"John Schroeder" <jschroeder@perigee.net> wrote:

"""
We have the PTT/mic button on the trigger switch, roll and pitch trim on the
coolie hat and the roll steering/auto pilot quick disconnect button on the top
button where the thumb can get to it easily. ...snip... If I were to do it again, I
would swap the PTT with the AP roll steering. Pushing and holding a button is
far more correlated with everyone's experience handling radios.
"""
When we did the Infinties in Ted Noel's IVP we spent lots of time talking to people about what they included on their grips and why, talked to the folks who make the grip, and noodled logical arguments about all that input back and forth until we came up with what seemed the most reasonble.  We decided to take your "If I were to do it again" approach by putting the PTT on the thumb button (very easy, relaxed access that doesn't induce stick movement) and A/P disconnect/roll steering on the trigger.  The logic was that the tactile feedback from the grip required to squeeze the trigger really lets you know that you're holding the stick, which is what you want when you wrest control from the A/P.  We also chose to do pitch & yaw trim on the coolie hat with roll trim on the switch next to it.  Again, logically because changes in pitch typically accompany power changes, and power changes usually necessitate yaw trim adjustments, thus the 2 go together.  Pushing the  toggle next to the coolie hat from side to side mirrors what you want to do in roll... push the switch to the left to push down the left wing and vice versa...again a logically driven positioning.   These locations undoubtedly fly in the face of convention, and if we find anything that doesn't bear itself out in flight it's easy enough to swap some pins and move things around. 

There are trim-disconnects on each side of the panel to allow trim control from either stick individually or both. 

Ted's remaining 2 buttons control the Chelton screens... one to step through the EFIS displays, the other to step through the EAU displays.

    <Marv>

PS.. if we had quad 50's in the wings or a 20mm cannon running the length of the fuselage, we probably would have used the trigger switch differently.