Electrical Power for Supersonic Airliners: A discussion of the merits of wild frequency alternators and fixed frequency alternators

CURRENTLY it is usual to demand that the entire electrical power for proposed super‐sonic airliners should be generated at a constant (400c/s) frequency. In order to do this a device called a constant speed drive (C.S.D.) is used to couple the shaft take‐off from the main propulsion engine to the electrical generator. These constant speed drives are extremely expensive items requiring specialised maintenance. On current subsonic airliners they absorb approximately 80 per cent of the time and expense required for the maintenance of the entire generating and distribution system on the aircraft. If these constant speed drives could be dispensed with a great step forward in simplification would result.