Hi Terry, The best report I can relay from personal experience was when
Keith Wilson and I flew the two demonstrator airplanes to Copperstate AZ,
then Cable CA, and then Montrose CO. We did takeoffs at density altitudes
up to 10,000 ft, at or even "slightly over" ;-) gross weight. One plane
turbo, one not. The 912S one has a whirlwind prop. We experimented with
different flap settings on the trike/912S and never found it to be wanting
for takeoff performance. I personally have had the trike up to 14,5000 feet
in the test program for that plane, and it was still climbing at 400 or so
feet per minute. The plane is on its way home as we speak and when it
arrives I will take it up to 8 or 10 thousand and try some full flap climbs.
I probably will not be able to find an 8,000-foot density altitude runway
otherwise in Florida! I'll post the results here then.
Regards,
Jim Thursby
-----Original Message-----
From: owner-europa@post.aviators.net
Subject: Stall strips
N135TD is a mono-wheel XS with 912S and a Whirlwind
constand speed prop.
Stall testing of N135TD at gross weight showed a
very benign gear/flaps up stall at about 50 knots. On the
other hand, the gear/flaps down stall is rather abrupt at
about 44 knots, with one wing falling off rather quickly
and the nose dropping to near vertical before recovery
can be made. We thought that it would be best to fit
stall strips, as recommended in the Europa pilot's manual,
as a stall like this on final approach could ruin your day.
Last Sunday we flew to Bishop, CA, which is at 4120 feet.
On take off, with two aboard and full fuel, I was unable to
get the airspeed above 52 knots with the gear/flaps down,
and finally had to slowly raise the gear/flaps to gain speed
(density altitude was about 7500 ft, weight was about
50 pounds under gross). Even after the gear/flaps were
up, climb was a rather anemic 250 fpm.
Given that we were already close to stall under these conditions,
both with the gear/flaps up and down, is it advisable to raise the
stall speeds even higher with stall strips ?
What kind of increases in stall speeds have other builders seen
whan they added the stall strips ?
Please note, Bishop is not a particularly high or hot airport in this
region. I can't help but wonder what kind of performance to expect
at higher places (Lake Tahoe, for example) on a really hot day,
where density altitudes can exceed 10,000 feet.
Terry Seaver
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