Fairchild SA227-AC, VH-UUN

The Metroliner III was departing Cooktown for Cairns. At about 250 ft above ground level the flight crew noticed that a fuel by-pass light had illuminated. The crew reported that they then retarded both engine power levers slightly in an attempt to extinguish the light. The left engine torque indications immediately began to fluctuate by about 5 percent but then increased to 20 percent. The left exhaust gas temperature and fuel flows were also fluctuating. The engine torque indications continued to surge, and the pilot-in-command elected to shut down the engine as a precautionary measure. The crew then notified air traffic control of their intention to return to the departure runway, where the aircraft made a single engine landing.

Subsequent trouble shooting determined that the engine problem was associated with a transient fault in the Single Red Line computer for the left engine. The computer was replaced, and the aircraft was returned to service without recurrence.

The company safety officer reported that he conducted an investigation into the incident and advised that, as the aircraft performance was not significantly impaired and because there was no indication of fire or catastrophic failure, it would have been more appropriate for the crew to continue the climb with both engines operating until a more detailed assessment of the situation could be made.

The occurrence brief is based on information obtained from the company's safety officer. The ATSB did not conduct an on-site investigation into the occurrence.