Aériane Swift

The Aériane Swift^[1] is a lightweight (48kg) foot-launched tailless sailplane whose rigid wings have a span of 40 feet.

Although designed in California, Swift aircraft are now manufactured by Aériane, a European firm based in Gembloux, Belgium.^[2] Aériane first manufactured the Swift under licence, but the firm is now the sole manufacturer.

Design & development

The Swift was originally conceived as a rigid hang glider with sailplane-like performance. It was designed in a collaboration between Bright Star Gliders and Ilan Kroo, a professor at Stanford University, along with a group of Stanford graduate students. The Swift's configuration as a foot-launched sailplane with rigid wings is shared by a very small number of gliders.

The swept wing has control surfaces along the entire trailing edge: flaps occupy the inner 42%, and elevons take up 58% of the outer span. The Swift has no vertical stabilizer and so faces the need for directional stability in yaw. This is addressed by winglets and the models with an enclosed cockpit also have conventional fuselage stabilising surfaces that contribute to yaw stability. The winglets on the 1990 prototype were fixed surfaces, so the pilot effected turns using the elevons.^[3]

The original Swift is now out of production, having been replaced by a refined version called the Swift'Lite. This new model has winglets that, like those on the Rutan Long-EZ, are rudders when used singly, and air-brakes when used together.^[4] In addition, compared to its predecessor, the Swift'Lite is claimed to be: 20% lighter, with lighter and more responsive controls, a lower stall speed, an improved glide ratio of 27:1, better pilot visibility and comfort, and simplified assembly procedure.^[5]

Model range

A variety of different "fuselage pods" have been fitted beneath the wings to create a range of aircraft, as follows:

• the core product is the foot-launched glider (the Swift'Lite)
• a self-launching glider (the Swift-PAS) with 12 horsepower (8.9 kW) two-stroke engine, later with a 18hp Bailey four stroke engine
• a motor-glider (the P-Swift) with 25 horsepower (19 kW) 2-stroke engine
• an electric-powered variant (the Icao Electric Swift), with 20 minutes of powered flight per charge.^[6]
• a two-seat glider used for training (the Tandem Swift)

The various fuselage frames are interchangeable and any can be added to the same basic wing. Swift gliders with engines have Arplast EcoProp folding propellers, which feather for soaring when then engine is turned off. Powered Swift gliders are not foot-launched, having instead two main wheels in tandem layout, and small wing-tip castors.

Specifications (Swift'Lite)

Data from ^[7]

General characteristics

• Crew: 1
• Wingspan: 42 ft 0 in (12.80 m)
• Wing area: 136 sq ft (12.6 m²)
• Aspect ratio: 13:1
• Empty weight: 106 lb (48 kg)

Performance

• Rate of sink: 200 ft/min (1.0 m/s) in a 100 ft (30 m) radius turn
  
• Minimum sink rate: 118 ft/min (0.6 m/s)
• Lift-to-drag: 20:1 (maximum) 15:1 at 60 kn (111 km/h)

Aircraft of comparable role, configuration and era

Mitchell U-2 Superwing

References

External links

• Dr. Ilan Kroo and Eric Beckman with Brian Robbins, Dr. Steve Morris, and Brian Porter "Development of the SWIFT -- A Tailless Foot-Launched Sailplane", Aeronautics Department, Stanford University, January 1991.
• , A detailed report of the flying characteristics of the hybrid follow-up design to the original SWIFT.
• Ruhm sailplanes (UL RuhmAir Leichtflugzeuge / Mannfred Ruhm)