# NTSB NYC91LA092: Piper PA-23-160, N4155P, Westbrook, ME, March 23, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: March 23, 1991, 16:08 local (21:08 UTC)
- Place: Westbrook, ME
- Location: 43.7079° N, 70.3526° W: Placed by OpenAirDocs: center of Westbrook, ME, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=43.7079&lon=-70.3526&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 4 uninjured
- Status: Completed, report May 5, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 36893
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC91LA092
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/36893/pdf
- Page: https://openairdocs.org/ntsb/NYC91LA092

## Probable cause

IMPROPER EMERGENCY PROCEDURES BY THE PILOT.  FACTORS RELATED TO THE ACCIDENT WERE: THE PILOT'S LACK OF EXPERIENCE AND FLIGHT TIME IN TYPE OF AIRPLANE, THE PILOTS DECISION TO TAKE AN AIRPLANE WITH A KNOWN MECHANICAL DEFECT, A LEAKY ACCELERATOR PUMP SEAL ON THE CARBURETOR, AND INSTRUMENT METEOROLOGICAL CONDITIONS.

## Sequence of events

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

- Loss of engine power(total) - mech failure/malf, cruise - normal
  - preflight planning/preparation - improper, pilot in command(cfi) (cause)
  - operation with known deficiencies in equipment - intentional, pilot in command(cfi) (cause)
  - fuel system,carburetor - failure,partial (contributing factor)
  - maintenance,adjustment - improper, other maintenance personnel (contributing factor)
  - 1 engine (cause)
  - emergency procedure - improper, pilot in command(cfi) (cause)
  - inadequate training(emergency procedure(s)), pilot in command(cfi) (cause)
  - lack of total experience in type of aircraft, pilot in command(cfi) (cause)
- Forced landing, descent - emergency
  - altitude - not maintained, pilot in command(cfi)
- On ground/water encounter with terrain/water, landing - flare/touchdown
  - weather condition - clouds (contributing factor)
  - weather condition - snow (contributing factor)
  - terrain condition - rough/uneven (contributing factor)

## Analysis

ON AN IFR FLIGHT IN IMC CONDITIONS THE RIGHT ENGINE STARTED TO SHUDDER AND PRODUCE BLACK SMOKE, AND THEN THE PROPELLER WENT INTO FEATHER WITHOUT ACTUATION OF THE PROPELLER CONTROL.  THE PILOT WAS UNABLE TO MAINTAIN ALTITUDE AND THE PILOT MADE A FORCED LANDING IN AN OPEN FIELD.  THE RIGHT ENGINE OIL WAS DILUTED BY GASOLINE, DUE TO A LEAK IN THE ACCELERATOR PUMP OF THE CARBURETOR WHICH CAUSED THE ENGINE TO RUN RICH.  INTERVIEWS DISCLOSED THE PILOT HAD 'DENIAL' ON THE ENGINE PROBLEM, DID NOT SECURE THE ENGINE, AND DID NOT DECLARE AN EMERGENCY WITH ARC.  BOTH ENGINES WERE HIGH TIME WITH HIGH TIME SINCE OVERHAUL.  HARTZELL PROPELLERS PERSONNEL VERIFIED DILUTED OIL COULD CAUSE A PROPELLER TO GO INTO UNCOMMANDED FEATHER.

## Aircraft

- Registration: [N4155P](https://openairdocs.org/deregistered/N4155P-2003-01-28), registration cancelled 2003-01-28, S/N 23-1639, built 1959 (OpenAirDocs)
- Reported make and model: PIPER PA-23-160
- Registry model: [Piper PA-23-160](https://openairdocs.org/model/piper-pa-23-160) (registry code 7102304) (OpenAirDocs)
- Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 23-1639
- Airframe hours: 5297
- Engines: LYCOMING O-320B 160 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Phoenix East Aviation
- Registered owner: Phoenix East Aviation
- Last inspection: 100 hour, October 28, 1990, 131 hours before
- Departed: MLT, MILLINOCKET, ME
- Destination: LWM, LAWRENCE, MA
- Flight plan: IFR
- Airport: PWM, Portland

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 23; flight instructor, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: right; flight hours: 975 total, 31 in this make and model, 904 as pilot in command, 139 in the last 90 days, 66 in the last 30 days, 4 in the last 24 hours

## Weather

- Conditions: Instrument (IMC), Day
- Wind: 130° at 14 knots, gusting 23
- Lowest ceiling: 500 ft
- Observed at: PWM, 6 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 19910323007299A](https://openairdocs.org/incident/19910323007299A), Mar 23, 1991: Piper PA23160, Portland, ME, Substantial damage. Lost power right engine. Unable fly due failure to feather. Carb set too rich. Did not lean. Engine poor condition.

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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