What is the origin of the term “military power”?

Question

An engine producing 'dry' thrust is said to be at 'military power', a useful distinction from reheat / afterburner.

It's always seemed an odd phrase to me. There's nothing particularly military about it, and why would afterburner not be military? 'Military' has always been used as a word that always relates to soldiering in some form or another - it is a curious choice to define the operation of a jet engine.

It must, of course, be a twentieth-century phrase. Can any light be thrown on its origin?

Answer 1

The etiology of military power is from War Emergency Power (WEP) which in the WWII era was a higher than normal rating power (i.e. >100% rated power) setting on an aircraft engine. Such power settings were approved for short durations (typically 5 minutes or less) such as takeoff and battle maneuvers.

The term was quickly shortened to military power.

Sometimes military power is assumed to be simply full throttle, but that may not be accurate, particularly in blown engines, where turbochargers or superchargers may be set to permit higher than normal air delivery to the combustion chamber.

Finally, military power was used for more extended periods of times, when conditions dictated, but at a reduction in reliability and service life. Sometimes in war, service life is not a pilot's greatest concern.

Answer 2

"Military power" is less about the distinction between dry and wet thrust, but more about the distinction between civilian "maximum power" and "military maximum powerÄ which usually puts more strain on the engine than desired in a civilian context.