# NTSB SEA91LA015: Grumman American AA-1C, N9583U, Port Townsend, WA, November 15, 1990

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: November 14, 1990, 21:15 local (Nov 15, 1990, 05:15 UTC)
- Place: Port Townsend, WA
- Coordinates: 48.029571, -122.840805 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=48.0296&lon=-122.8408&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor, 1 uninjured
- Status: Completed, report November 23, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 41362
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA91LA015
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41362/pdf
- Page: https://openairdocs.org/ntsb/SEA91LA015

## Probable cause

THE PILOT'S FAILURE TO USE CARBURETOR HEAT WHICH RESULTED IN A LOSS OF ENGINE POWER AND A FORCED LANDING.

## Sequence of events

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

- Loss of engine power(total) - nonmechanical, approach - vfr pattern - base turn
  - weather condition - carburetor icing conditions
  - carburetor heat - not used, pilot in command(cfi) (cause)
- Forced landing, descent - emergency
- In flight collision with object, descent - emergency
  - object - pole

## Analysis

THE PLT REPORTED HE EXTENDED THE PATTERN DOWNWIND FOR DEPARTING ACFT. WHEN THE AIRPLANE TURNED FROM DOWNWIND TO BASE, PWR WAS REDUCED, CARB HEAT WAS APPLIED AND FLAPS WERE EXTENDED A FEW SECONDS LATER, THE STUDENT TOLD THE INSTRUCTOR SOMETHING WAS WRONG WITH THE ENGINE. THE FLT INSTRUCTOR TOOK OVER AND APPLIED PWR WITHOUT ENG RESPONSE. THE AIRPLANE WAS UNABLE TO LAND AT THE ARPT AND AN EMERGENCY OFF FIELD LANDING WAS MADE. DURING THE DESCENT, THE AIRPLANE COLLIDED WITH A PWR POLE AND NOSED OVER. DURING THE ENGINE INSPECTION THERE WERE NO NOTED MECHANICAL AILURES OR MALFUNCTIONS REPORTED. THE TEMP AND DEWPOINT SPREAD INDICATE THAT THE AIRPLANE WAS OPERATING IN SERIOUS ICING CONDITIONS FOR CRUISE OR CLIMB POWER.

## Aircraft

- Registration: [N9583U](https://openairdocs.org/deregistered/N9583U-1994-01-05), registration cancelled 1994-01-05, S/N AA1C0022 (OpenAirDocs)
- Reported make and model: GRUMMAN AMERICAN AA-1C
- Registry model: [Grumman American Avn. AA-1C](https://openairdocs.org/model/grumman-american-avn-aa-1c) (registry code 3960100) (OpenAirDocs)
- Category: Airplane
- Serial number: AA1C0022
- Engines: LYCOMING O-235 115 horsepower reciprocating
- Damage: Destroyed
- Flight: Instructional, Part 91
- Operator: Lawrence D. Sutherland

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 54; flight engineer, military, flight instructor, airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; flight hours: 22,500 total, 200 in this make and model, 10,800 as pilot in command

## Weather

- Conditions: Visual (VMC), Night/dark
- Wind: 130° at 5 knots
- Visibility: 7 statute miles
- Lowest ceiling: 3,600 ft broken
- Temperature: 46 °F, dew point 39 °F
- Altimeter: 30.00 inHg
- Observed at: NUW, 18 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).

- [Accident 19901114050279A](https://openairdocs.org/incident/19901114050279A), Nov 14, 1990: Gulstm AA1C, Port Townsend, WA, Destroyed. Engine failed respond on long final struck power pole landed inverted. Carburetor icing conditions.

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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