BG wrote on 4/12/2020 9:45 AM:


Three: I am not aware of any crosswind problems for engine/pylon gliders caused by
lack of rudder efficiency. The propeller air goes directly past the rudder from
the nearby propeller on the pylon, increasing the rudder's effectiveness at least
as much as the FES, where the propeller is much further from the rudder.
Regardless, it is not the rudder that is used to keep the glider going straight
down the runway in a crosswind, but the steerable tailwheel (every glider should
have one). On my ASH26E, I hold the tail wheel on the ground until about 25 knots
airspeed, then lift it off by moving from negative flaps to positive flaps (soft
fields may need a different technique).


I find a huge difference in cross capability in my DG 800 on pavement vs. dirt or grass. You need help from the wheel on the ground to prevent weather vanning. I find the fringe turbulent thrust from the engine is not so effective on the rudder, standing behind the glider you fill most of the prop thrust is up near the elevator anyway. The pylon thrust line lifts the tail and reduces traction on the rear wheel. I have lost track of how many aborted takeoffs I have had in strong cross winds, while gliders being towed were doing just fine off dirt and grass..

I don't have any personal experience with the DG 800, but your description shows
it's very different in some respects from my ASH26E. I had no idea it was so bad,
or I would not have made such a general statement.

What measures have you tried to improve the soft field, crosswind takeoff? Are
your takeoffs unassisted? If so, have you tried placing the downwind wing on the
ground to help counteract the weathervaning from the wind?

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1