# NTSB DCA89IA066: Mcdonnell Douglas DC-10-40, N133JC, Denver, CO, August 10, 1989

- Type: NTSB incident investigation
- Classification: Incident · No injuries · Incident investigation · Final report
- Date: August 9, 1989, 18:18 local (Aug 10, 1989, 00:18 UTC)
- Place: Denver, CO
- Location: 39.7392° N, 104.9847° W: Placed by OpenAirDocs: center of Denver, CO, within about 7 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=39.7392&lon=-104.9847&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 254 uninjured
- Status: Completed, report October 7, 1992
- Report: Approved by Office Director
- NTSB office: Major Investigations Division
- Safety recommendations: Yes
- NTSB case key (mKey): 15912
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DCA89IA066
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/15912/pdf
- Page: https://openairdocs.org/ntsb/DCA89IA066

## Probable cause

FATIGUE FAILURE AND SEPARATION OF A FIRST-STAGE COMPRESSOR FAN BLADE.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Loss of engine power(total) - mech failure/malf, climb - to cruise
  - compressor assembly,blade - fatigue (cause)
  - inadequate quality control, other maintenance personnel (cause)
  - compressor assembly,blade - separation

## Analysis

WHILE CLIMBING THROUGH 38,000 FEET, THE AIRCRAFT EXPERIENCED AN UNCONTAINED FAN BLADE SEPARATION IN THE NO. 2 ENGINE. INVESTIGATION REVEALED THAT ONE OF THE FIRST-STAGE COMPRESSOR FAN BLADES (S/N EB2506) HAD SEPARATED ABOUT 8 INCHES ABOVE THE BLADE PLATFORM. FRAGMENTS FROM THE BLADE (#8) HAD EXITED THROUGH THE LEFT FAN COWL IN THREE PLACES AND HAD PENETRATED THE VERTICAL STABILIZER. THE BLADE SEPARATION STEMMED FROM A 0.34-INCH LONG FATIGUE CRACK THAT BEGAN IN A WELD ADJACENT TO A PATCH. THE FAN BLADE HAD BEEN PATCH-REPAIRED EARLIER, AND SUBJECTED TO FOUR NON-DESTRUCTIVE TESTS: X-RAY, FLUORESCENT PENETRANT, ULTRASONIC, AND EDDY CURRENT.

## Aircraft

- Registration: [N133JC](https://openairdocs.org/deregistered/N133JC-2007-05-03), registration cancelled 2007-05-03, S/N 46752, built 1972 (OpenAirDocs)
- Reported make and model: MCDONNELL DOUGLAS DC-10-40
- Registry model: [Douglas DC-10-40](https://openairdocs.org/model/douglas-dc-10-40) (registry code 3023508) (OpenAirDocs)
- Registry engine: [Pratt & Whitney JT9D-3A](https://openairdocs.org/engine/pratt-whitney-jt9d-3a) (registry code 52050, turbo-fan) (OpenAirDocs)
- Category: Airplane
- Engines: P&W JT9D-20J turbo fan
- Damage: Minor damage
- Flight: Part 121
- Registered owner: Northwest Airlines, Inc.
- Airworthiness certificate: Standard, Transport
- Last inspection: AAIP, July 28, 1989, 32 hours before
- Departed: LOS ANGELES, CA
- Destination: MINNEAPOLIS, MN
- Flight plan: IFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; airline transport; airplane ratings: multi-engine land; instrument ratings: airplane; medical: unknown, unknown

## Weather

- Conditions: Visual (VMC), Not reported

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.

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