bagmaker wrote:

does the tow charge cover all the a/c costs, like insurance, maintenance,
replacement after time etc?

Everything. The tow plane just pays itself, everything included. The
calculation is done on the basis of the estimated total hours over the
year and recalculated and adjusted every spring.

We charge per minute, airborne to touchdown of the tow plane. With this
method, the glider pilot is absolutely free to decide where and how high
he wants to tow. (We have several release points, depending on the
weather, the time of day, where you want to fly and whether you want to
fight in your first climb or just release and go. And of course all our
gliders are radio equipped, so we can direct the tow pilot. (Such as in
"Try that big cloud at 10 o'clock."))

We expect the tow pilots to make the round trip as short as possible,
and they do their best. Of course there are some who do better than
others, and sometimes they manage to find thermals to accelerate the
climb, and sometimes they do not. We believe that it averages out over
the year and that charging per minute is the most transparent and
flexible method.