As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LANDING GEAR RELEASED IN FLIGHT, RECYCLED GEAR WOULD'NT STAY LOCKED UP. RETURNED TO PANC FOR UNEVENTFUL LANDING. REPLACED LANDING GEAR SELECTOR VALVE, LEAK CHECKED AND OPS CHECKED NORMAL PER MM. AIRCRAFT RELEASED FOR TEST FLIGHT ONLY. VENDER REPORTED ERRATIC OPERATIONS, O-RINGS HAD PERMANENT SET, FOREIGH MATERIAL LODGED IN LAP ASSY. (M)