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NYC91LA092 · Piper PA-23-160

23 Mar 1991 · Westbrook, ME, United States

Phoenix East Aviation Piper PA-23-160 · Accident: total loss of engine power (mechanical failure) en route

From Millinocket Municipal Airport (MLT) to Lawrence Municipal Airport (LWM)

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Event

NTSB case
NYC91LA092
Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
Accident
InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
Completed
API-reported fatalities
0 · all aircraft and ground
Ground fatalities
0
OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
General aviation
WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
Instrument Meteorological Cond

Piper PA-23-160

Aircraft type
Piper PA-23
Category
Airplane
RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
N4155P
Onboard fatalities
Unknown
Route
From Millinocket Municipal Airport (MLT), Millinocket, METo Lawrence Municipal Airport (LWM), Lawrence, MA
Aircraft age
Not recorded
Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
Part 91: General Aviation
Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
En route · cruise
First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
Total loss of engine power (mechanical failure)
DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
Substantial

Cause areas

  • 1 engine
  • Pilot in command(cfi) › Emergency procedure, improper
  • Pilot in command(cfi) › Inadequate training(emergency procedure(s))
  • Pilot in command(cfi) › Lack of total experience in type of aircraft
  • Pilot in command(cfi) › Operation with known deficiencies in equipment, intentional
  • Pilot in command(cfi) › Preflight planning/preparation, improper

Approximate · Estimated position: the centre of Westbrook, ME, the place the record names. Not the accident site.

NTSB narrative

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.

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.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record NYC91LA092
Event ID
20001212X16688
Case number
NYC91LA092
Dataset
historical-pre2008
Source SHA-256
89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
  • Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
  • Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
  • The date is the local date, which is the same as the UTC date the NTSB stores.
  • API snapshot SHA-256: fc1d9dc4216c41d564ff772e13429bce56b81148f689d5281d8260d2a8ee7618; retrieved 2026-09-23T04:33:03.949Z.