move the switch and what voltage you are current on, will indicate the resultant effect.  240 V - 110 V "blip"!  110 V to 240 V "BANG" with everything "fried" beyond repair.

In some respects I was lucky, I only "fried" my power source.  A replacement was relatively easy  and I had a IT friend check the computer to ensure there were no other issues.  Oh - and the noisy fan was isolated and replaced.  It was the fan on one of the video cards (there are three video cards.  The video card was replaced under warranty.

Advice For The Future

Use a piece of tape to cover the switch so it cannot be inadvertently tripped.