|Object Name:||Passive Stick|
|Year of Manufacture:||1987|
|Location:||Archive Object Store|
Side Stick Transducer Assy
The YF-22 Advanced Tactical Fighter (ATF) had a side mounted pilot control stick. The amplitude of the pilot's stick inputs are electrically measured and generated as control signals to the aircraft flight control computer. A complex spring/damper system, provides the pilot with force feel characteristics and ensures that the stick is reset to its neutral position without noteworthy overshoots when released by the pilot.
The stick has two-axes and provides both pitch and roll electrical command signals. Typically, four independent electrical pick-offs are provided for each axis of control in order to meet the failure survival requirements. The damper provides a smooth feel to the stick movement the spring and damper combination acting as a low pass filter on the stick movement. A small breakout force is required to displace the stick from the central position in pitch and roll. Roll control is a simple linear spring characteristic, Pitch, however requires a step increase in force at larger stick aft deflections and the spring rate is also increased so that larger forces have to be exerted when commanding high 'g' manoeuvres. A derivative of this unit was designed for the F-22 Raptor and went into the production aircraft.