# NTSB LAX90FA061: Boeing 737-204, N198AW, Tucson, AZ, December 31, 1989

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Field investigation · Final report
- Date: December 30, 1989, 19:01 local (Dec 31, 1989, 02:01 UTC)
- Place: Tucson, AZ
- Coordinates: 32.150516, -110.929687 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=32.1505&lon=-110.9297&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 10 minor, 123 uninjured
- Status: Completed, report October 7, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 26604
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX90FA061
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/26604/pdf
- Page: https://openairdocs.org/ntsb/LAX90FA061

## Probable cause

FAILURE OF THE OPERATOR'S MAINTENANCE PERSONNEL TO DETECT AN ELECTRICAL WIRE WHICH HAD CHAFED AGAINST A HYDRAULIC LINE AND WHICH EVENTUALLY ARCED CAUSING A LEAK IN THE HYDRAULIC LINE AND SUBSEQUENT FIRE AND HYDRAULIC SYSTEM FAILURE. IN ADDITION, PREVIOUS WEAR OF CHECK VALVES IN THE BACKUP HYDRAULIC SYSTEMS PREVENTED THE AIRPLANE FROM STOPPING ON THE RUNWAY. A CONTRIBUTING FACTOR WAS THE AIRPLANE MANUFACTURER'S INADEQUATE GUIDANCE FOR MAINTAINING THE HYDRAULIC COMPONENTS.

## Sequence of events

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

- Fire, descent - normal
  - electrical system,electric wiring - chafed (cause)
  - maintenance,inspection - inadequate, company maintenance personnel (cause)
  - electrical system,electric wiring - arcing (cause)
  - hydraulic system,line - leak (cause)
  - hydraulic system - fire
- Airframe/component/system failure/malfunction, approach - vfr pattern - downwind
  - fluid,hydraulic - exhaustion (cause)
  - hydraulic system - failure,total
- Overrun, landing - roll
  - thrust reverser,accumulator - worn (cause)
  - landing gear,normal brake system - worn (cause)
  - aircraft/equipment inadequate, manufacturer (contributing factor)
- On ground/water collision with object, landing - roll
  - object - other

## Analysis

DURING APPROACH, A FIRE ERUPTED IN THE WHEEL WELL OF THE 22-YR OLD AIRPLANE. THE FIRE BURNED THRU THE HYDRAULIC LINES RENDERING THE A, B, & STANDBY HYD SYSTEMS INOP. THE CREW LANDED THE AIRPLANE USING THE EMERGENCY MANUAL REVERSION FLIGHT CONTROL SYSTEM. HOWEVER, THE AIRPLANE WAS UNABLE TO STOP ON THE RUNWAY BECAUSE OF THE PREVIOUS FAILURES OF THE CHECK VALVES IN THE BACKUP HYD ACCUMULATOR PRESSURE SYSTEMS FOR THE #2 THRUST REVERSER AND THE INBOARD PAIR OF WHEEL BRAKES. DURING THE 2 MIN ROLLOUT, THE AIRPLANE TRAVERSED 14,000 FT, OVERRAN THE RWY END, AND COLLIDED WITH A CONCRETE STRUCTURE WHICH COLLAPSED THE NOSE GEAR. THE AIRPLANE HAD RECENTLY UNDERGONE A 'C' CHECK DURING WHICH THE OPERATOR'S MECHANICS FAILED TO OBSERVE & REPAIR AN ELECTRIC WIRE WHICH HAD BEEN CHAFING AGAINST A HYD LINE. ON THE ACCIDENT FLT THE ENERGIZED WIRE ARCED, PUNCTURED THE LINE, & IGNITED THE ESCAPING HYD FLUID. THE HYD CHECK VALVES HAD FAILED EARLIER DUE TO MECHANICAL WEAR.

## Aircraft

- Registration: [N198AW](https://openairdocs.org/deregistered/N198AW-1993-12-07), registration cancelled 1993-12-07, S/N 19710 (OpenAirDocs)
- Reported make and model: BOEING 737-204
- Registry model: [Boeing 737-204](https://openairdocs.org/model/boeing-737-204) (registry code 1384458) (OpenAirDocs)
- Category: Airplane
- Serial number: 19710
- Airframe hours: 62466
- Engines: P&W JT8D-9A 14500 lbs thrust turbo fan
- Damage: Substantial damage
- Fire: Both
- Flight: Part 121
- Operator: America West Airlines, Inc.
- Registered owner: Aviation Sales Company, Inc.
- Airworthiness certificate: Standard, Transport
- Departed: PHX, PHOENIX, AZ
- Destination: TUS, TUCSON, AZ
- Flight plan: IFR
- Airport: TUS, Tucson Int'L, runway 29R, 10,994 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 33; airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: left; toxicology performed; flight hours: 10,600 total, 3,970 in this make and model, 8,290 as pilot in command, 217 in the last 90 days, 58 in the last 30 days, 6 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Night/dark
- Wind: 260° at 9 knots
- Visibility: 30 statute miles
- Lowest ceiling: none
- Temperature: 50 °F, dew point 39 °F
- Altimeter: 29.00 inHg
- Observed at: TUS

## FAA reports on this event (1)

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

- [Accident 19891230054269A](https://openairdocs.org/incident/19891230054269A), Dec 30, 1989: Boeing 737204, Tucson, AZ, Substantial damage. Fire in wheel well on downwind. Burned hydraulic lines. Overran runway. Electric lines shorted on hydraulic line.

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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