User Manual

A MIXER TO ELIMINATE PITCH-COUPLING
This Multi-Point Program Mix is intended for aircraft that pitch towards the landing gear when holding
rudder for knife-edge flight – commonly known as Pitch-Coupling. If a mix is set up to provide an
appropriate amount of Up elevator for different amounts of rudder input, the aircraft will fly straight
without pitching to the gear while holding rudder during knife-edge flight.
This mixer uses the Rudder as the Master and the Elevator as the Slave. The mix is turned on and off
with the GEAR switch
1. Select an unused Multi-Point Program Mixer (PROG MIX1 or 2)
2. Select RUDD as the Master and Select ELEV as the Slave.
3. Highlight & select SW SWLECT and then select GER as the switch to turn the mixer on & off.
4. Set The Points to the following values:
Point-0 -10% (At Full Right Rudder the Elevator will deflect UP 10%).
Point-1 INH (Takes on value between Point-0 and Point-2).
Point-2 -3% (Elevator deflects upward 3% when Rudder is moved to point-2).
Point-3 0% (No-mixing – this is the Offset position and must remain at 0%).
Point-4 -3% (Elevator deflects upward 3% when Rudder is moved to point-4).
Point-5 INH (Takes on value between Point-4 and Point-6).
Point-6 -10% (at Full Left Rudder the Elevator will deflect UP 10%).
5. Verify Operation. Turn the RX on and turn the mix on using the Gear switch. Move the
rudder stick from full right to full left. The elevator should deflect Up when the rudder is
moved in both directions. If it moves down instead, change the percentages to + values instead
of (-) values at each point. If the elevator appears to be moving too much, reduce the point
values (less negative). If the elevator does not seem to move enough then increase the point
values (more negative). Now turn the Gear switch to the OFF position and verify that the
elevator does not move when the rudder stick is deflected.
While test flying the aircraft make note of the mixing and whether it is generating enough up-
elevator during knife-edge to stop it from pitching to the gear, or generating too much elevator
input causing it to pitch to the canopy instead of the gear. Also note the approximate position of
the rudder stick when pitching occurs. Land the aircraft and adjust the points closest to the
position of the rudder stick when pitching occurs for more or less elevator deflection until the
aircraft no longer pitches during knife-edge. More negative typically generates more Up elevator
and less negative generates less Up elevator. Points 1 and 5 may be activated and their value
changed if necessary to fine-tune the mix.
9303 Program Mix Examples 8