In 1978 a Gulf Air Tristar (about two years old) lost a nosewhel on departure from LHR. The crew had no knowledge until informed by ATC that the wheel had been found at LHR. The aircraft was enroute to BAH, and continued through the night. I was working in GF Maintrol at the time, and at about 0500 the Ops Manager called us to inform us that after much consideration he had given the aircraft permission to land. We wondered what plan B was. Anyway it landed without incident and taxied onto the stand. A NLG replacement was required as the axle had sheared off, and it is part of the strut on a Tristar.