On 23 December 2005 at about 1745 South Australian Summer Time, a British Aerospace Plc, J32, Jetstream aircraft was being operated on a scheduled passenger service from Mt Gambier to Adelaide in South Australia. The crew reported that during cruise flight at flight level (FL) 120 and in a shallow right turn, about 93 km east of Adelaide, the right engine briefly surged twice and then stopped.
After landing at Adelaide, the TPE331-12UHR-702H engine, serial number P66397C, was removed from the aircraft and forwarded to the manufacturer in the US for failure examination. The report of that engine examination indicated that the P/N 3103589-1 gear had a separated section of one gear tooth and several other damaged teeth. A metallurgical examination of the damaged components and the metal fragments found in the gearbox showed that there had been significant heavy wear of the mating surfaces of the spur gear teeth of both gears. The report further stated that experience had shown that the mating of a new or different gear, and a worn gear can accelerate tooth wear and lead to tooth fatigue cracking. In this instance the smearing of the separated surfaces and the damage sustained by the components precluded an assessment of whether the failure was due to fatigue. The report also indicated that, 'In the absence of an identified fatigue origin, there is also the possibility that a foreign object may have entered the gear mesh and overloaded a tooth'.
The engine manufacturer advised that they have submitted a Publication Change Request (PCR 029601) to the Inspection and Repair Manual 72-IR-15 specifically requiring an inspection for wear of the P/N 3103590-2 gear. That change is expected to be issued in late 2007.
|Date:||23 December 2005||Investigation status:||Completed|
|Location:||93km E Adelaide, VOR|
|State:||South Australia||Occurrence type:||Engine failure or malfunction|
|Release date:||17 May 2007||Occurrence class:||Technical|
|Report status:||Final||Occurrence category:||Incident|
|Highest injury level:||None|
|Aircraft manufacturer||British Aerospace PLC|
|Type of operation||Air Transport Low Capacity|
|Damage to aircraft||Nil|
|Departure point||Mt Gambier, SA|
|Role||Class of licence||Hours on type||Hours total|