Incident · 2006-06-02
What the record says
- Event date
- 2006-06-02
- Event type
- Incident
- Highest injury level
- No injuries
- Aircraft
- Boeing 767-223(ER) (N330AA)
- Operating rule
- UNK
- Operator
- AMERICAN AIRLINES, INC. Operator named in NTSB report
- Operated by (per NTSB report)
- AMERICAN AIRLINES INC
Probable cause
The HPT stage 1 disk failed from an intergranular fatigue crack because of GE's inadequate design of the CF6-80 series HPT stage 1 disk. The inadequate design of the disk resulted in a high stress area in the blade slot bottom aft corner that was at or nearly at the material's capability so that there was no damage tolerance such that a small dent could cause a crack to initiate and propagate to failure. Contributing to the disk's failure was the FAA's failure to mandate an accelerated inspection schedule after a previous CF6-80A uncontained HPT stage 1 disk failure had occurred and after other CF6-80A HPT disks had been found during routine overhaul to have cracks in the blade slot bottom aft corners.
Source: NTSB case ENG06IA018Flight crew
Flight-crew details for this event aren't in the NTSB database extract we hold (its coverage starts with 2008 events) — a gap in our data, not an absence of crew.
Facts as the NTSB records them — GroundCheck adds no judgement. Preliminary records may be revised as the investigation proceeds.