Aviation safety issues and actions
Safety Advisory Notice issued to: Federal Aviation Administration
|Date issued:||13 August 1999|
|Safety action status:||Closed|
|Background:||Why this Safety Advisory Notice was developed|
The Federal Aviation Administration should note the safety
deficiency identified in this document and take appropriate action
as considered necessary.
As a result of investigation into this occurrence, the Bureau simultaneously issues the following interim recommendations and safety advisory notice:
The Bureau of Air Safety Investigation recommends that the engine manufacturer AlliedSignal audit the process employed to manufacture TPE 331 turbine wheel knife-edged seals to determine those factors that may lead to excessive variations in slot corner radii.
The Bureau of Air Safety Investigation recommends that the engine manufacturer AlliedSignal determine the sensitivity of turbine wheel seals to the initiation of fatigue cracks from slot corners, as a function of slot corner radii.
The Bureau of Air Safety Investigation recommends that the engine manufacturer AlliedSignal consider, during engine design and the formulation of continuing airworthiness instructions, the possibility that turbine wheel seal fatigue failure may result in hazardous modes of engine failure.
The Bureau of Air Safety Investigation recommends that the Civil Aviation Safety Authority Australia conduct an audit of that part of the aviation safety system that establishes the operational history of life-limited components, to establish why the operational history of second-stage turbine wheel, p/n 868272-1, s/n P03214C, could not be determined with certainty.
|Date issued:||15 September 1999|
|Response from:||Federal Aviation Administration (FAA)|
The office of accident investigation is in receipt of your
recommendations concerning "TPE 331 Turbine Wheel".