Engine Hot Section Deterioration and Engine Condition Trend Monitoring (ECTM) - Service Difficulty Alert

AL 2009-08
27 October 2009

The in-flight failure of a Pratt and Whitney Canada (P&WC) PW150A engine prompted an operator to conduct unscheduled Hot Section Inspections on the rest of their engines. The resulting unscheduled inspections revealed several engines within the operator’s fleet to be damaged beyond limits, particularly in the high-pressure turbine shroud area, resulting in their removal from service.

The authority of the occurrence country, Transport Canada and P&WC has investigated the original occurrence engine. Hot section distress was noted in several areas. A review of the trend data revealed an increasing upward trend in inter-turbine temperature (ITT) and gas generator speed.

This Alert is issued to bring to the attention of all operators and maintainers, utilizing Engine Condition Trend Monitoring (ECTM) systems for the on-condition maintenance of their engine fleet, the importance of diligently following relevant recommendations published by the manufacturer.

Thoroughly investigating and understanding any change in trend readings is paramount to a successful program. Where any doubt exits in the interpretation of said recommendations or identified adverse trends, it is important to communicate with engine design organization for clarification and guidance.

P&WC has issued a service information letter (SIL)150-031 to address this subject, as well as to clarify the interpretation and recommendations particular to their product.

For further information regarding this SDA, contact the engine manufacturer, a Transport Canada Centre or Mr. Paul Jones, Continuing Airworthiness, Ottawa, telephone 613 952-4357 or by email at CAW WEB Feedback@tc.gc.ca

For Director, National Aircraft Certification

Derek Ferguson
Chief, Continuing Airworthiness

Note:  For the electronic version of this document, please consult the following Web address: https://tc.canada.ca/en/aviation/aircraft-airworthiness/aircraft-certification