SOME POSSIBILITIES for shortening the field length requirements of present-day jet aircraft are:
Install leading-edge, high-lift devices which are retrofitable to present-day aircraft.
Retrofit — or purchase new — aircraft powered by turbofan engines. These have an inherently higher take-off thrust to cruise thrust ratio than the jets, which vastly improves the take-off acceleration.
Use boundary-layer control actuated by turbine discharge gas for immediate consideration in new aircraft engines.
Use direct-lift jet engines. These will improve the block speed characteristics of the aircraft and also give vertical take-off and landing capabilities.
This paper discusses the advantages of each of these possibilities. The author also describes the problem of airport location within a city, and its effect of total travel time.*