Bob Whelan wrote:

That noted, choosing to continue to use older ships (e.g. Schweizers,
Grobs [don't laugh, my club is presently in the throes of precisely this
debate, and a 102 and 103 are 'the bad ships'], AS K-7/13's etc.), is
*NOT* a acornworthy decision, any more than an individual choosing to
keep and maintain an older vehicle (assuming it still meets its mission)
in place of periodically updating it 'just because,' is. Both
approaches have value, and pros, and cons.

Personally, until someone can, or, events (some other club's, ha ha)
demonstrate to me that a bet-the-club, economically risky
(gambling-based?) approach to growing (as distinct from merely
'churning') soaring has value, I find it difficult to out-of-hand
dismiss continuing to use proven hardware that with fundamentally low
carrying costs.

I'd just like to add one thought: IMO the utility of low performance
trainers depends quite a lot on launch method.

I learnt on ASK-21 / G.103 / Puchacz off a Supacat winch, which pretty
much guaranteed 1200 feet with these gliders under calm conditions and
could give up to 2000 ft as wind strength rose. 1200 ft gives about 7
minutes in no-lift conditions with any of these trainers and a good
chance of thermal flights if there is much lift about. I did all my spin
training, apart from the initial demo, off the winch. IOW we found
enough lift to easily get to 3000+ feet on those flights.

By contrast, I periodically make attempts to get type approval for our
T.21b but its hard going. At 20:1 you don't cross the airfield boundary
without a good thermal climb, so a typical flight is a bare 5 minutes.
The T.21b doesn't climb well on the cable. This is barely enough time to
get a feel for the glider before you're turning base.

From this I make the, possibly dangerous, generalization that if your
club normally aero tows your can get by with lower performance trainers
than, e.g. a flat land winching site can use.

As a corollary, there's an obvious trade-off between tow vs winch costs
and the cost of low performance vs high performance two seaters. If, as
I suspect, increasing fuel prices tilt the balance toward winching then
just maybe the older, low performance trainers will start to look less
attractive.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |