All, I sent this email to Steve and Wolfgang off-line with names. I deleted the vendor name and post this response to the request. I will respond to each email if requested.
Steve and Wolfgang,
It was xxxxxxx xxxxxxx. I sent the autotrim module back and they repaired it with no questions and no problems. I never knew why it ran off, I just know that they repaired it and sent it back.
FYI, I had another problem with the vertical servo which went back and forth for about a year and a half. The auto pilot would not hold altitude. I played with parameters and pin-out for almost two years. Each time I dealt with a technician, I felt they poo-pooed my concerns and got the sense that they viewed my issues as psychosomatic. On multiple occasions I sent components back and was told that nothing was wrong. Finally I pulled everything out and sent it to them. All servos, autotrim unit, the main unit and requested a bench test and asked them to find the problem. They told me that there would be a $50 dollar charge for diagnosis if the problem was not a factory problem. They diagnosed the issue and finally repaired the vertical servo. They were reticent to tell me details. Finally I told them, look, I'm not a lawyer and I'm not trying to build a case against you. I told'em I'm a Mechanical Engineer and I just want to know the root cause. Finally they told me that there is a spring inside the vertical servo that was not calibrated and/or installed correctly. They fixed the issue at no charge and I've been flying wonderfully ever since.
After the repair, my comfort level with the plane went through the roof. Even with all the problems I am pleased with xxxxxxx. Like I said, I'm a mechanical engineer and have been involved in a lot of new equipment installations, and I've never had a new install without problems and most of the time most technicians give a "quick" diagnosis if they've never seen a scenario. I think my case was a rare one and that's why, in my mind, I had soooo much trouble.
The issue would exacerbate when the Garmin 430W would go into approach mode. When that happened the vertical steering would get extremely unstable. Oscillations about the set point would amplify on the Garmin 430W. When the system was switched to the Chelton, the damn plane would nose dive to the ground.
Hope this helps. if you have any other questions, give me a shout. Steve, you were gracious enough to phone me two years ago about oil on the belly and I really appreciated that. Oh yea, that issue turned out the be a cracked oil cooler that got progressively worse until finally it failed catastrophically--I landed with 3 quarts of oil in the sump--but that's anouther story.
Abe Gaskins
MGM Industries
Office 800-476-5584
Direct line 615-265-2046
Cell 615-642-2310
www.mgmindustries.com
http://www.youtube.com/user/mgmindustriesinc
On Sun, May 30, 2010 at 2:25 PM, Steve Colwell <mcmess1919@yahoo.com> wrote:
Abe,
I would like to know what component failed. Manufacturers
don’t like the bad press or the threat of liability but we are potentially
the most injured parties. Please reconsider posting the failed component
on LML for others benefit. I will not post your response to me on the
internet.
Steve
It was a faultly unit from the factory. I hesitate the name
the factory on the list because it could cause tempers to flair and I would
like to avoid that. I will respond directly or by phone. I sent the
unit back and it was sent back no charge and I have not had a problem
since.
My autotrim did not have a disconnect switch so the only was
to disconnect the autotrim was to disconnect the autopilot or pull the breaker
on the autopilot. I would advise to be able to have a discrete switch to
disable the autotrim and not the autopilot. If I was IMC when my event
happened without a means to disable the autotrim, I wonder what the result
would have been.
On Sun, May 30, 2010 at 12:09 AM, Steve Colwell <mcmess1919@yahoo.com> wrote:
Abe,
What caused the Trim Runaway?
Steve Colwell
I
had an incident one time. I had a run away condition while at
cruise altitude and I really had to fight the forces. I was not as adept
to the system as Josh, but did manage to control the plane. I would like
to mention when I prepared for landing I obviously had to slow the plane down.
When I pulled the power back the stick forces got much more manageable.
On the ground, or in hindsight, you'd say:"gesh, dumby--that's
obvious." Thinking isn't quite so fluid when it's happening. So a
thought, if it happens and you forget to pull the breaker, put pulling
the power back in the ditty bag of tricks.
|