delta hinge

plural delta hinges

1. aeronauticsOn rotorcraft, a hinge with its axis parallel to the rotor plane of rotation, which permits the rotor blades to flap.

   This could be varied to produce a delta hinge effect for equalizing lateral moments.

   1954, Eugene K. Liberatore, Rotary Wing Aircraft Handbooks and History: Convertible aircraft, page 39

   3 more examples

   Overtorque of the delta hinge bolt is reported to cause binding in the pitch change mechanism and failure of the tail rotor pitch change bearing.

   1969, Federal Aviation Administration, General aviation inspection aids, page 22

   The Kiowa has a two-bladed semi-rigid seesaw all metal main rotor and a two-bladed rigid delta hinge all metal tail rotor.

   2003, Harold Skaarup, Ohio Warbird Survivors 2003: A Handbook on where to find them, →ISBN

   You can get the same effect by offsetting the pitch change horn at the root of the blade (notice that the tip of the horn is in line with the extended delta hinge line in the picture).

   2007, Phil Croucher, Professional Helicopter Pilot Studies, →ISBN