This is a revised text used for the Air Force ROTC program. The main part of the book centers on the discussion of the engines in an airplane. After describing the terms and concepts of power, jets, and rockets, the author describes reciprocating engines. The description of diesel engines helps to explain why these are not used in airplanes. The discussion of the carburetor is followed by an explanation of the lubrication system. The chapter on reaction engines describes the operation of jets, with examples of different types of jet engines. (PS)