50+:1 15m sailplanes

The info appears to be from a handout at the Sailplane Homebuilders
Association's Western Meeting at Tehachapi, CA, in September 2003. I
can't find my copy of the handout, and the website only mentions the
DuckHawk (Peregrine falcon, but maybe that name was taken, or more
likely, to match with the SparrowHawk now being produced).

BTIZ wrote:
I don't see it on their web page..

BT

"Paul T" wrote in message
...

Here's the figures on the American DuckHawk (got to
be one of the most awful names for a sailplane) from
the promo sheet.

Windward Performance LLC takes its advanced technology
to the racing class.


Specifications
Empty Weight 300 LBS
Gross Weight 900 LBS
Wing Span 49.17 FT
Wing Area 74.93 FT^2
Aspect Ratio 32.2:1
Length 20.6 FT
Horizontal Span 6.8 FT
Vertical Height 4.5 FT

Structural Limits
+11.0 / -9.0 g's
Va, Vb = 165 KTS
Vne = 200 KTS

Performance
At 500 LBS, 6.7 Lbs/FT^2
Best Glide 50:1 at 50 KTS
Min Sink 94 FPM at 40 KTS
Stall Speed 35 KTS

At 900 LBS, 12.0 Lbs/FT^2
Best Glide 52:1 at 67 KTS
Min Sink 122 FPM at 57 KTS
Stall Speed 47 KTS
(data for 900 LBS, 12 PSF)

Airfoils
Inboard 12.7 % t/c
Outboard 10.2 % t/c


The DuckHawk has the broadest wing loading range available,
the highest maneuvering and redline speeds, and the
lowest inertias for snappy handling. The lower flying
mass within the 15m span constraint gives an induced
drag advantage of 49% at 500 LBS and 33% at 900 LBS
(span loading squared) compared to the competition


Time will tell - my money is on the Diana 2 which is
a development of the SZD-56-1 Diana. (Whose cockpit
is bigger than a Ventus a!). Incedently at Leszno they
were also talking about an 18m version and 22m Open
class version.








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Eric Greenwell
Washington State
USA