# NTSB ANC91IA028: Boeing 737-200, N672MA, Unalaska, AK, February 13, 1991

- Type: NTSB incident investigation
- Classification: Incident · No injuries · Incident investigation · Final report
- Date: February 13, 1991, 12:39 local (16:39 UTC)
- Place: Unalaska, AK
- Coordinates: 53.890789, -166.540237 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=53.8908&lon=-166.5402&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 46 uninjured
- Status: Completed, report March 9, 1993
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- NTSB case key (mKey): 5494
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC91IA028
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/5494/pdf
- Page: https://openairdocs.org/ntsb/ANC91IA028

## Probable cause

THE WINDSHEAR ENCOUNTERED ON SHORT FINAL.  CONTRIBUTING TO THE ACCIDENT WAS THE RISING TERRAIN WITHIN 150 FEET OF THE RUNWAY, THE VARIABLE NATURE OF THE WIND DUE TO THE RISING TERRAIN, AND THE PILOT'S FAILURE TO MAINTAIN LATERAL CONTROL DURING THE GO AROUND.

## Sequence of events

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

- Dragged wing,rotor,pod,float or tail/skid, go-around (vfr)
  - weather condition - windshear (cause)
  - terrain condition - mountainous/hilly (contributing factor)
  - weather condition - unfavorable wind (contributing factor)
  - aircraft control - not maintained, pilot in command (contributing factor)

## Analysis

THE RUNWAY ALIGNS FROM THE SOUTHEAST TO THE NORTHWEST AND WITHIN 150 FEET EAST OF THE RUNWAY IS A 1,634 FOOT HIGH MOUNTAIN.  THE WIND WAS FROM THE NORTHWEST AT 14 KNOTS, GUSTING TO 25 KNOTS.  THE LANDING THRESHOLD FOR RUNWAY 30 WAS DIRECTLY DOWNWIND OF THE MOUNTAIN.  DURING THE FINAL APPROACH, THE FIRST OFFICER NOTICED A PLUS 30 KNOT DEVIATION IN THE AIRSPEED AND CALLED FOR THE CAPTAIN TO INITIATE A GO AROUND.  THE CAPTAIN HAD ALREADY APPLIED POWER WHEN THE AIRPLANE BEGAN TO SINK AND ROLL TO THE RIGHT.  THE RIGHT WING TIP SCRAPED THE RUNWAY SURFACE DURING THE GO AROUND.

## Aircraft

- Registration: N672MA (not matched to a registry record)
- Reported make and model: BOEING 737-200
- Category: Airplane
- Engines: P&W JT8D turbo jet
- Damage: Minor damage
- Flight: Part 121
- Operator: Markair, Inc.
- Registered owner: Markair, Inc.
- Airworthiness certificate: Standard, Transport
- Last inspection: Unknown, January 2, 2000
- Departed: ANC, ANCHORAGE, AK
- Destination: DUT, UNALASKA, AK
- Flight plan: IFR
- Airport: DUT, Unalaska, runway 3, 3,800 × 100 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 46; airline transport, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left

## Weather

- Conditions: Visual (VMC), Day
- Wind: 350° at 15 knots, gusting 26
- Visibility: 6 statute miles
- Lowest ceiling: 2,700 ft broken
- Temperature: 28 °F, dew point 25 °F
- Altimeter: 29.00 inHg
- Observed at: DUT, 1 nm away

## 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 19910213008899I](https://openairdocs.org/incident/19910213008899I), Feb 13, 1991: Boeing 7372X6C, Unalaska, AK, Minor damage. Encountered wind shear on final. Aircraft rolled and wing tip hit runway. Made go around and landed safely.

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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