# NTSB DCA86AA011: Boeing 747-136, Boston, MA, December 15, 1985

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Final report
- Date: December 15, 1985, 14:50 local (19:50 UTC)
- Place: Boston, MA
- Location: 42.4154° N, 70.9732° W: Placed by OpenAirDocs from NTSB’s distance and direction from GENERAL EDWARD LAWRENCE LOGAN INTL (BOS), within about a mile (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=42.4154&lon=-70.9732&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 269 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB office: Major Investigations Division
- Safety recommendations: Yes
- NTSB case key (mKey): 15849
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DCA86AA011
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/15849/pdf
- Page: https://openairdocs.org/ntsb/DCA86AA011

## Sequence of events

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

- Airframe/component/system failure/malfunction, approach - vfr pattern - final approach
  - flight control,flap attachment - failure,partial (contributing factor)
  - flight control,flap attachment - fatigue (cause)
  - acft/equip,inadequate airframe, manufacturer (contributing factor)
  - insufficient standards/requirements,manufacturer, manufacturer (contributing factor)
  - maintenance - inadequate, manufacturer (contributing factor)
  - maintenance,inspection - inadequate, manufacturer (contributing factor)

## Analysis

APRX 16 FT OF THE LEFT INBOARD TRAILING EDGE FLAP SEPARATED WHILE THE ACFT WAS ON FINAL APCH TO LAND. THE APCH AND LANDING WERE COMPLETED WITHOUT FURTHER INCIDENT. INVESTIGATION REVEALED 5 OF THE 8 BOLTS WHICH HOLD THE NO. 3 FLAP TRACKFORWARD ATTACH FITTING TO THE WING SHOWED SIGNS OF FATIGUE AND THE 3 REMAINING BOLTS SHOWED OVERLOAD TYPE FAILURES. NO INSPECTION REQUIREMENTS FOR THE FORWARD ATTACHMENT BOLTS WERE REQUIRED BY BOEING AT THE TIME OF THE ACCIDENT.

## Aircraft

- Registration: GAWNE (not matched to a registry record)
- Reported make and model: BOEING 747-136
- Category: Airplane
- Serial number: 19765
- Airframe hours: 55667
- Engines: P&W JT9D-7A 46250 lbs thrust turbo fan
- Damage: Substantial damage
- Flight: Part 129
- Registered owner: British Airways
- Airworthiness certificate: Standard, Transport
- Last inspection: AAIP, October 20, 1985, 700 hours before
- Departed: LHR, LONDON, OF
- Flight plan: IFR
- Airport: BOS, Logan Int'L, runway 22L, 10,005 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 49; airline transport; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 6,481 total, 645 in this make and model, 38 in the last 30 days, 7 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 230° at 14 knots
- Visibility: 15 statute miles
- Lowest ceiling: none
- Temperature: 30 °F, dew point 10 °F
- Altimeter: 29.00 inHg
- Observed at: BOS, 4 nm away

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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