Propeller pitchlock un-locking device

A pitch unlock mechanism for a propeller system comprising:

• a pitch unlock housing;
• a pitch unlock piston disposed in the pitch unlock housing in operably communication with a pitch lock piston of the propeller system;
• and
• a fitting extending through the propeller system to the pitch unlock housing;
• wherein introduction of fluid flow into the pitch unlock housing through the fitting urges the pitch unlock piston into contact with the pitch lock piston to move the pitch lock piston away from a locked position thereby unlocking the pitch of the plurality of propeller blades.

A method of adjusting a pitch of a plurality of propeller blades of a propeller system comprising:

• locking a pitch of the propeller blades by moving a pitch lock piston of a pitch control system to a locked position via a failure of the pitch control system;
• pressurizing a pitch unlock housing by introducing a flow of fluid from an auxiliary supply into the pitch unlock housing;
• urging a pitch unlock piston into contact with the pitch lock piston via the pressurization;
• moving the pitch lock piston from the locked position to an unlocked position via the contact;
• manually pitch-adjusting the plurality of propeller blades;
• and
• depressurizing the pitch unlock housing to return the pitch lock piston to the locked position.