Sender: <marv@lancaironline.net> (Marvin Kaye)
To: lml
Date: Fri, 08 Nov 2002 14:09:52 -0500
Message-ID: <redirect-1856398@logan.com>
From: John Schroeder <jschroeder@perigee.net>
MIME-Version: 1.0
Subject: Re: [LML] Re: STEC autopilot experience -- Jeff
References: <list-1856015@logan.com>
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Hey folks -

Here is why our Lancair ES will have a quick disconnect system for the
autopilot. The spurious inputs/malfunctioning of this equipment is never
something you ever want to experience - as some have related on this
thread.

I was on a weapons run (toss-bomb) at the Air Forces Europe range in
Libya back in the early 60's. Altitude was 500 feet and speed was 600
knots calibrated. The stab aug system was tied into the autopilot on the
F-105D and chose to put a pitch-up command into the system. You can
imagine the results. Airplane held together, but had we been flying with
wing tanks, the damage would have been severe. Can't remember the G's,
but it was close to max. The cutoff switch for the system was a long
paddle switch on the front of the stick that was reachable and could be
actuated with one's little finger. It still takes time to react and do
it, so make sure the cutoff is simple, accessible and kills all the
power to the system until you choose to trouble shoot it on the ground.

Cheers,

John Schroeder

PS: This was a real problem for the fleet and was traced to a cannon
plug in the aft section of the fuselage that was not spec'd properly as
to type, orientation or potting. It rained a lot in Germany and the
water would enter through the split line , run down the wiring and into
the plugs. After this fix was made, there was one other incident where
the culprit was a small solder drop that had shorted pins in that very
plug.

Marvin Kaye wrote:
> 
> Posted for Don Skeele <dpske@wvi.com>:
>      I had a "Hard up" command from my STec Controller while IMC climbing
> out of Camarillo, CA (Which subsequently was determined to be caused by my
> radio transmission being picked up by the adjacent STec wiring in the control
> stick)..This happened at near 5000 ft., the A/C dropped a wing and tried to go
> inverted, I applied hard opposite rudder , pulled power to idle,  stopped
>   rotation and at about 1900 ft. pulled out into VFR conditions, abet sweaty
> palms..  I thank the CFI  John B. who took me through spin training years ago
> in a T-34 over Lake Mathews, CA.. If your still out there, John, God Bless...
>     Needless to say, the wiring has been changed..   Don Skeele 235/320 N320J
> 
> >Interesting experiences. I am wondering if anyone has had an STEC system that
> >rolled into a bank angle and went to the stops? There was a fellow in
> 
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