An Electric V.P. Airscrew: The Curtiss Constant‐Speed Full‐Featuring Type with Electric and Manual Control

TRENDS in modern aeroplane design toward multi‐engined types super‐charged for high altitude operation have imposed new demands upon variable‐pitch airscrew equipment. To secure the best operating conditions with a minimum of attention from the pilot, constant speed control is essential. To meet the requirements of increased speed range, a wide operating range of blade angles is necessary. To prevent possible further damage to the engine and aeroplane due to “windmilling,” in the event of failure of one of the power plants, and to secure a maximum of performance from the remaining power, it is highly desirable that the airscrew be capable of attaining blade angles of 85 to 90 deg. or of being “feathered.” For maximum flexibility, the airscrew control should be independent of the engine. At all times, it is essential that the pilot should have ready means of selecting and controlling the type of operation desired.