Hartmut,
Understood. It will be on the Emergency Practice list, rather than
Emergency Checklist.
Linda
1b. Re: control system flutter
Posted by: "Hartmut Beil" [email protected] hbeil
Date: Fri Apr 17, 2009 11:57 pm ((PDT))
Linda.
Although it might be good to add "how to response to flutter" on your
emergency list, it won't help you in the event of flutter.
I experienced aileron flutter myself that started at around 90 miles
and went away with 110 miles indicated.
That flutter came sudden and with brutal force it seemed. It was like
someone hammered at my right wing with a high frequency.
I could not see the aileron flutter, but I could feel it through the
controls. So I steered against it and for that moment the flutter was
gone. Since you canT hold that steering in a right turn forever, I
steered to the other side, and got the onset of flutter in-between.
So I zig-zaged for a moment through the air until I reduced my speed
below 90 and the flutter would not occur.
However, the message here is; Flutter is coming instantly and with
brutal force over you. No time for checklists or any thinking or
doubts. You need to put load onto the fluttering surface to mitigate
the flutter. It might not completely disappear, but it's force can be
reduced.
Second step is to reduce flying speed. Then land ASAP.
The cause for my aileron flutter was a worn outer aileron hinge. In
the post-flight inspection one could not see the amount of wear, even
when moving the aileron up and down on it's trailing edge. You could
though apply forces direct at the hinge and see extra movement.
Replaced the hinge and all was fine. I now do test the hinges more
carefully at pre-flight. At the outer hinges I apply up and down
forces directly to the aileron at the hinge area.
Same for elevator and rudders, worn hinges are cheap to replace. I
guess, i'll add this to the articles about control system care:
http://www.ercoupe.info/?n=Main.Controls
Hartmut
