On Mon, 15 Mar 2021 08:16:18 -0700, waremark wrote:

On Sunday, 14 March 2021 at 01:04:39 UTC, Martin Gregorie wrote:
On Sat, 13 Mar 2021 16:19:14 -0800, waremark wrote:

I have carefully considered the pro's and con's of buying a self-
launching K21 and have concluded that it does not make any sense to
operate one or two of those alongside a fleet of tugs and pure
gliders.

Out of pure curiosity, why would you consider using self-launching
K-21s when you have at least one winch?


Our field is much smaller than yours. A typical winch launch height is
1,000 foot, and there is a long ground retrieve from the normal landing
area to the launch area. So the winch is productive in terms of numbers
of launches from the site if their are several gliders using it and
enough people on the ground for efficient operation, but it is not
productive for an individual student. We do not use it for trial lessons
or introductory flights where we want people to have longer in the air.

For an individual student, a self-launcher which can taxi back to the
launch area after landing would enable the sort of booked session
typical at a power club - say 2 hours at the airfield for one hour of
flying time. For delivery of introductory flights, an individual
instructor could quite easily do two 20 minute flights per hour.

Thanks for that info - I must admit that I tend to think of 1400 ft as a
normal winch launch height because that's what I learnt on, and of course
the width and length of the space behind our usual launch points on 04/22
does make for faster turn-rounds. Its noticeable just how much the launch
rate drops if the wind dictates we operate on 16/34 or 09/27, which are
both much narrower runways.


--
Martin | martin at
Gregorie | gregorie dot org