Terry and Dave,
Congratulations.
In my flight testing of the glider wing you have about the right numbers
on sink. The sink rate is affected by CG location, aircraft weight,
prop, etc. It really varies plane to plane.
The two tri gear I've helped finished can't get below 60 KIAS without
starting a high sink rate, but they were nose heavy and fat aircraft
(58.5 to 59 inch empty CG and 1050 lbs).
The airbrakes do cause a decided nose down pitch moment and when
deployed above about 85 KIAS they tend to vibrate.
Honestly, the Europa Motorglider is an airplane with soaring capability
rather than a glider.
In checking out others, I emphasize use of the airbrakes early, and when
approaching the flare lock them closed to prevent a possible nose down
pitch close to the ground and insufficient altitude to correct. I have
no experience with the mono motorglider, but the tri gear bleeds off
airspeed even with an Airmaster prop at a 1800 rpm idle. Crossing the
threshold above 70 KIAS is good for a long float though.
The ailerons are a bit heavy and the slightest roll, easily corrected at
low speed, requires more pressure to counter than I care to hold at
higher speed. I will never have a set of glider wings built in this
shop without aileron trim. I have adjusted the airbrakes to try to help
a heavy wing but aileron trim is best. Assuming the ball is centered of
course.
Without a trim tab, I used the glider technique of adding a shim of
filler under the elevator which re-contoured the lower surface. I added
a 1/16 inch high by 1 inch wedge of filler to the lower surface trailing
edge of the aileron needing to be raised, then flew, sanded the wedge of
filler down a little and flew again and repeated until it balanced well.
I then painted it and you can't even tell I contoured the surface, and
it flew really square...
I hope others with more experience can pipe up and give us all a little
more insight.
Again,
Congrats
Bud Yerly
Custom Flight Creations
----- Original Message -----
From: Terry Seaver (terrys)<mailto:terrys@cisco.com>
To: europa-list@matronics.com<mailto:europa-list@matronics.com>
Sent: Friday, February 29, 2008 1:09 PM
Subject: Europa-List: Motor glider first flight
<terrys@cisco.com<mailto:terrys@cisco.com>>
Dave DeFord and I have been flying our short winged mono-wheel Europa
for over 6 years now, and have been working on interchangeable long
wings for the past four years or so. We finally finished them and had
our first flight yesterday morning.
There was no drama, everything went well. We got in a total of four
flights, two each. A few comments are as follows;
1) There is a slight tendency to roll right, most noticeable a 100+
kts.
We are not sure yet what is causing this.
2) Very preliminary tests of the minimum sink rate were 400 fpm (at 50
kts indicated), later test indicated 350 fpm (at 52 kts indicated)
after
taping up the aileron and airbrake gaps. We had hoped for 250-280
fpm,
so we need to look for ways to improve this. Fairings for the
fixed-down outriggers are probably a good place to start.
3) The airbrakes are not as effective as the spoilers on the Katana
Extreme we got our glider ratings in last September. The air brakes
also cause a pitch/speed change, which causes some porpoising on
landing
if the brakes are used to modulate your approach/flare. The plane
also
tends to float a while in ground effect, even with full airbrakes on.
4) The mono-wheel twitchiness on the ground is greatly reduced by the
bigger, heavier wings.
5) The long wings add 103 pounds to empty weight, compared to the
short
wings.
6) Stall speed is about 45 kts indicated, with and without airbrakes
applied. As stall speed approaches, the plane just gets loose and the
nose bobs up and down. No tendency to break, it just bobs up and
down,
complaining about it. We haven't tried accelerated stalls yet.
Please note that these test are very preliminary.
Regards,
Terry Seaver
A135 / N135TD
Pleasanton, CA
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