I saw a similar effect where both flaps did not contact their UP stops
simultaneously while setting up the flap drive mechanism. I noted that the up
stop on the flaps seems to be contact of the bottom LE of the flap with the
lower edge of the closeout and is quite positive. Also, the flap drive pushrod
provides some spring action by virtue of its peculiar shape.
By adjusting the UP position of the pushrod so that it springs a bit, both
flaps can be forced to their respective stops. This may require that the
travel be increased slightly when drilling FL21 to accommodate the additional
travel at the UP position while providing sufficient travel to reach 26
degrees at the DOWN position.
It is unclear whether this fiddling is necessary since air pressure should
tend to force the flaps into the UP stop when flying. It's also unclear
whether contact between the flap and the closeout is the intended stop - the
manual doesn't mention this - or if this will eventually mar the paint on the
flap. I intend to put a thin film of silicone rubber on the closeout after
painting to avoid chipping. My guess is that attempting to position the flaps
just off the stop using the pushrod will actually lead to chipping of the
paint from vibration in flight.
The DOWN position is less positively fixed since it isn't set by a stop but
rather by the pushrod. It's unclear how to correct a rolling tendency with
flaps deployed should this occur -- Ed Kolano saw this problem with ELSA
during his evaluation flight, see "Sport Aviation" for August 1995.
Regards, John A044 Newtown, CT
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