[NSRCA-discussion] Ideas on radio beserkness-cause of crash??

[Gray E Fowler]

Guys

Yesterday on my 4th flight of the day my PCM Stylus went nuts. PCM program 
was set for idle throttle and about 5-6 clicks(trim wise) of up 
elevator-all other surfaces neutral, and this was tested as such by 
turning off the transmitter.  As I passed by center I noticed that I could 
not gain altitude and the the throttle started going from idle to 
high...then ailerons started oscillating small left-right deflections. I 
cut the throttle to the kill position but the engine persisted up-down 
bursts. I was able to do a 180 degree turn with aileron coming back to 
center...never losing altitude, but unable to change the altitude,elevator 
seemed unresponsive. As I passed by center again I was losing more and 
more control. The plane flew over the wooded area south of the field at 
about 200 feet high, I could not turn and the ailerons rolled the plane 
upside down and it went straight down into the trees. This whole episode 
last about 45 seconds. Cannot find the plane, and remnants of Gustav are 
headed my way.


Plane was new had about 10 flights on it.

New battery..NiMH 5 cell pack -no regulator (ran 5 cell packs for years, 
no regulator) 
Reciever-1999 Stylus PCM-never crashed, wrapped in foam
New switch
Transmitter-1999 Stylus, never been serviced, never had problems

What would cause a PCM receiver to do such a thing? If I had and 
intermittent signal, once the receiver did get a signal the only two 
throttle signals should have been idle (PCM hold) and off (transmitter). I 
am going to send the transmitter in just to get checked.

Thanks guys....


Gray Fowler
Senior Principal Chemical Engineer
Radomes and Specialty Apertures
Technical Staff Composites Engineering
Raytheon
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