A pivoting connection on a helicopter's main rotor hub aligned parallel to the plane of rotation. It permits individual rotor blades to flap vertically as they spin, compensating for the unequal lift generated by the advancing and retreating blades during forward flight.
Heard on the job
The inspection revealed excessive wear on the delta hinge bearings.
Also heard as
- flapping hinge
Related terms
Alpha hinge
A mechanical joint in a helicopter rotor hub that allows the blade to move back and forth in the plane of rotation.
Helicopter
A rotorcraft that generates lift and thrust from engine-driven overhead rotors.
Lead-lag
The horizontal back-and-forth movement of a helicopter rotor blade as it spins.