Designed by a group from the Akademische Fliergruppe Stuttgart, the Institute of Mechanics and Aircraft Design of Stuttgart University, and Wolf Hirth GmbH, the Fs-28 Avispa research aircraft was undergoing flight test in 1974.
The Fs-28 is constructed of resin-bonded honeycomb sandwich plastic and has a 115 hp Lycoming O-235E-2A installed in the rear. An inverted V tail is attached to twin booms. A special three-bladed propeller was developed with Hoffman to educe noise level.
The cockpit seats two side-by-side; the doors are two swing-up side panels. Fowler flaps are fitted.
Engine: 115 hp Lycoming O-235E-2A
Cruise 75%: 155 mph
Max speed: 167 mph
Landing speed: 50 mph
Range: 620 mi with 30 min res
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