On 14 January 2008 the pilot of a single-engine Cessna Aircraft Company 208 conducted a successful forced landing back onto the departure runway after the aircraft's engine failed. The flight, with six passengers onboard, had earlier departed Townsville, Qld on a private Instrument Flight Rules (IFR) flight to Mt. Isa.
The evidence showed that the failure of the engine was precipitated by the fracture and separation of a single blade from the compressor turbine (CT) disc. The gross mechanical interference caused by the release of that blade into the confines of the turbine section contributed to the subsequent forced fracture of the other CT blades and the downstream migration of blade debris. The remainder of the internal engine damage was identified as secondary damage as a result of that debris.
Damage to the area of crack initiation limited the extent of examination such that the root cause of fatigue initiation could not be established with certainty. However, from the available evidence, it was considered likely that the crack initiated at a localised area of stress concentration, such as may have arisen from the passage of foreign object debris through the engine, from handling or tooling damage sustained during a prior maintenance activity, or from the effects of an isolated blade casting anomaly that was not evident to the examination.
|Date:||14 January 2008||Investigation status:||Completed|
|Time:||1035 EST||Investigation level:||Complex - click for an explanation of investigation levels|
|State:||Queensland||Occurrence type:||Engine failure or malfunction|
|Release date:||05 June 2009||Occurrence class:||Technical|
|Report status:||Final||Occurrence category:||Serious Incident|
|Highest injury level:||None|
|Aircraft manufacturer||Cessna Aircraft Company|
|Type of operation||Private|
|Damage to aircraft||Nil|
|Departure point||Townsville, Qld|
|Destination||Mount Isa, Qld|
|Role||Class of licence||Hours on type||Hours total|