Hi Paul,

I am phyically handicapped myself, and earlier in my life I was well acquainted with dozens of SCI folks. I know a little bit about power wheelchairs.

The rudder (or ailerons) and elevator of a 3-channel R/C plane are controlled with push-pull and left-right movements of a single stick. The required movements are sometimes very small, which is why fine motor control is a valid concern. The controls of an R/C plane are proportional, meaning that farther you move the stick, the farther the control surfaces on the aircraft move.

So for example, if the plane is in level flight and you push the stick forward by a small amount, the elevator will move down slightly, and the plane will gently descend. However, if you push the stick forward by a large amount, the elevator will move down much farther, and the plane will go into a steep dive. Most of the time, only small control movements are desireable, hence the need for fine control of the stick.

The point is that the controls of a R/C plane are proportional. They are not an all-or-nothing, on-or-off type of control. Very often, you need to move the end of the stick only a fraction of an inch.

It occurs to me that if you lengthened the control stick of a standard R/C transmitter quite a bit, larger movements of the stick could be tolerated. Much depends on how precisely you can move your arm.

The third control on a 3-channel plane is the throttle. If you can use your other arm, it should be possible to operate a modified throttle stick with that arm. Moving up in complexity, it should be possible to engineer a throttle controlled by a sip-and-puff system. That's way beyond my knowledge, but I am sure it could be done.

It will be interesting to see what you learn from the fellow in New Zealand.

- Jeff