The bifilar pendulum absorber is used to reduce the inplane longitudinal and lateral excitation forces and it is mounted to the rotor hub of a helicopter.

• 双线摆式吸振器是位于直升机旋翼旋转平面内用来吸收该平面内桨毂纵、横向激振力的动力吸振器,能随旋翼转速而调谐。