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Multi-motored Airplanes, 1933


Level Flight

A helicopter's direction of movement is controlled by tilting the spinning rotor blades, the machine banking and rolling moving in the direction of right or left tilt, and climbing or descending in the direction of up or down tilt. Leveling the blades keeps the direction of movement to vertical only and power adjustment maintains a hovering position. Left or right turning is accomplished by altering the angle of the tail rotor which then acts like a rudder. The unique ability of a helicopter to fly backward is also controlled by tilt of the rotor blades.

The aim in flying a helicopter is to keep the power, controlled by the throttle, matching the requirements from directional movement of the machine and avoiding engine stalling. Each alteration of main rotor pitch calls for matching power to those rotors to keep the system stable.

For straight, level flying, the helicopter pilot must add foot movement to the hands' movement already occupied with tilt and throttle. A pair of foot pedals operate the tail rotor pitch (or angle), turning the machine to the left or right and at the same time compensating for torque and drift.

Pan American Brochure
Pan American Airways System Brochure, showing timetable of flights to South America, 1/1/1933 (2.3M) | Page 2 (3.5M) | Page 3 (3.2M) | Page 4 (3.0M) | Page 5 (3.2M) | Back Cover (1.7M)

S-40 Amphibion
Description of the Sikorsky S-40 Amphibion (3.4M) | Page 2 (3.0M) | Page 3 (3.1M) | Page 4 (2.1M)