RE: PPM, PCM ?
i'll start by saying that I agree 100% with everything that Stig posted. His post deserves to be read over and over. I have a gas engine background so I will comment on the idea that an airplane should be set up to with ppm and then go pcm. there might be a few guys that do this, but it really is a waste of time. one of the posts mentioned spurious noise from various sources, and how pcm ignores it and ppm results in a glitch. so imagine i have a 40% airplane with a ppm receiver, and I am doing all sorts of tests and the engine ignition creates this spurious noise - which some of them do. there will be occassional glitches, and one can spend a very very long time trying to isolate the problem. Which is why very few even bother. Start with PCM and the receiver ignores the noise, because as Stig pointed out, the noise isn't sustained. The "masking" argument is not new, but it falls on deaf ears. If you walk up and down the line at an imac event, and have this dicussion, you would be hard pressed to find anyone who start with ppm and goes to pcm. you start wtih th equipment you will be flying.
neither system is going to prevent a crash once the gods align themselves for that to happen. i would never fly a jet on ppm. as much as i would hate to see mine heading for the ground, if the interference is strong enough to cause a fail safe, safety, not the well being of my aircraft, is my first priority.
Paul