This Procedure covers aircraft alternating-current generators. (With or without integral rotating exciters.) PURPOSE It is the purpose of this Procedure to define uniform acceptable test methods for determining the performance and other characteristics of aircraft alternating-current generators. Rotating electric equipment for aircraft is subjected to requirements and operating conditions not normally encountered by commercial generators. For example@ conditions of temperature@ altitude@ humidity@ and vibration vary over much wider ranges. Aircraft requirements dictate minimum weight@ and yet utmost reliability is essential. Weight reduction is generally achieved by sacrifice of life expectancy commensurate with aircraft practices. The necessity for accurate design requires that direct measurements to insure reliability and adequate life be an important part of this Test Procedure. It is recognized that there may be acceptable methods of making tests other than those described. Such other methods may be considered as alternative procedures accepted by agreement between interested parties. The tests outlined herein are not necessarily complete for any specific generator; and likewise the requirements in each case will determine the number of tests to be made.