Definition
A ground or in-flight test performed on a turbine engine to verify that it is producing the power the manufacturer says it should produce at given temperature, pressure, and altitude conditions. The pilot or technician records engine readings (such as torque, turbine temperature, and gas generator speed) and compares them against published charts. If the engine meets or exceeds the chart values, it is producing rated power; if it falls short, the engine is degraded and may need maintenance.
Plain English
A check that confirms a turbine engine is still producing the power it is supposed to. You run the engine, read the gauges, and compare them against the numbers in the manufacturer's chart for today's conditions.
Context Anchor
Pilots may encounter this during a run-up, after engine maintenance, during a scheduled check, or before a flight where full engine performance is especially important.
Derivation
Power assurance simply means assuring -- making sure of -- the power. The phrase is plain English used as a formal procedure name.
Why Pilots Care
Confirms the engine will meet takeoff and climb performance requirements, especially in hot or high conditions where power margins are critical.
Intuition Check
Do not read this as a casual look at the throttle or a general engine run-up. A power assurance check is a specific comparison between engine readings and approved performance numbers.
Example Sentence 1
Before the first flight of the day, the pilot completed a power assurance check and recorded the torque and turbine temperature in the aircraft logbook.
Example Sentence 2
After the compressor wash, the mechanic ran a power assurance check to verify the engine had regained full performance.