Nachricht geschrieben von "Joe Polenek"
>If there's anybody out there who has flown "conventional" gear and
mono-wheel gear under various conditions, that could make an objective
comparison, I would really appreciate some comment on this.
<
Hi Joe,
I have a few houndred hours of practice on the Scheibe SF 25 powered
glider, a tail-dragger that is available as monowheel and tri-gear.
As I've learned to fly on the monowheel, I can tell you that flying a
monowheel is something that can be learned - even for a beginner. The only
thing you have to do is to level the wings as soon as possible. Without
crosswind, this is no problem, with heavy crosswind it may be not so easy -
especially with the SF25 who's plastic sticks that hold the little wheels
under the wings bend under the load - you may have to be careful not to
scratch the aileron over the runway. I flew it under nearly all conditions
(storm, rain, snow, sometimes even good weather) from all kinds of
airfields (even mountain strips) and my experience is:
Advantages:
- better performance in flight
- better feeling for the plane during take-off (aerodynamic control already
before taking off, interesting especially with wet wings!)
- better damping on really bad runways (only one wheel detects the holes in
the grass)
- lower rolling resitance in deep snow / high grass / soaky grounds
Drawback:
- gigantic turn diameters in ground operations
- need for better skills (pilots who aren't able to level their wings
should stay on Cessnas)
Some flight instructors tell you that you shall lift the tailwheel early
and run on the main wheel - I won't do that. You 'll give up prop clearance
and without angle of attack you do not lift the plane as early as possible
which increases take-off distances on grass or mud.
Under crosswind conditions you may want to "pull" a little bit to force the
steering tailwheel to the ground - after take off the plane yaws into the
wind with a considerably higher airspeed (relative wind vector is now
directly on the nose).
It may even be better than with "normal" tri-gears: If the rudder has no
effect and you have no steering tailwheel, the only thing you can do is
braking against the wind - not very desireable during take-off runs!
As I said - I never had a real problem with this monowheel powered glider
caused by it's gear configuration, nor during take off, neither during
taxiing. Once in the Central Massif of France, We had 40 knots under an
angle of 60-70 deg. to the runway with strong turbulences over the field
(this is stormy weather!). I decided to land directly into the wind - a
helicopter-like landing with 15 meters ground run ... Take off after
refueling has been done on the runway after the wind calmed down a bit -
but still with 20-25 knots and 35 knots in peaks. In a STOL plane (like the
SF25 or the Europa) your ground speed is so slow that you only have to
decide if you want to pull out the throttle and roll a few more meters or
if you want to fly away if a wind gust is trying to blow you away ;-)
Tri-gears are made for pilots who never pack their tent and sleeping bag
for a trip into the mountains, who wear frottee underwear and always take
warm showers. I recommend monowheels.
HTH,
Jens
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