# NTSB ANC92IA001: Piper PA-31-350, N200AK, Fairbanks, AK, October 2, 1991

- Type: NTSB incident investigation
- Classification: Incident · No injuries · Incident investigation · Final report
- Date: October 2, 1991, 13:20 local (21:20 UTC)
- Place: Fairbanks, AK
- Coordinates: 64.810462, -147.719955 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=64.8105&lon=-147.7200&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 5 uninjured
- Status: Completed, report May 5, 1993
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- NTSB case key (mKey): 5655
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC92IA001
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/5655/pdf
- Page: https://openairdocs.org/ntsb/ANC92IA001

## Probable cause

INCORRECT INSTALLATION OF CRANKSHAFT COUNTERWWEIGHT ROLLERS BY THE MANUFACTURER DURING REMANUFACTURE OF THE ENGINE. FACTOR WAS THE INADEQUATE SURVEILLANCE OF THE ENGINE ASSEMBLY PROCESS BY THE MANUFACTURER.

## 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
  - eng assembly,crankshaft counterweights/vib damper - improper (cause)
  - maintenance,rebuild/remanufacture - improper, manufacturer (cause)
  - inadequate surveillance of operation, manufacturer (contributing factor)

## Analysis

DURING CRUISE FLIGHT, THE LEFT ENGINE LOST POWER AND OIL PRESSURE. AN ENGINE TEARDOWN ANALYSIS SHOWED THAT THE CRANKSHAFT COUNTERWEIGHTS HAD TWO INCORRECT OF THE FOUR INSTALLED ROLLERS.  ALL FOUR ROLLERS WERE PART NO. 73648. ACCORDING TO TEXTRON LYCOMING, THE CORRECT ROLLER CONFIGURATION SHOULD HAVE BEEN 'TWO PART NO. 73648 5.1 ORDER AND TWO PART NO. 76788 6.3 ORDER ROLLERS.'  AS CONFIGURED, THE ENGINE WOULD EXPERIENCE UNACCEPTABLE 6TH ORDER TORSIONAL VIBRATIONS.

## Aircraft

- Registration: [N200AK](https://openairdocs.org/deregistered/N200AK-2023-01-10), registration cancelled 2023-01-10, S/N 31-8052180, built 1980 (OpenAirDocs)
- Reported make and model: PIPER PA-31-350
- Registry model: [Piper PA-31-350](https://openairdocs.org/model/piper-pa-31-350) (registry code 7103110) (OpenAirDocs)
- Registry engine: [Lycoming TI0-540 series](https://openairdocs.org/engine/lycoming-ti0-540-series) (registry code 41533, turbo-prop) (OpenAirDocs)
- Category: Airplane
- Serial number: 31-8052180
- Airframe hours: 1763
- Engines: LYCOMING TIO-540J2BD 350 horsepower reciprocating
- Damage: Minor damage
- Fire: In-Flight
- Flight: Part 135
- Operator: Frontier Flying Service Inc.
- Registered owner: Frontier Flying Service Inc.
- Airworthiness certificate: Standard, Utility; Standard, Normal
- Last inspection: AAIP, September 27, 1991, 26 hours before
- Departed: FAI, FAIRBANKS, AK
- Destination: CXF, COLDFOOT, AK
- Flight plan: VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 35; private, airline transport; airplane ratings: single-engine land, multi-engine land, single-engine sea; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 8,000 total, 6,000 in this make and model, 7,800 as pilot in command, 300 in the last 90 days, 100 in the last 30 days, 6 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 99 statute miles
- Lowest ceiling: none
- Temperature: 39 °F
- Altimeter: 30.00 inHg

## 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 19911002055499I](https://openairdocs.org/incident/19911002055499I), Oct 2, 1991: Piper PA31350, Fairbanks, AK, Minor damage. Left engine losing power after departure. Smoke and flames. Secured and flames quit. Evacuated on taxiway.

## Other investigations on N200AK (1)

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.

- [NTSB ANC07LA048](https://openairdocs.org/ntsb/ANC07LA048), Jun 13, 2007: Piper PA-31-350 (N200AK), Tuluksak, AK, substantial damage. Probable cause: The loss of engine power during cruise due to the pilot's failure to refuel the airplane prior to fuel exhaustion. Factors contributing to the accident were the delayed extension of the gear, and the…

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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