RS-15 N5724
Flap and Gear Actuation Systems
by
Doug Hoffman

The flap actuator rod was changed to use a screw gear drive instead of rack-and pinion. It takes 4.5 turns of the crank to go from 0 degrees to 45 degrees flap. 8.5 turns to go from zero to 90 degrees. There is enough natural internal friction in the system so that any flap position is maintained without having to install detents or hold onto the handle. Just set it and let go of the handle. It is "infinitely" adjustable.

The position of the flaps can be easily read from the pointer needle attached to the actuator rod.

The gear retraction mechanism which is a simple rack and pinion with a spring loaded detent keeper. You know you are all the way up or down with the landing gear when you hear and feel a very pronounced "click". In this photo the gear is locked in the fully up position.

This picture shows the action required to release the keeper, from either the fully up or fully down positions, so the gear can be raised/lowered. Both cranks are located high and out of the way. Interference with one's legs is not likely.