Examination of the Main Landing Gear Wheel Bearings

During a routine departure from Melbourne aerodrome, the inner left main landing gear wheel separated from a B727 aircraft (registration VH-TXH) and was later recovered near the aerodrome perimeter fence. Preliminary examination showed that the outer axle bearing had failed, allowing the wheel hub to move axially outward over the retaining nut and off the stub axle (figure 1).