Originally Posted by
grognard
Hands up all those who fly IC powered models who think this is reasonable. For my money, putting a spring of any kind in opposition to a servo is generally bad practice. In this specific case, the spring will have to be strong enough to overcome the resistance of the servo with power off in order to close the throttle. No I don't have numbers but those of us who set up our own control systems know that it takes a few ounces to get the servo moving. So the servo will be fighting the spring all through each and every flight, drawing more current, running the battery down faster, and shortening the life of the servo.
Knee jerk solutions imposed by bureaucrats on the spur of the moment are rarely well thought out.
The wonderful thing is that I don't have to design YOUR system. You do, as you're the one who's obligated to "
ensure that the small unmanned aircraft will pose no undue hazard to other people, other aircraft, or other property in the event of a loss of control of the aircraft for any reason (emphasis added)."
So add redundant wiring, or batteries, or receivers, or all of them. You decide. And if something happens, you'll get your chance to tell investigators or litigators or a jury that what you decided was more than adequate - that 'accidents happen.'