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

[Dave Harmon]

Here is what caused me a lot of trouble. I didn't crash but I should have.
The wire broke inside of the insulation so I couldn't see the break.

I pulled on the wires and the insulation came away exposing the break.

My airplane was doing the same thing as Grey's because the receiver was
losing power and then regaining it causing the servos to freewheel and then
jerk back to follow the sticks.

Of course the failsafe didn't work without power...

Not good.

 



 

Regards

Dave Harmon
NSRCA 586
K6XYZ[at]sbcglobal[dot]net
Sperry, Ok. 

-----Original Message-----
From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of Gray E Fowler
Sent: Tuesday, September 02, 2008 8:30 AM
To: NSRCA-discussion at lists.nsrca.org
Subject: [NSRCA-discussion] Ideas on radio beserkness-cause of crash??

 


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 

 

__________ Information from ESET NOD32 Antivirus, version of virus signature
database 3407 (20080902) __________

 

The message was checked by ESET NOD32 Antivirus.

 

http://www.eset.com

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.nsrca.org/pipermail/nsrca-discussion/attachments/20080902/3b36b912/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: image/jpeg
Size: 10517 bytes
Desc: not available
URL: <http://lists.nsrca.org/pipermail/nsrca-discussion/attachments/20080902/3b36b912/attachment-0001.jpe>