The Kestrel is a high-aspect ratio Rogallo hybrid with a unique ram-air, flight-inflated, Airfoil-shaped ‘bubble’ over the centre section leading edge. The forward third of the wing is covered by a second sail which inflates in flight. This forms an Airfoil which is claimed to improve efficiency and give mellow flight characteristics. Battens, located from the bubble leading edge back to the trailing edge, improve sail efficiency and stability.
Like other high-aspect ratio hang gliders with short keels, the quarter chord sweepback angle is greater than a standard’s, which contributes to the Kestrel’s pitch response and stability. The sail-roach patern and battens eliminate the need for finite tip extensions. A double deflexer system is used on each leading edge to limit airframe deformation.
It is controlled solely by weight shifting. Take down / setup times should be less than 10 minutes and the Kestrel may be transported like a standard. It can be flown either seated or prone.
The Kestrel B was the first glider to employ a double surface sail. The forward third of the wing is covered by a second sail which inflates dynamically in flight. The second surface includes a semi-rigid, non-deflatable, airfoil-shaped center section, giving one of the largest flying speed ranges. Because of the semi-rigid centre section and trailing edge batten features, the Kestrel B’s sail cannot be put into a full-luff streamering mode, further aiding dive recoverability. The Kestrel B was recommended for class III or IV pilots due to the relatively high L/D.
A rounded nose plate helps prevent sudden stops during landing. The rigging can be adjusted easily for either prone or seated flight, and there is an adjustable centre of gravity. It is capable of being packed to about half the leading edge length.
The airframe is made from aircraft quality 6063-T832 in both model sizes. Dowelling is not used, for lighter weight. Strength instead comes from stainless steel bushings and inside sleeving. Deflexers help keep the leading edges straight.
The rigging is marine stainless steel 3/32in 7×7 throughout with protective coating on the bottom wires. Quick links and pins are used so the rigging and control frame can be easily removed.
All hardware is of stainless steel or aircraft quality aluminium. Nuts, washers, bolts, and turnbuckles are aircraft grade.
The sail is made from 3.8oz stabilised dacron with double zig-zag stitching. Threre are three battens on each side from the trailing edge to the double surfaced section. The centre section includes a removeable rib and Velcro/snap closure.
There were five standard colour patterns from one to five colours.
Either a swing seat or supine harness were available.
Kestrel
Wing span: 30 ft 6 in
Wing area: 185 sq.ft
Aspect ratio: 5.0
Keel length: 11 ft
Leading edge length: 19 ft 6 in
Nose angle: 102 degrees
Empty weight: 40 lb
Max flying weight: 225 lb
Useful load: 185 lb
Best L/D: 7 – 1
Min sink: 250 fpm
Stall: 15 mph
Cruise: 25 mph
Kestrel B 19×11
Leading edge: 19.5 ft
Keel length: 11 ft
Wing span: 30 ft
Wing area: 190 sq,ft
Aspect ratio: 5
Nose angle: 102˚
Weight: 40 lb
Pilot weight: 135-185 lb
Stall speed: 15 mph
Best glide ratio (L/D): 7-1
Min sink: 250 fpm
Kestrel B 20×12
Leading edge: 20.5 ft
Keel length: 12 ft
Wing span: 31.5 ft
Wing area: 220 sq,ft
Aspect ratio: 5
Nose angle: 102˚
Weight: 43 lb
Pilot weight: 170-240 lb
Stall speed: 15 mph
Best glide ratio (L/D): 7-1
Min sink: 250 fpm
