Ignition Systems and Interference

The biggest challenge that all of us gas guys face is ensuring that our planes fly interference free.
The First, Foremost and BIGGEST reason is Safety. The far distant second reason is the cost of replacing that beautiful bird. Oh, did I say mention SAFETY!!

RFI - Radio Frequency Interference - will be evident immediately if using a PPM receiver. Do not fly until you obtain excellent engine running range checks with a PPM receiver. Using a PCM receiver for initial range checks frequently masks some RF issues which can later push through the ability of a PCM receiver to filter them out. A crash comes almost immediately after that happens.

So the key is using a PPM receiver for those first critical system checks, not a PCM receiver. Engine off to establish a baseline, then engine running. You want no worse than a 10% difference between engine off and engine running range checks. Over 90 to 100' for a minimum distance, engine running. If you do everything right and have problems do not fly until EVERYTHING is working properly.

What about the 2.4 GHz frequencies that are quickly overtaking the 72 MHz market? You have probably heard that using the 2.4 GHz radios will eliminate you concerns. Right? In fact, it is absolutely incorrect to assume that is the case.

You keep believing that and you're sure to lose a plane. You won't be alone. Others have already gone before you with the same belief. Where the receiver is mounted is not nearly as critical as assuring that you don't have RF issues at all. I've been mounting radio components in close proximity to ignition systems for many years but what has permitted that to work every time is using good components in great condition and making all the checks to assure that any issues were eliminated prior to flight.

Using 2.4 GHz radio does not eliminate RFI, and the 2.4 GHz systems are still subject to various forms of jamming. If one has failed to achieve adequate range checks with the engine off and the engine running the loss of an aircraft is only a matter of time. Using 2.4 will not eliminate that problem, nor will PCM. Both only reduce the chance of a crash from ignition RFI, with 2.4 being better than 72 MHz PCM.

Never rule out anything when it comes to airplanes.

Click here - The ZRCGF website contains further information and checklists to use in finding these potentially unsafe RFI problems.