Canadian Forces Experience with Turbofan HCF - Case Study
Abstract
High Cycle Fatigue (HCF) cracking of a Canadian Forces (CF) turbofan engine fuel tube resulted in a six year, multinational effort to identify the root cause and to ultimately develop and implement a solution. The second of three fuel tube failures experienced by the CF during this timeframe resulted in an engine fire that caused significant damage to a military aircraft, underlining the seriousness of the issue at hand. With HCF identified as the mechanism of failure, efforts focused on vibration input to the fuel tube during engine operation. An experiment was developed to instrument an in-service fuel tube and perform comprehensive flight tests to quantify the strains experienced by the tube and identify vibration frequencies that required mitigation in order to eliminate HCF failures. A damper bracket was developed to shift the modal response of the fuel tube away from damaging frequencies experienced in-flight. The prototype bracket then required the addition of an adjustable feature that would allow it to accommodate slight variability in the location of mounting points from engine to engine. In addition, modification of some existing hardware was also required in order to implement the final solution. Production damper brackets were installed on all in-service engines, and to date have prevented any further fuel tube failures.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 2005
- Accession Number
- ADA469566
Entities
People
- Corey Kinart
- Pierre Theriault