Loss of control involving Saab SF-340A, Devonport, Tasmania, VH-EKT, on 1 July 1992

On 1 July 1992, SAAB SF-340A, VH-EKT, was engaged on a scheduled passenger service from Melbourne, Victoria to Devonport, Tasmania. During the flight, the crew experienced difficulty in controlling the right propeller RPM. When the aircraft landed at Devonport, directional control was lost.

The aircraft departed the runway and ran through a ditch in soft, muddy ground. The aircraft sustained substantial damage but there were no injuries to passengers or crew. The investigation revealed that a severe asymmetric thrust condition developed after landing when reverse thrust was selected but the right propeller remained at a positive blade angle.

The report concludes that the right propeller control unit was defective, due to internal oil leakage across the feathering solenoid valve. As a result, the propeller failed to respond normally to pilot control input.