GB657796A - Adjustment mechanism for helicopter stabilizing surface - Google Patents

Abstract

657,796. Helicopters. AUTOGIRO CO. OF AMERICA. Feb. 24, 1949, No. 5039. Convention date, Feb. 27, 1948. [Class 4] A helicopter is provided with a pivoted tailplane which is operable upon fore-and-aft movement of the pilot's control column to control translational flight, movement of the plane producing pitching moments resulting in the neutral or mid-point of the control column remaining substantially unchanged during hovering or translational flight. In the form shown, the control column 8, in addition to being connected to the cyclic pitch control mechanism 10, 11, carries an arcuate wiper arm 26 engageable with contacts 27, 28 to operate a reversible electric motor 18 controlling the tail-plane 12, and also carries an over-riding switch operated by a press-button 24 at the end of the column. If the aircraft is hovering and the column 8 is moved forwardly to initiate forward flight, upon actuating the button 24 the motor circuit is closed and the tail-plane moved to the position 12a. During its movement an increasing nose-down moment is produced, enabling the column 8 to be moved rearwardly, until the mid-position is again reached and the motor circuit opened. Upon release of the button 24 the column 8 may be moved to any position without moving the stabilizer plane 12. When reverting to the hovering condition the procedure is reversed, the column 8 being moved rearwardly with the button 24 depressed to return the surface 12 to its original position. The contact members 26, 27, 28 are so arranged that the column 8 may be moved through a small angle in either direction from the mid-position without the contacts 27, 28 being engaged by the member 26.