What creates the pressure of the air in a pressure cowling?

• A. The engine's exhaust pressure.
• B. The forward velocity of the airplane as air enters openings in the cowling and flows into the engine compartment.
• C. The oil pressure.
• D. Ambient air pressure at altitude.

Answer: (B)

Dynamic ram air from the aircraft’s forward motion forces air into the openings of the cowling and through the engine compartment, creating the pressure inside the cowling. This ram pressure increases with speed and provides the airflow needed for cooling. It’s not produced by exhaust, oil pressure, or simply ambient atmospheric pressure at altitude.