Gimbal lock hook systems for rotorcraft

A tiltrotor aircraft comprising:

• a fuselage;
• a wing coupled to the fuselage;
• and
• a propulsion assembly rotatably coupled to the wing, the propulsion assembly comprising:
• a mast;
• a proprotor hub assembly coupled to the mast and having a gimballing degree of freedom relative to the mast, the proprotor hub assembly including first and second hook receivers;
• and
• a gimbal lock positioned about the mast, the gimbal lock including a locking ring and first and second gimbal lock hooks;
• wherein, the gimbal lock is movable between a disengaged position and an engaged position relative to the proprotor hub assembly, the gimbal lock enabling the gimballing degree of freedom in the disengaged position and disabling the gimballing degree of freedom in the engaged position;
• and
• wherein, the gimbal lock hooks are hooked to the hook receivers in the engaged position to secure the locking ring to the proprotor hub assembly.