Multijet airplane starter-generator controls

Most electric control systems and their respective components designed for a multijet airplane are in many respects much the same as those used on reciprocating engine-type airplanes. This is true also with respect to the starter and generator system as used on a recently developed 6-engine jet airplane. One main difference, however, is the starter and generator components themselves. On a standard reciprocating engine-type airplane these two components are separate entities having their own control systems. On this multijet airplane the starting and generating functions are performed by a single unit. This unit is called a “starter-generator” and is rated at 400 amperes, 30 volts direct current, capable of supplying a continuous output of 400 amperes at engine speeds from 4,000–8,000 rpm. The electric system designed to control the starter-generator and its supporting components was patterned, in the early designs, after comparable systems used on standard reciprocating-type airplanes. Modifications, and in some respects complete redesign, of parts of the control system were necessary in order to provide a system which would perform according to the more exacting requirements demanded of it.