Per,

If you would rather not use a channel at all, you could use one of the new Autochute units. I'm finishing the Beta testing on the unit and should have it available next month. http://www.details4scale.com/auto_dr...ute_system.htm
The unit uses 2 micro servos. one for the chute deployment and one for the release from the aircraft. The unit plugs into a "Y" on the brake and flap channels. A sensor mounts to any wheel to give the unit real time ground speed. I'll be uploading photos of the unit this weekend to the website.

Dan