Aircraft engine: Walter HWK 109-501
|Temperature in combustion chamber||2,000 ̊C|
|Working time||30 s|
|Thrust||1,500 kG (14,7 kN, 3,307 lb)|
Liquid-fuel rocket booster shortening take-off distance and facilitating take-off with heavy load. In front of the nacelle a parachute was mounted, enabling it to land softly after having been jettisoned from the aircraft. It allowed multiple use of the same engine. The propellant consisted of three components: 220 kg of 80% hydrogen peroxide (T-Stoff), 12 kg of calcium or potassium permangate (Z-Stoff) and 20 kg of kerosene mixed with hydrazine hydrate (Br-Stoff + B-Stoff). The propellant components were forced to the combustion chamber by compressed air. The combustion chamber was cooled with hydrogen peroxide.
The engine was designed in a small experimental facility Hellmuth Walter Kommanditgesellschaft in Kiel by Hellmuth Walter, who since 1935 worked on practical applications of the hydrogen peroxide, initially as propellant for submarines and then for aircraft. The HWK 109-501 was the development of earlier HWK 109-500 take-off booster, tested as early as 1937, in which so called „cold system” was used – the exhaust gases producing thrust were product of a chemical reaction, not combustion. Circa 3,000 take-offs were made with the aid of the HWK 109-500 engines during World War II. Further development of the engine was aimed at increase of thrust and work duration. It resulted in the HWK 109-501 with "hot" principle of operation, more elaborate composition of propellant and more sophisticated design. It was the reason of low popularity of this engine. It was used in 1944 during trials of the Junkers Ju 287 experimental jet aircraft with forward-swept wings.