What was found
AFTER DEPARTURE FROM LBB, PILOT REPORTED LOW PRESSURE LIGHT FOR RIGHT GEARBOX ILLUMINATED. THE CAPTAIN OBTAINED CLEARANCE AND ELECTED TO SHUT DOWN RIGHT ENGINE AND RETURN TO THE LBB AIRPORT. LANDING WAS MADE WITHOUT FURTHER INCIDENT. M/C CONTACT LBB AERO, A CONTRACT MAINTENANCE FACILITY. MECHANIC INSPECTED THE RIGHT GEARBOX ASSY. THE MECHANIC REPORTED HE FOUND A LOOSE B-NUT ON THE ROOTS BLOWER THAT WAS SAFETIED, BUT WAS NOT TIGHT. HE TIGHTENED THE B-NUT AND RE-SAFETIED IT, SERVICED THE GEARBOX WITH TWO QUARTS OF OIL. THE ENGINE WAS RUN, THE GEARBOX WAS RE-INSPECTED AND FOUND TO BE DRY. AIRCRAFT WAS RETURNED TO SERVICE. (X)