RAM recovery describes which engine performance change?

• A. A decrease in engine thrust during cruise.
• B. The increase in thrust as a result of ram air pressures and density on the front of the engine caused by air velocity.
• C. A method for reducing engine noise.
• D. The loss of thrust during high-angle-of-attack.

Answer: (B)

The key idea is how moving air at speed adds pressure at the engine intake, giving a small boost to performance. When the aircraft travels faster, the air striking the engine face is decelerated, and that kinetic energy is converted into pressure at the inlet—this is ram recovery. That higher inlet pressure (and the related slight increase in air density experienced by the compressor) allows more air to enter the engine and can raise the compressor inlet pressure, resulting in a bit more thrust. In short, ram air pressures created by velocity increase engine thrust, which is exactly what ram recovery describes.