On Apr 22, 4:43*pm, Robert Danewid wrote:
Thanks

My problem is that some one has found a supplement named S1A-77 to the Flight Manual of a 180 hp PA 18 that says that max glider weigth is 600 kg. Can any one send me or direct me to that supplement.

It does not make sense...... We have been towing gliders 600 kg with PA 18 150/180 since the early 80ies.

Robert

OK, having nothing else to do this afternoon, I did some research.
The 600kg number suggested a European sourced supplement. US STC's
would likely be in SAE units.

It appears there is a MOGAS STC issued in Switzerland to Wenger &
Kaufmann for PA-18-180-M and PA-18-150 glider tugs. In pursuit of the
STC the glider tow performance (takeoff roll, climb rate) was measured
with a 600kg glider in tow. Since that is the heaviest glider tested,
that became the limit for the STC. This may or may not the source of
S1A-77 but it shows how it can happen. There are LOTS of different
STC's for PA-18 around the world.

This is a bit if a diversion but most recent European 2-seaters
specify 600kg (Actually, 600 daN) weak links for aero tow. If these
gliders are operated in strict compliance with their Approved Flight
Manuals as required by FAR 91.9, 600kg would be the max load on the
tug.

I have been assuming (possibly in error) that you are in the US.