What was found
OXC/GON - ON CLIMB-OUT AT APPROX 3,000 FEET, THE RIGHT OIL PRESSURE LIGHT ILLUMINATED FOLLOWED BY THE OIL PRESSURE DECREASING TOWARDS ZERO. THE ENGINE WAS SHUT DOWN AND ACFT RETURNED TO OXC, LANDED WITHOUT INCIDENT. INVESTIGATION REVEALED THE JET CLEAN-OUT OIL PLUG ON THE TRANSFER GEARBOX HAD COME LOOSE AND ALLOWED OIL TO LEAK. REPLACED O-RING, RESECURED PLUG WITH A NEW LOCKNUT. C/W INSTRUCTIONS ON FAX TRANSMISSION DATED 7-28-00. AIRCRAFT RETURNED TO SERVICE. (X)