The advantages of variable pitch propellers over constant pitch propellers is presented along with different methods of varying the pitch. The technique of varying the shape of the propeller is presented as the most efficient one.

The connections between the cockpit and the control surfaces are examined. An examination of the pros and cons of using stick control, the problems of control in giant aircraft, an effort to find a substitute for these controls, and a proposed concept for mechanically operated gear are provided.

Report presenting a description of the autogiro, which is a flying machine built and designed in Spain. A history of the device and the reasons why it is safer and more stable than a typical aircraft are provided.

The development of more efficient control surfaces requiring less force to operate are presented. Some of the control surfaces explored include the De Havilland gear, Flettner rudder, and some other possible control methods.

Emphasized here is the desirability of using recording instruments in the investigation of the characteristics of airplanes with particular reference to the National Advisory Committee for Aeronautics (NACA) control force recorder. Given here are photographs, records, and a description of the instrument developed by NACA for investigations on different types of aircraft. Described here is an instrument for recording control forces.

Note presenting an investigation undertaken to answer the question of what cycle of heat phases should be selected for small high speed engines running on solid or airless injection with compression ignition, and what the relative proportions of the heat phases should be.

"The various speeds of an airplane can only be measured in horizontal flight, since there are no means for measuring the angle of ascent or descent. The measurements must be corrected for the density of the air. This is obtained by simultaneous pressure and temperature measurements during flight" (p. 1).

Discussed here is the suggested installation of the 'unbalanced' 8-cylinder VE-engine. The suggestion was that a flexible mounting be used instead of bolting the engine rigidly to the airplane structure. It was concluded that a flexible connection between the engine and the airplane is probably possible. A flexible connection primarily diminishes the vibrations due to inertia and, to a lesser degree, those due to torque variation. However, engines vibrate more when freely suspended than when rigidly mounted, and this vibration has a detrimental effect on all connections between the engine and the airplane. Therefore, in view of the relatively insignificant advantages which may be derived from the elastic suspension of the engine, the present rigid mounting is to be preferred. Vibration reduction can be achieved by incorporating in the fuselage as many of the rigid airplane parts as possible.