EFF (ENTWICKLUNGSGEMEINSCHAFT FOR FLUGZEUGBAU DER AKADEMISCHEN FLUGGRUPPE)
The Prometheus 1 was an experimental powered sailplane, based on the airframe of the FFA Diamant 18. Design and construction began in late 1970, and the aircraft flew for the first time on 21 June 1971, powered by a 176 lb (80 kg) Microturbo Eclair II turbojet engine. This had been later replaced by a more powerful TRS 25 engine.
Wings, Fuselage, tail units and landing gear are coming from an original Diamant 18.
One 264 lb (120 kg) st Microturbo TRS 25 turbojet, mounted on a pylon above the wing center-section.
Total fuel capacity
Fuel in two 8-75 Imp gallon (40 litre) wing tanks and one 0.4 Imp gallon (1.8 litre) fuselage tank.
Total : 17.9 Imp gallons (81.8 litres).
0.11 Imp gallons (0.5 litres).
Dimensions and areas
|Wing span||18,0 m||59 ft 0.5 in|
|Wing aspect ratio||22,5|
|Length overall||7,56 m||24 ft 9.5 in|
|Height over tail||4 ft 5 in||1,35 m|
|Tailplane span||9 ft 6,25 in||2,90 m|
|Weight empty||290 kg||639 lb|
|Max T-0 weight||500 kg||1,102 lb|
|Max level and living speed||270 km/h||146 knots||168 mph|
|Max cruising speed at S/L||210 km/h||113 knots||130 mph|
|con cruising speed at S/L||170 km/h||92 knots||106 mph|
|Stalling speed, flaps up||80 km/h||43.5 knots||50 mph|
|Stalling speed, flaps down||68 km/h||37 knots||42.5 mph|
|Max rate of climb at S/L (/min)||180 m||591 ft|
|Service ceiling||11,000 m||36,100 ft|
|T-0 run||300 m||984 ft|
|T-0 to 50 ft (15 m)||450 m||1,476 ft|
|Landing from 50 ft (15 m)||150 m||492 ft|
|Landing run||50 m||164 ft|
|Range with max fuel||> 135 nm||> 250 km||> 155 miles|