Definition
The amount of engine power needed to maintain a given airspeed in level flight at a specific weight, altitude, and configuration. It is the power that exactly overcomes the total drag acting on the airplane at that airspeed, so the airplane neither accelerates nor decelerates and neither climbs nor descends.
Plain English
How much power the engine has to produce just to hold a steady speed in level flight. Less power than this and the airplane slows down or sinks; more than this and it speeds up or climbs.
Context Anchor
Seen when discussing how pitch and power control the airplane’s energy state, especially when changing speed, climbing, descending, or maintaining level flight.
Derivation
Power means the rate of doing work. Required comes from a word meaning “asked for” or “needed.” Together, the term points to the power the airplane needs for the flight condition it is in.
Why Pilots Care
It shows the airspeed at which minimum power is needed and where excess power becomes unavailable, directly affecting climb performance and stall avoidance.
Grounding Statement
At a higher-drag setup, such as with flaps extended, the airplane usually has a higher power required to hold the same flight path.
Intuition Check
Do not read “power required” as “the maximum power the engine can make.” It means the amount of power needed for the airplane’s present speed, drag, and flight path.
Example Sentence 1
As the airplane slowed below best glide speed, the power required actually increased because induced drag was rising sharply.
Example Sentence 2
Above the minimum-power speed, power required increases rapidly because parasite drag grows with the square of airspeed.