At 07:15 PM 5/04/05 +0930, you wrote:
>Mike, before I weigh into this issue, when you said:
>
>"The PW5 was a really dumb idea that saw the light of day because not enough
> IGC delegates were smart enough to vote against it."
>
>Did you mean the "World Class Glider" concept was a dumb idea or the PW5 was
>a dumb selection?
>
>Regards
>
>Chris McDonnell
Both.
1. The trailer, instruments, launches, time off, travel, etc cost about the
same regardless of the airframe type. There may be small savings in weight
towed and a smaller car might be possible but against a 15m/Standard glider
we are talking less than 100Kg empty sailplane weight. So any cost savings
are largely illusory.
2.The premise was that there was a large pent up demand for contest gliding
which could be realised by providing a "cheaper" glider that would not
rapidly become obsolete. The estimate was that they would sell 3000 in the
first 5 years. They sold about 200 or a few more. Obviously something was
wrong.
3.The PW5 is *ugly*. It doesn't even look much like a modern glider. If
they had put the same wings on say an SZD55 fuselage they might have been
on to something. The PW6 two seater looks much nicer.
4. The PW5 wasn't particularly cheap. It was far more expensive than an
older glider with 30% better performance.
5.Choosing to go with performance that was typical of production gliders 30
years before the selection is inexplicable. In that thirty years the
fiberglass revolution occurred. More performance = fewer
outlandings(outlandings are not fun) and more days that can be contest
days.(wind etc). Performance is also *fun* in itself. The selection
guidelines were faulty.
6.The "club" class is the "world class". It allows use of gliders that are
obsolete for current FAI class contests.(Why "sports class" got renamed has
to do with political correctness and more flogging of dead horses I
suspect). There may be a need for an A and B club class as time goes on.
Handicapping is easier and fairer if the performance disparity is too great.
7. The IGC only promised to freeze the World class rules for 10 years I
think. Currently and for some time before, the life of a top FAI contest
glider has been at least that long.
8. Choosing a winner in a contest structured like the World Class selection
is guaranteed to result in production of a prototype. Most machines benefit
from engineering improvements. If you are going to do this select a short
list and tell them to go away for 12 months and improve their products.
Then make a selection.
9. Given what showed up the committee could have said none of the machines
are suitable. It has been done before in design contests sponsored by the
BGA and GFA. There may be other instances.
10. This kind of contest is like governments "picking winners". That works
out well usually doesn't it? Private citizens vote with their wallets
and/or feet.
11. Much(but not all - the advent of carbon fiber and custom designed wing
sections in that 1970's was another small revolution - the last one so far)
of the "obsolescence" of gliders during the 70's 80's and 90's was simply
due to ever increasing wing loadings. We now have 600Kg 18m missiles.
The simple way to guard against this would have been to limit the max
flying weight in contests of limited span classes. It happened in open
class for a while but the IGC seems intent on stuffing that up too by
upping the max weight limit. Wing loading won't do it as the next
generation simply gets more chord. Limit the span and the weight and you
are then free to do the best aerodynamic design. You will find there has
been very little improvement in that for the last 25 years.
I cannot think why in contests the glider weight should not be limited to
the heaviest glider/pilot combination flying in that contest. Others
ballast to that weight.
That's just a random selection of thoughts.
Mike
Borgelt Instruments - manufacturers of quality soaring instruments
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