Thread: Glider Shapes
View Single Post
  #22  
Old January 5th 08, 05:17 PM posted to rec.aviation.soaring
Bill Daniels
external usenet poster
 
Posts: 687
Default Glider Shapes


"nimbusgb" wrote in message
...
The basic list raised by Gary is good. But there's nothing wrong with
parellelogram sticks.

If its less than 1:40 I'm not interested. It should be 'expandable' so
an optional upgrade to 18m wings perhaps?

The World class was based on price and it flopped heavily so sorry
price is way down the list.

I dont see why a 1:40 ship cant be built for low cost. Surely its the
airfoil and materials technology that have come on. An 1:40 libelle
must be possible with a modern aifoil or a 1:45 LS4


Exactly. There is no reason that a 'medium performance' glider should cost
much less than a 40 - 45:1 glider. They'll weight about the same and have
about the same parts count. The difference is almost entirely in the shape
and finish. If the manufacturer skimps on those, it won't sell at any price
so he might as well go for performance.

The main cost factor is production rate. Start on the demand side of the
economic equation. Re-jigger handicaps and competition classes to favor the
design. 'Seed' 2 - 3 gliders a year at large discounts into clubs that
foster X/C and competition as judged by their performance in the OLC and
their support for younger pilots in the Junior Class. The opportunity to
win an option to buy a new high performance glider glider at half price
would really drive the popularity of the OLC - AND the new glider.

On the supply side, once the manufacturer sees the demand, it's more likely
that investments will be made in cost saving production methods and tooling.
When the production rate ramps up, the unit cost will fall. For this to
work, the price has to fall far enough that used gliders don't 'suck the
air' out of the market - that's the incentive for the maker to keep the
price low.

It seems IMHO that picking a popular glider design that is now out of
production and tuning it up for mass production is a low risk way to go. An
LS-4 fits the bill nicely although there are probably others.

Even though some clubs will fear retractable gear I'd say keep it. As a
compromise, add threadded hard points on the belly allowing for a
sacrificial lightweight UHMWPE plastic skid to protect the belly in the
event of a gear-up. The hard points themselves would add little drag,
weight or cost.

Bill Daniels