From: CavittP@aol.com
Message-ID: <d85125f9.3607bfbd@aol.com>
Date: Tue, 22 Sep 1998 11:18:21 EDT
To: lancair.list@olsusa.com
Subject: Flap motor proximity switches
Mime-Version: 1.0

          <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>>
          <<  Lancair Builders' Mail List  >>
          <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> 
>>
Last week after takeoff in my L-235/320, I retracted my flaps and when I
released the switch as they reached their normal reflexed and proper position,
they kept coming up and up.  When the actuator reached it's maximum travel the
circrit breaker poped.  

Boy!  Was there ever some interesting aerodynamic stuff happening.  Just like
3/4 span spoilers - pitch up and lots of sink!  Fortunately I was able to
reset the circuit breaker and drop the flaps down to their normal position.

The rest of the flight was uneventful, but am still not quite sure what the
culprit was - the magnetic flap travel proximity switch or the relay?  

I've since put in a hard stop on the end of the flap motor actuator using a
phenolic block that will prevent the reflexing of the flaps beyond the limit
of 1 3/4" reflex, but I think I'm going to have to visit Jim Frantz and have a
look at his limit switches and diode set up.

A few years ago there was a local L-235 that had an incident where the flap
motor actuator "unscrewed" out the end and caused some structural damage to
the seat back...  Don't quite remember all the guy said happened, but my
impression was that it was "bad."

Pete Cavitt - N320PL
619-283-7473