alpha hinge

noun

alpha hinge

noun

1

Aeronautics, Aerospace, Business, Engineering, Natural sciences, Physical sciences On rotorcraft, a hinge perpendicular to the plane of rotor rotation about which the blades trail or lag.

Similarly, as a blade with an alpha hinge lags through an angle §, ...1953, Daniel Otto Dommasch, Elements of Propeller and Helicopter Aerodynamics, page 129:
When rotor goes to autorotation, an inclined alpha hinge provides automatic change of blade pitch to three degrees as the shaft stops rotating.1958, Aviation Week and Space Technology - Volume 69, page 226:

1 more example

When flap and lag hinge inclination was introduced on the autogyro rotors, the inboard (flap) hinge was designated the “delta hinge,” and the outboard (lag) hinge designated the “alpha hinge.”2013, Wayne Johnson, Rotorcraft Aeromechanics, →ISBN, page 218:

Entry derived from the Wiktionary, under licence CC BY-SA 4.0 — list of authors.