The Germans are reported to have placed such take-off units in tactical use.
A possible explanation lies in the high altitude propeller used by the Luftwaffe.
This "prop," designed for flight at high altitudes, hampers take-offs.
German rocket experiments had been carried on for several years when the ;\AF launched its own intensive experiments in 1940.
The Germans first usctl rocket power for propelling gliders.
.As opposed to the jet propulsion engine, which takes its oxygen from the air, a rocket carries its own supply--making rockets theoretically capable of flying above the oxygen level.
Rockets carry both fuel and oxygen. Earl) experimenters used gasoline and pure liquid oxygen.
The burning fuel espands and is thus forced through a nozzle at the rear, giving the plane a forwarcl push---the same effect achieved in another way by jet propulsion.
3lateriel Command experts faced two major problems-suitable fuels anal oxidizers, and a nozzle which would stand the terrific heat of the ignited gas. This latter problem has been solved.
Better combinations of fules and osidizers still are being sought.
Two types of take-off units were developed, the fixed and the droppablc. Attack planes were equipped with the fixed type, with the nozzle emitting the gaseous flames from the rear of the engine nacelle.
Other, heavier planes, were equipped with droppable rockets attached to the underside of the wings. This type could be dropped by parachute and salvaged for use again.
The rockets are designed to operate until the plane is air-borne and the landing gear has been retracted.
AAlthough the tactical utility of the take-off units has been proved negligible, rocket experiments continue, with emphasis on sustained rocket flight, long ;I dream of pseudo-scientific fiction writers.
;it the current-stage, such rockcat engines are relatively ineffective.
- H. 0.