The Sperwill ST is a British

paramotor Paramotor is the generic name for the harness and propulsive portion of a powered paraglider ("PPG"). There are two basic types of paramotors: foot launch and wheel launch. Foot launch models consist of a frame with harness, fuel tank, engine, ...

that was designed by Riann Oliver and produced by Sperwill Ltd of

Bristol Bristol () is a city, ceremonial county and unitary authority in England. Situated on the River Avon, it is bordered by the ceremonial counties of Gloucestershire to the north and Somerset to the south. Bristol is the most populous city in ...

for

powered paragliding Powered paragliding, also known as paramotoring or PPG, is a form of ultralight aviation where the pilot wears a back-pack motor (a paramotor) which provides enough thrust to take off using a paraglider. It can be launched in still air, and on ...

. Now out of production, when it was available the aircraft was supplied complete and ready-to-fly.Bertrand, Noel; Rene Coulon; et al: ''World Directory of Leisure Aviation 2003-04'', page 75. Pagefast Ltd, Lancaster UK, 2003. ISSN 1368-485X

Design and development

The aircraft was designed to comply with the US

FAR 103 Ultralight Vehicles Ultralight aircraft in the United States are much smaller and lighter than ultralight aircraft as defined by all other countries. In the United States, ultralights are described as "ultralight vehicles" and not as aircraft. They are not req ...

rules as well as European regulations. It features a

paraglider Paragliding is the recreational and competitive adventure sport of flying paragliders: lightweight, free-flying, foot-launched glider aircraft with no rigid primary structure. The pilot sits in a harness or lies supine in a cocoon-like ' ...

-style wing, single-place accommodation and a single

Hirth F-33 The Hirth F-33 is a single cylinder, two stroke, carburetted aircraft engine designed for use on ultralight aircraft, including powered paragliders and ultralight trikes. the engine is noted for its extremely light base weight of . It is ma ...

engine in pusher configuration with a 2.3:1 ratio

reduction drive A reduction drive is a mechanical device to shift rotational speed. A planetary reduction drive is a small scale version using ball bearings in an epicyclic arrangement instead of toothed gears. Reduction drives are used in engines of all kinds ...

and a three-bladed, fixed-pitch wooden propeller. The fuel tank capacity is . The aircraft is built from a combination of bolted

aluminium Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. I ...

and 4130 steel tubing and dismantles for ground transport. As is the case with all paramotors, take-off and landing is accomplished by foot. Inflight steering is accomplished via handles that actuate the canopy brakes, creating roll and yaw.

Specifications (ST)

References

{{Sperwill aircraft ST 2000s British ultralight aircraft Single-engined pusher aircraft Paramotors