In-flight shutdown, VH-QOA, 84 km north of Lockhart River Aerodrome, Queensland, on 20 June 2008

On 20 June 2008, a Bombardier DHC-8-402 aircraft, registered VH-QOA, with four crew and 59 passengers on board, departed Horn Island for Cairns, Queensland on a scheduled passenger flight. During the climb, the right propeller electronic control (PEC) caution light illuminated with an associated right propeller overspeed warning. The right engine was shut down in accordance with the operator's Quick Reference Handbook and the crew diverted the aircraft to Weipa.

During the approach to Weipa, the aircraft's right hydraulic system failed requiring the landing gear to be manually lowered. Due to the loss of hydraulic system services, the nosewheel steering was not available and the aircraft required ground crew assistance to tow the aircraft to the parking area.

As a result of a number of similar occurrences experienced by international and domestic operators, the propeller manufacturer developed a number of software changes which, when introduced, will allow the continued operation of an engine by the crew after the primary propeller speed signal is lost. The aircraft operator intends incorporating that modification into its DHC-8 fleet once training and other resource considerations are satisfied.

In addition, the aircraft manufacturer has incorporated a modification in the aircraft to ensure that the power transfer unit is started before the loss of the No. 2 hydraulic system pressure.