OEM Trip Reminder Indicator
/Trip Reminder Indicator. A small OEM part that is easily installed to any simulator
The trip reminder indicator (TRI) is a mechanical device installed to the right hand side of the yoke; it’s an airline option. Basically, the device is three separate digits that can be rotated in any combination, from zero to nine.
The trip indicator is a memory device from which the crew historically used to record the flight number; the pilot uses his thumb to move the three digits to indicate the flight number. However, over time flight numbers became longer than three digits and the use of the trip indicator, for it’s intended purpose, wanned
I use the trip indicator to dial in the Vref, as it’s often easier to quickly glance at the trip indicator to remind you of the Vref speed rather than look at the PFD or CDU. Some dial in the Vref + wind speed.
Background
The trip indicator has a very long lineage beginning with the Boeing 707 aircraft. The device was then ported to the 717, 727 and finally the 737 Classic and Next Generation airframes.
Installation and Backlighting
Because the OEM yoke already has the correctly shaped hole, installation of the trip indicator is straightforward. If you are using an OEM yoke, you probably will need to carefully remove the blanking cover from the hole.
If a reproduction yoke is used, and the hole is not present, a circular hole will need to be cut from aluminium or plastic to enable the trip indicator to fit snugly into the yoke. As the three dials are mechanical, there is no requirement to connect the device to an interface card.
Each of the digits on the indicator is backlit by a 5 volt incandescent aircraft bulb.
The design of the trip indicator is ingenious, in that after the trip indicator has been removed from the yoke (two screws at the front of the yoke secure the indicator), a transparent acrylic slide can be unlocked to slide laterally from behind the three digits (see picture). The acrylic slide accommodates three 5 volt bulbs, each in its own compartment.
To enable the backlighting to function requires two wires (positive & negative/common) to be connected to the appropriate connection on the rear of the trip indicator, and then to a 5 volt power supply. The amperage draw from the three bulbs is minimal. The wiring should be run through the yoke and down the control column so that it comes out at the bottom of the column.
In the aircraft, the backlighting for the trip indicator is connected to the panel light knob located on the center pedestal. This enables the backlighting on the trip indicator to be turned on and off or dimmed.
Final Call
The trip reminder indicator is but a small and unobtrusive item, however, it’s often the small things which add considerable immersion and enjoyment when using the simulator. The trip indicator is also an OEM part that can be very easily installed to a reproduction yoke with minimal experience in fabrication and wiring.
Glossary
OEM - Original Equipment Manufacture.
