Textron Inc.
Mast Lockout Systems for Tiltrotor Aircraft

Abstract:

A mast lockout system for a tiltrotor aircraft having a proprotor assembly. The system includes a mast coupled to and rotatable with the proprotor assembly. A proprotor gearbox having a proprotor gearbox housing is operable to transmit torque and rotation energy to the mast. A lock assembly has first and second lock members. The first lock member is coupled to and rotatable with the mast. The second lock member is coupled to the proprotor gearbox housing. The lock assembly has a first position in which the first and second lock members are disengaged, thereby allowing rotation of the proprotor assembly. The lock assembly has a second position in which the first and second lock members are engaged, thereby preventing rotation of the proprotor assembly. The lock assembly is actuatable between the first and second positions.