# Accident 19960701046109A: Saab 340B, Dallas, TX, July 1, 1996

- Type: FAA accident report (Accident/Incident Data System), as reported
- Date: July 1, 1996, 07:11 local time
- Place: Dallas, TX
- Airport: Dfw Airport
- Damage: Substantial damage
- Phase of flight: Climb
- Operating rules: Air carrier (Part 121)
- Operator: WWMA
- Location: 32.8932° N, 96.9689° W: Placed by OpenAirDocs from the FAA’s distance and direction from , within about a mile (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=32.8932&lon=-96.9689&mi=10
- Aircraft: N335AE (not matched to a registry record)
- Reported make and model: SAAB 340B
- Reported engine: GE CT79B
- People aboard: 15
- Fatal injuries: 0
- Pilot flight hours: 9,200 total, 2,000 in this make and model, 173 in the last 90 days
- NTSB investigation: [NTSB FTW96FA282](https://openairdocs.org/ntsb/FTW96FA282) (OpenAirDocs)
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/19960701046109A

## Narrative

As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^.

(.4)THE AIRPLANE DEPARTED RUNWAY 13L AND CLIMBED TO AN ALTITUDE OF APPROXIMATELY 400 FEET AGL WHEN THE FLIGHT CREW 'HEARD A LOUD BANG.' THE RIGHT ENGINE UPPER COWLING DEPARTED THE AIRPLANE, THE RIGHT ENGINE SHUT ITSELF DOWN, AND THE RIGHT PROPELLER AUTOMATICALLY FEATHERED.  THE FLIGHT CREW DECLARED AN EMERGENCY AND EXECUTED A SINGLE ENGINE LANDING WITHOUT FURTHER INCIDENT.  EXAMINATION OF THE AIRPLANE'S RIGHT CT7-9B TURBOPROP ENGINE REVEALED THAT THE STAGE 2 TURBINE DISK WAS MISSING AND THAT APPROXIMATELY ONE THIRD OF THE DISK WAS FOUND IN THE RIGHT LANDING LIGHT COMPARTMENT.  ONE END OF THE DISK FRAGMENT PROGRESSED THROUGH A COOLING AIR HOLE AND THERE WAS EVIDENCE OF A FATIGUE FRACTURE THAT HAD INITIATED FROM MULTIPLE ORIGINS ON THE INBOARD SIDE OF THE COOLING AIR HOLE.  RESEARCH REVEALED A LAYER OF DEFORMED MICROSTRUCTURE AND AN ASSOCIATED ZONE OF INCREASED DISK HARDNESS NEAR THE ORIGIN AREA OF THE FATIGUE CRACK.  TEST DISKS WERE DRILLED USING DULL AND WORN DRILL BITS WHICH RESULTED IN PLASTIC DEFORMATION AND INCREASED HARDNESS OF THE INNER DIAMETER HOLE SURFACES.  THE MANUFACTURER REPORTED THAT THE DEFORMED MICROSTRUCTURE CORRELATES TO A ZONE OF REDUCED FATIGUE PROPERTIES.

## The NTSB's investigation of this event (1)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB FTW96FA282](https://openairdocs.org/ntsb/FTW96FA282), Jul 1, 1996: Saab-Scania SF340B (N335AE), Dfw Airport, TX, substantial damage. Probable cause: The manufacturer's inadequate procedure for manufacturing the number two turbine disk.

From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record.

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