Incident · 2017-06-03
What the record says
- Event date
- 2017-06-03
- Event type
- Incident
- Highest injury level
- No injuries
- Aircraft
- BOEING 737 7H4 (N765SW)
- Operating rule
- Part 121
- Operator
- SOUTHWEST AIRLINES, CO. Operator named in NTSB report
- Operated by (per NTSB report)
- SOUTHWEST AIRLINES CO
Probable cause
The failure the control alternator gearshaft, which disconnected the accessory gearbox from the rest of the engine and resulted in an uncommanded in-flight shutdown of the left engine and subsequent flight diversion. The control alternator gearshaft failed because of high cycle fatigue intergranular corrosion cracking. Contributing to the failure of the control alternator gearshaft were additional manufacturing processing steps to address part non-conformances that reduced its high cycle fatigue capability and potential change in vibratory environment since the last shop visit.
Source: NTSB case ENG17IA027Flight crew
No flight-crew details recorded in the NTSB accident database for this event.
Facts as the NTSB records them — GroundCheck adds no judgement. Preliminary records may be revised as the investigation proceeds.