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Old November 13th 04, 12:49 PM
Charles Yeates
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May be way off but I recall Tom knauff talking about Schemp Hirth using
about 400 hours per Discus / Ventus ?

What I think we need is a new way of building gliders.

You cannot reduce certification costs nor development costs but you can
reduce material and labour costs.

What I had in mind when I made my earlier post re mass production was not a
production line that produces a glider a day or anything that optimistic.
However there has got be another smallish step up from what we currently do
that will result in a dramatic reduction in the costs and hence price. The
question is what is the critical mass number that will give us this
production advantage ... I dunno the answer - I doubt anyone does. It is
well known (as one other post states) that Cessna produced airplanes in
approx 300 hours. That is a long way from where we are currently at for
composite gliders ... and that is for a much more complex airplane than any
glider. The question is simply what level of tooling and investment is
required to get to this next level and what gains will that give us in
production cost and hence volume.

Assuming a composite glider, what I have in mind is tape laying machines,
filament winding, RTM methods etc. All other areas of the composites
industry are moving this way - I am sure sailplanes will eventually. There
are also other innovative ways to build sailplanes if we are really willing
to think outside the square. Also CNC machines for all metal parts etc. Also
the design is important we need more efficient design processes and tools
and more effort needs to be invested to reduce parts count. Perhaps there is
a better way to build a composite airframe than the standard foam sandwich
approach. We will not know unless we challenge ourselves to do it.

The Sparrow Hawk while a commendable design effort will never be a
commercial success (as another poster pointed out). It is too labour
intensive to build, the cost of materials (Toray carbon prepregs I seem to
recall) are too expensive (carbon prepreg tape is 1/4 the price woven cloth
per metre sq for instance) and it is not certificated which significantly
reduces the size of the potential market (and the design is barely legal
under Part 103).

Similarly the discussion on kits gliders is a bad example when compared to
say an LS-4. These are only cheap because the builder has to invest a lot of
labour and because they are not certificated.

There is ample evidence in the hang glider world and indeed in other leisure
sport products that the volume would increase dramatically if the price
could be reduced. Imagine if you could sell a certified APIS for 150% of a
current list price of a competition standard hang glider what that would do
to the volume of glider sales. Waiting in a queue for a club glider would be
a thing of the past - you would simply buy your own - the increase in volume
would come from within the existing gliding fraterity, not to mention the
more people the sport would attract and retain through greater
affordability. I don't know exactly how many hang gliders are sold annually
but recent articles I have read indicate that it is thousands a year. Anyone
got any hard data ????? How many gliders do Schempp Hirth, DG, et al sell a
year ... anyone got some data ?????

Finally you don't need to point out that the above is somewhat idealistic. I
am very aware of this but unless we look to the future, challenge ourselves
to do better and make significant progress in the direction of costs and
affordability we will not have a viable sport. Someone has to start to do
the dreaming if we are going to have any hope of solving the problem. Anyone
share that vision ?