Weber — Articles / Posts — Flaps 2 Approach

oem 737-500 weber claw feet and platform mount

The Main Instrument Panel (MIP) is an integral part of the flight deck. Now that it is installed, other components can be measured and fitted to the floor platform. I wanted to install the eats correctly, even though the platform is a interim platform and will be replaced with an aluminum box platform sometime in the future,

The two Weber seats would take considerable time to attach to the platform, as unlike Ipeco seats they do not use a J-Rail system, but use claw feet. The feet must be positioned correctly onto the platform floor.

Attachment Stress

In my earlier posts, I mentioned that to manipulate the various levers which move the seats results in relatively large amount of stress being placed on the attachment points of the seat to the platform floor; there is reason Weber seats have 16 attachment points to the flightdeck floor.

To minimise the chance of the seat moving when adjusted, I fabricated a mount that sits beneath each seat. The mount, constructed from wood, is 16 mm in thickness and is bolted to the 16 mm thick platform floor (36 mm total thickness). Rather than use wood screws to attach the seats, I decided to use 55 mm length bolts with washers; my thinking is that the bolts will provide far stronger attachment points, when installed through the seat mounts and platform floor, than wood screws.

Attaching the Seats

The first task was to cut and paint the seat mounts which was straightforward. Each seat was then attached to its mounting base and then secured to the platform in the correct position with bolts. The biggest problem was actually lifting and moving each seat into position on the platform, each seat and segment of flooring weighs over 50 kg.

Correct Positioning

The correct positioning of the seat and seat mount is very important. Boeing specification states that the distance from the front of the seat to the MIP is 340 mm, however, this depends on where you are measuring to and what type of MIP you are using. The measurement if using a FDS MIP is from the front of the claw feet to the forward edge of the lower kickstand. This measurement is 440 cm.

wooden platform mount connected to claw feet of weber seat. the seat and mount are them positioned correctly on the platform and secured using bolts

The seats move forward and aft, by pivoting over the secured claw feet (see video); therefore, if the measurement is out by a cm or so it is not really an issue as the seat movement can take up the difference.

It Works….

With the platform floor secured to the base it was time to trial the seats. Both seats work well and there is no movement or flexing at their attachment points. There is also no movement where the seat mounts join the platform floor.

I think it was overboard using 16 bolts and bolting through 36 mm of woo! But, I wanted to make sure the seats did not move on their base as I didn't particularly want to remove them and start over again.

Additional photographs of the Weber seats.

Next on the list is installing the ACE yoke and throttle quadrant.

The wooden platform has since been replaced with a modular aluminum structure.

Modular Aluminum Floor Platform.

The under seat workings of the Weber seat: Heavy duty chassis, the smaller of two heavy duty springs, two of three cables and the cylindrical hydraulic/pneumatic cylinder

In a earlier journal post (Weber Captain & First Officer Pilot Seats), I discussed the purchase of two Weber pilot seats. What I didn’t discuss was how these seats function. Weber seats, although constructed from aircraft rated aluminium are not light in weight; each seat weighs approximately 40 kilograms. Most of the weight is associated with the robustly constructed underside the seat.

The seat has four movements:

Forward and aft movement;
Vertical rise;
Recline of back rest; and,
Under leg rise & fall.

Mechanics

Each movement is initiated by moving one of three solid lever on the pedestal side of the seat. The lever operates a push style button connected to the end of a cable. As the lever is moved the button is pressed or released with a corresponding press and release from another button at the opposite end of the cable. The compression needed to allow these movements is controlled is by a very heavily constructed tensile spring that is contained within a cylinder. This in turn is connected to a hydraulic/pneumatic piston that allows for greater ease in movement.

The mechanics control the subtle movement of the rear seat recline (like in an automobile) and the under leg rise and fall of the portion of the seat, that can be raised under the calves to allow more or less reach to the rudder pedals. When the desired position is reached and the lever released, a heavy duty ratchet / cog is engaged locking the position in place.

The two most aggressive movements of the seat are the forward and aft movement of the seat and the vertical rise. This and the non use of J rails are two reasons that Weber Seats are attached to the flightdeck floor by 16 attachment bolt points by eight claw feet (duck feet) for each seat.

Weber manufactures a number of different variants: hydraulic, electric, spring or a combination thereof – there are several variations in use throughout aircraft fleets. The seats I am using are spring and hydraulic controlled.