# NTSB SEA88IA108: Boeing 727-200, N308AS, Seattle, WA, June 13, 1988

- Type: NTSB incident investigation
- Classification: Incident · Minor injuries · Incident investigation · Final report
- Date: June 12, 1988, 22:17 local (Jun 13, 1988, 05:17 UTC)
- Place: Seattle, WA
- Coordinates: 47.300323, -122.310119 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=47.3003&lon=-122.3101&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 7 minor, 81 uninjured
- Status: Completed, report June 7, 1989
- Report: Approved by Office Director
- NTSB case key (mKey): 40743
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA88IA108
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/40743/pdf
- Page: https://openairdocs.org/ntsb/SEA88IA108

## Sequence of events

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

- Loss of control - on ground/water, landing - roll
  - thrust reverser,door - fatigue (cause)
  - thrust reverser,door - failure,partial (cause)
  - thrust reverser - asymmetrical (cause)
  - directional control - not maintained, pilot in command (contributing factor)
  - remedial action - improper, pilot in command (contributing factor)
  - inadequate training(emergency procedure(s)), company/operator management (contributing factor)
  - information unclear, manufacturer (contributing factor)
- On ground/water collision with object, landing - roll
  - object - runway light

## Analysis

AFTER THE MAIN GEAR TOUCHED DOWN, THRUST LEVERS WERE PLACED IN THE IDLE REVERSE POSITION. ONCE THE AIRCRAFT'S NOSE GEAR CONTACTED THE RUNWAY, BRAKING AND FULL REVERSE THRUST WAS APPLIED. THE AIRCRAFT STARTED TO DRIFT TO THE LEFT OF THE RUNWAY CENTERLINE. THE PILOT APPLIED ASYMMETRICAL BRAKING WITH NO CHANGE IN DIRECTIONAL CONTROL. THE PILOT THEN COMBINED THE USE OF ASYMMETRICAL BRAKING WITH ASYMMETRICAL REVERSE THRUST. AS A FINAL EFFORT TO PREVENT THE AIRCRAFT FROM DEPARTING THE RUNWAY, THE CAPTAIN USED THE TILLER. THE AIRCRAFT CAME TO REST ON A GRASSY AREA BETWEEN THE PARALLEL RUNWAYS. THE AIRCRAFT IS EQUIPPED WITH 'LIGHTWEIGHT' CLAMSHELL THRUST REVERSERS. THE RIGHT HAND THRUST REVERSER ON THE NUMBER 2 ENGINE WAS FOUND FAILED IN THE OPEN (FORWARD THRUST) POSITION. THRUST REVERSER LIGHTS DID NOT INDICATE ANY ABNORMALITIES. AN OVERSTRESS FRACTURE OF THE LOWER INNER HINGE WITH A FATIGUE FRACTURE THROUGH THE FLANGE OF THE UPPER OUTER HINGE WAS FOUND BY METALLURGICAL EXAMINATION.

## Aircraft

- Registration: [N308AS](https://openairdocs.org/deregistered/N308AS-2018-02-13), registration cancelled 2018-02-13, S/N 22002, built 1980 (OpenAirDocs)
- Reported make and model: BOEING 727-200
- Registry model: [Boeing 727-227](https://openairdocs.org/model/boeing-727-227) (registry code 1384078) (OpenAirDocs)
- Registry engine: [Pratt & Whitney JT8D-17 series](https://openairdocs.org/engine/pratt-whitney-jt8d-17-series) (registry code 52049, turbo-jet) (OpenAirDocs)
- Category: Airplane
- Serial number: 227
- Engines: P&W JT8D-17R 16400 horsepower turbo fan
- Damage: Minor damage
- Flight: Part 121
- Operator: Alaska Airlines, Inc.
- Registered owner: United States Trust Co. Of Ny
- Airworthiness certificate: Standard, Transport
- Last inspection: 100 hour, May 31, 1988, 98 hours before
- Departed: PDX, PORTLAND, OR
- Destination: SEA, SEATTLE, WA
- Flight plan: IFR
- Airport: SEA, Seattle-Tacoma Int'L., runway 34R, 11,900 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 40; flight engineer, commercial, airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 9,240 total, 7,803 in this make and model, 123 in the last 90 days, 53 in the last 30 days

## Weather

- Conditions: Visual (VMC), Night/dark
- Wind: 30° at 11 knots
- Visibility: 20 statute miles
- Lowest ceiling: none
- Temperature: 59 °F, dew point 48 °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 19880612029879I](https://openairdocs.org/incident/19880612029879I), Jun 12, 1988: Boeing 727227, Seattle, WA. Lost directional control of aircraft on rollout. Veered off runway. Found a broken thrust reverser clamshell door.

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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