A shrink shock strut assembly for retractable aircraft landing gear is disclosed which includes an elongated strut cylinder, an elongated strut piston coaxially mounted for reciprocal movement within the strut cylinder between a shrunk condition when the landing gear is retracted into a wheel well of an aircraft and a fully extended condition when the landing gear is deployed from the wheel well for landing the aircraft, and a blocking mechanism operatively associated with the strut cylinder and mounted for movement into a blocking position with respect to the strut piston, when the landing gear is retracted within the wheel well, to prevent axial movement of the strut piston into the fully extended condition within the wheel well.