# NTSB SEA91IA219: Boeing 747-151, N604US, Seattle, WA, August 22, 1991

- Type: NTSB incident investigation
- Classification: Incident · Minor injuries · Incident investigation · Final report
- Date: August 22, 1991, 16:04 local (23:04 UTC)
- Place: Seattle, WA
- Coordinates: 47.439151, -122.280639 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=47.4392&lon=-122.2806&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 11 minor, 376 uninjured
- Status: Completed, report February 8, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 41348
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA91IA219
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41348/pdf
- Page: https://openairdocs.org/ntsb/SEA91IA219

## Probable cause

A FIRE IN THE NUMBER 4 ENGINE, RESULTING FROM A FUEL LEAK AT THE MAIN FUEL CONTROL UNIT, DUE TO IMPROPER MAINTENANCE BY UNKNOWN/UNDETERMINED PERSON. THE L5 EMERGENCY EXIT FAILED TO OPERATEE DUE TO A BROKEN PLASTIC PULLEY GUARD IN THE SLIDE RELEASE MECHANISM.

## Sequence of events

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

- Fire, climb - to cruise
  - fuel system,fuel control - leak (cause)
  - maintenance - improper, other maintenance personnel (cause)

## Analysis

THE NO 4 ENGINE CAUGHT FIRE DURING CLIMB AFTER TAKEOFF AND THE CREW ACTIVATED THE ENGINE FIRE EXTINGUISHER SYSTEM, DUMPED FUEL, AND RETURNED TO THE ARPT FOR AN EMERGENCY LANDING. THE NO 4 ENGINE FIRE AND A GRASS FIRE AT THE RWY T/D ZONE WERE EXTINGUISHED BY ARPT CFR CREW. AN EMERGENCY EVAC WAS CONDUCTED FROM THE LEFT SIDE AFTER THE ACFT STOPPED ON THE RWY. THE L5 EMERGENCY DOOR AND SLIDE FAILED TO DEPLOY FOR THE EVAC. EXAM OF THE ENGINE REVEALED EVIDENCE OF FUEL LEAK FROM THE MAIN FUEL CONTROL UNIT.

## Aircraft

- Registration: [N604US](https://openairdocs.org/deregistered/N604US-1994-08-02), registration cancelled 1994-08-02, S/N 19781 (OpenAirDocs)
- Reported make and model: BOEING 747-151
- Registry model: [Boeing 747-151](https://openairdocs.org/model/boeing-747-151) (registry code 1384891) (OpenAirDocs)
- Category: Airplane
- Serial number: 19781
- Engines: P&W JT9D-7A 46500 lbs thrust turbo fan
- Damage: Minor damage
- Fire: In-Flight
- Flight: Part 121
- Operator: Northwest Airlines, Inc
- Airworthiness certificate: Standard, Transport
- Departed: KSEA, SEATTLE, WA
- Destination: RJAA, TOKYO, OF
- Flight plan: IFR
- Airport: SEA, Seatac, runway 34R, 11,900 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 58; airline transport; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: left; flight hours: 22,700 total, 2,700 in this make and model, 150 in the last 90 days, 50 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 220° at 8 knots
- Visibility: 50 statute miles
- Lowest ceiling: none
- Temperature: 79 °F, dew point 55 °F
- Altimeter: 30.00 inHg
- Observed at: SEA

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Incident 19910822046199I](https://openairdocs.org/incident/19910822046199I), Aug 22, 1991: Boeing 747151, Seattle, WA, Minor damage. Fire in NR4 engine on climb. Returned. Landed safely. Evacuated passengers. Number 5L slide did not operate.

## Other investigations on N604US (2)

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 NYC75AN065](https://openairdocs.org/ntsb/NYC75AN065), Nov 21, 1974: Boeing 747 (N604US), Jamaica, NY, minor damage
- [NTSB MIA71IM099](https://openairdocs.org/ntsb/MIA71IM099), May 20, 1971: Boeing 747 (N604US), Miami, FL, incident, no damage

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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