# NTSB SEA92LA007: Piper PA24-180, N7759P, Marysville, WA, October 14, 1991

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: October 14, 1991, 15:30 local (22:30 UTC)
- Place: Marysville, WA
- Coordinates: 48.050468, -122.139762 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=48.0505&lon=-122.1398&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 3 minor
- Status: Completed, report April 27, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 41601
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA92LA007
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41601/pdf
- Page: https://openairdocs.org/ntsb/SEA92LA007

## Probable cause

THE SLIPPAGE OF THE ACCESSARY DRIVE GEAR DUE TO IMPROPER MAINTENANCE BY OTHER MAINTENANCE PERSONNEL. FACTORS INCLUDE A FORCED LANDING IN UNSUITABLE TERRAIN.

## 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, climb - to cruise
  - accessory drive assy,drive gear - slipped (cause)
  - maintenance,service bulletin/letter - not followed, other maintenance personnel
- Forced landing, descent - emergency
- In flight collision with terrain/water, landing
  - terrain condition - none suitable (contributing factor)

## Analysis

A PIPER PA 24 IMPACTED THE TERRAIN DURING A FORCED LANDING, AFTER A TOTAL ENGINE FAILURE ON CLIMBOUT.  INVESTIGATION REVEALED THAT THE ACCESSARY DRIVE GEAR WAS LOOSE ON THE END OF THE CRANKSHAFT, AND WAS THEREFORE NOT DRIVING THE ACCESSARY SECTION.  THE AIRCRAFT HAD EXPERIENCED A PROPELLER STRIKE AT AN EARLIER DATE, AND THE INSTRUCTIONS IN THE TEXTRON LYCOMING SERVICE BULLETIN WERE NOT FOLLOWED WHEN THE REPAIRS WERE PERFORMED.  THE BULLETIN CALLED FOR A NEW STYLE DRIVE GEAR AND GEAR RETAINING BOLT, BUT THE OLD STYLE PARTS WERE INSTALLED INSTEAD.  ACCORDING TO LYCOMING, THE NEW PARTS MUST BE USED IN ORDER TO INSURE THAT THE GEAR SEATS ON THE CRANKSHAFT MOUNTING FACE, AND DOES NOT WORK LOOSE DURING ENGINE OPERATION.

## Aircraft

- Registration: [N7759P](https://openairdocs.org/deregistered/N7759P-1994-08-25), registration cancelled 1994-08-25, S/N 242975 (OpenAirDocs)
- Reported make and model: PIPER PA24-180
- Registry model: [Piper PA-24](https://openairdocs.org/model/piper-pa-24) (registry code 7102402) (OpenAirDocs)
- Category: Airplane
- Serial number: 2975
- Airframe hours: 2673
- Engines: LYCOMING O360A1D 180 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Jenkins Aircraft
- Registered owner: Jenkins Aircraft
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, August 15, 1991, 33 hours before
- Departed: S88, ARLINGTON, WA
- Destination: OS9, PORT TOWNSEND, WA

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 69; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 1,288 total, 1,200 as pilot in command, 40 in the last 90 days, 7 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 50 statute miles
- Lowest ceiling: none

## 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 19911014046139A](https://openairdocs.org/incident/19911014046139A), Oct 14, 1991: Piper PA24, Maryville, WA, Substantial damage. Engine lost power on climb to cruise. Landed in trees. Crankshaft accessory drive gear dowel sheared.

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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