# NTSB SEA90IA042: Boeing 747-446B, Everett, WA, February 15, 1990

- Type: NTSB incident investigation
- Classification: Incident · No injuries · Incident investigation · Final report
- Date: February 14, 1990, 18:50 local (Feb 15, 1990, 01:50 UTC)
- Place: Everett, WA
- Coordinates: 47.979587, -122.200012 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=47.9796&lon=-122.2000&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 7 uninjured
- Status: Completed, report December 30, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 41132
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA90IA042
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41132/pdf
- Page: https://openairdocs.org/ntsb/SEA90IA042

## Probable cause

A BREAK FROM PRE-EXISTING INTERGRANULAR CRACKS WHICH LED TO A FRACTURE.

## Sequence of events

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

- Airframe/component/system failure/malfunction, landing - roll
  - landing gear,main gear strut - fractured (cause)

## Analysis

DURING THE LANDING ROLL, AT THE END OF A FLIGHT, THE PILOT REPORTED THAT THE EICAS DISPLAYED A CAUTION MESSAGE OF HYDRAULIC PRESSURE AND QUANTITY AND GEAR DOOR. THE PILOT ALSO NOTED THAT THE AIRPLANE WAS LISTING TO THE RIGHT. IT WAS LATER FOUND THAT THE RIGHT WING LANDING GEAR, OUTER CYLINDER AFT TRUNNION ARM BROKE. THE PART WAS METALLURGICALLY TESTED AND FOUND THAT THE TRUNNION FRACTURED AS A RESULT OF PRE-EXISTING INTERGRANULAR CRACKS.

## Aircraft

- Registration: UNREG (not matched to a registry record)
- Reported make and model: BOEING 747-446B
- Category: Airplane
- Engines: GE CF6-80C2B1F turbo fan
- Damage: Minor damage
- Flight: Part 91
- Registered owner: Boeing Commercial Airplanes
- Airworthiness certificate: Special, Special flight (Special)
- Departed: MWH, MOSES LAKE, WA
- Flight plan: IFR
- Airport: PAE, Paine Fld, runway 16R, 9,010 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 54; commercial, airline transport; airplane ratings: single-engine land, multi-engine land, single-engine sea, multi-engine sea; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: right; flight hours: 11,482 total, 228 in this make and model, 6,091 as pilot in command, 46 in the last 90 days, 17 in the last 30 days, 5 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Night/dark
- Wind: 120° at 12 knots
- Visibility: 25 statute miles
- Lowest ceiling: 6,000 ft broken
- Temperature: 30 °F, dew point 19 °F
- Altimeter: 30.00 inHg

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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