Component Failure Analysis of J69-T-25A Engine

Methodology

The defects were collected from Log Books of engines for last two and half year (30 months). This data selection was done intentionally, with the aim to forecast and suggest remedial measures for remaining six months of Year 2011 through data analysis. Hours from last inspection and total operating life of top ten failed components was also collected from Log Books. The collected data was based upon following information:

• 1.

  Date on which defect was reported.

• 2.

  Defect category and nature.

• 3.

  Root cause identifying defective component.

• 4.

  Reason for component failure.

Total failures for each year were calculated. All scheduled and unscheduled engine removals were taken into consideration and in total 32 different components were identified. Top ten failed components were selected for analysis. The factors, affecting performance of components or contributing towards failure of component, like operating hours and operating conditions were used for failure analysis. During component failure analysis flight hours, schedule, and unscheduled removals cannot be over looked. Any failure during schedule inspection is expected that is the reason for schedule inspection after specified interval, whereas unscheduled removal is the major stakeholder for component failure analysis. The unscheduled removals help to decide component life, remedial measures, redefining inspection intervals, One Time Inspections (OTIs) and other steps to arrest the trend.

Identification Of Defective Components

The Log Books of the engine were reviewed. The year wise data for scheduled removals and unscheduled removals was segregated. Figure 1 describes the year wise schedule and unscheduled removals, whereas Figure 2 describes the total flying for the year during which failures occur.

Figure 1.

Year wise unsch, sch, and total removals