Dan,

I'm sure you'll get a more informed answer than mine, as I'm still fairly
new to soaring.

The Mecaplex sliding window is held outward, against the canopy opening, by
two leaf springs that are riveted to the sliding portion of the window. It
could be that these springs are worn or have been bent so they don't provide
the original tension.

Trying to remove these springs may result in a cracked window if not very
careful. It may be possible to bend the springs a little to provide more
outward pressure (don't over do this or you'll weaken and ruin the spring).
You'll have to remove one rail to get the window out. To prevent cracking,
be sure not to over-tighten the mounting screws when re-installing the rail.

With the sliding window closed, closely inspect the "seal" for gaps.

To cure a sticking or hard opening sliding window (not the problem you asked
about, I know), spray a bit of silicone spray on a Q-tip and use this to
wipe and clean the slide rails.

Shameless ad: To quieten the flip out window vent, get a Quiet Vent kit (g).

all the best,

--
bumper ZZ (reverse all after @)
"Dare to be different . . . circle in sink."
QV kit and MKII Yaw String
wrote in message
ps.com...
The Mecaplex sliding window on my ASW 24 emits a loud whistle while in
the closed position, at all airspeeds.
The noise can be made to go away if I press firmly outward at the
trailing edge of the sliding window.

After a while it is so bothersome as to give me a headache. I have
tried stuffing a piece of paper towel in between canopy and window and
this will quiet the noise for the rest of the flight.

Note this canopy is a replacement, not original equipment.

Any ideas for a permanent fix would be appreciated.

Dan Fitzgerald