Definition
The setting of the engine bleed air system — the valves and switches that route compressed air tapped from the engine's compressor section to systems such as air conditioning, pressurization, and anti-icing. The configuration determines how much engine power is being diverted to these systems versus available for thrust, which directly affects takeoff performance.
Plain English
How the airplane is set up to use air taken from the engines to run things like cabin air, pressurization, and ice protection. Different settings use more or less engine power, which changes how much thrust is left for takeoff.
Context Anchor
Seen in takeoff performance planning, takeoff checklists, and rejected takeoff discussions, especially in turbine airplanes.
Derivation
Bleed' here means to draw off or tap — like bleeding off pressure. The engine's compressor squeezes large amounts of air, and some of that high-pressure air is 'bled' off and routed elsewhere in the airplane.
Why Pilots Care
Incorrect settings reduce available thrust, lengthen the takeoff roll, and can prevent meeting required runway performance.
Grounding Statement
When bleed air is on, the engine is sharing some compressed air with other airplane systems instead of using all of it for takeoff power.
Intuition Check
Do not read bleed air configuration as a general cockpit setup. Here it specifically means the on/off setup of systems that take compressed air from the engine.
Example Sentence 1
Before takeoff, the crew confirmed the bleed air configuration matched the performance numbers used for their runway and weight calculations.
Example Sentence 2
With the bleed air configuration set for maximum thrust, the engines produced the calculated power needed for the short runway.