To put it simple, I would like to know how many minutes
it takes for a
Rotax
Falke with the 912S engine, to tow an ASK-21 (fully
loaded, or close to)
to
4.000 ft./1.200 meters, in calm air?

Is that 4,000 ft above amsl, or above site?

What ambient temperature etc?

My only experience of being towed by this type was
in (or should I say
on) a Primary, at a very steady 42 mph! I would be
surprised if it gave
acceptable performance for really high wing loadings
though.

Ray