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

[Jerry Stebbins]

Gray, hope you can find all the parts, especially if Ike is also coming along behind Gustav.  Sounds like a flight pack problem--bad cell.
I just purchased several NiMH  (1200mah) batteries to replace old stuff as am getting back to flying. My past experience with them is they need 3 or more cycles of slow charge to come up to capacity. Here's what I found:
#1set-slow charge-Airtronics Rx. charger-(36 hours)667mah, again 721mah, again 750mah, again 850mah, I have since put 6 cycles using a Sirius charger and now am at 906mah.
#2-same approach 969mah, again 975 mah, again 1030mah, again 1085mah. after four cycles on the Sirius charger it is 1115mah.
#3 same approach 1064mah,again 1167mah,again1235mah. Then three cycles with the Sirius charger and holding from 1215mah to 1238mah.
I stll have 2 to go.
I am discharging using a Sirius discharger-set to 4 cells, and discharge at 250ma. I tried set1 at 500ma rate and got a drop back to 724 (@ 200 mah). I found little difference between the 125ma and the 250ma rate.
This is also consistent with past experience (6 years ago) with 4 sets (different mfg.)where I never got 1 out of the 4 over 3/4  capacity.
Makes me think seriously about going back to nicads where weight doesn't matter.
By the way these are not el-cheapo brand cells.
Jerry
----- Original Message ----- 
  From: Gray E Fowler 
  To: NSRCA-discussion at lists.nsrca.org 
  Sent: Tuesday, September 02, 2008 8:30 AM
  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


------------------------------------------------------------------------------


  _______________________________________________
  NSRCA-discussion mailing list
  NSRCA-discussion at lists.nsrca.org
  http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.nsrca.org/pipermail/nsrca-discussion/attachments/20080902/0458241e/attachment.html>