Incident Summary
While in cruise flight, the flight crew observed a master caution light that indicated a loss of right hydraulic system pressure and hydraulic fluid. Following the appropriate checklist, the crew attempted to manually extend the main and nose landing gears using the alternate extension control lever. The main landing gears extended and locked into place, but the nose landing gear did not extend. The aircraft was subsequently landed with the nose landing gear in the retracted position.
Inspection Findings
Initial inspection of the aircraft revealed that a B-nut attached to the check valve on the rudder power hydraulic shut-off valve had become separated from the valve, resulting in a complete loss of right hydraulic system quantity and pressure. Examination of the hydraulic tube, including the B-nut and check valve, did not reveal any abnormalities. Additionally, inspection of the cockpit showed that the landing gear handle was in the stowed position. A placard on the alternate landing gear extension lever stated, "Pull up forcibly Full Stroke."
The aircraft was subsequently placed on jacks, and maintenance personnel successfully extended the nose landing gear. The alternate gear extension control system was inspected and no defects were noted.