Aviation Maintenance Terms beginning with N

NACA

National Advisory Committee for Aeronautics. This organization, dedicated to the technical development of aviation, has been superseded by NASA.

NACA cowling

A long-chord cowling used over a radial engine. The forward portion of this cowling has an aerodynamic shape that produces a forward pull, and the rear portion extends back to fair in with the fuselage. There is a narrow peripheral gap between the rear of the cowling and the fuselage for the cooling air to escape. Some NACA cowlings have controllable flaps over this opening to control the amount of cooling air that flows through the engine.

NASA

National Aeronautics and Space Administration.