# NTSB FTW90LA102: Piper PA-32-260, N7732J, Tulsa, OK, April 27, 1990

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: April 27, 1990, 09:27 local (14:27 UTC)
- Place: Tulsa, OK
- Coordinates: 36.189033, -95.909706 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=36.1890&lon=-95.9097&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor
- Status: Completed, report January 23, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 23126
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW90LA102
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/23126/pdf
- Page: https://openairdocs.org/ntsb/FTW90LA102

## Probable cause

AN ENGINE FAILURE DUE TO A DISCONNECT IN THE MAGNETO DRIVE TRAIN CAUSED BY THE CRANKSHAFT GEAR NOT BEING PROPERLY INSTALLED AND SECURED DURING A RECENT ENGINE OVERHAUL.

## 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, approach - faf/outer marker to threshold (ifr)
  - ignition system,magneto - disconnected (cause)
  - accessory drive assy,drive gear - not secured (cause)
  - maintenance,overhaul - improper, other maintenance personnel (cause)
- Forced landing, approach - faf/outer marker to threshold (ifr)
- In flight collision with object, approach - faf/outer marker to threshold (ifr)
  - terrain condition - none suitable (contributing factor)
  - object - tree(s)

## Analysis

WHILE ON FINAL, THE ENGINE QUIT WITHOUT WARNING AND THE PILOT WAS FORCED TO EXECUTE A FORCED LANDING INTO A HEAVILY WOODED BIRD SANCTUARY. EXAMINATION OF THE ENGINE REVEALED THAT THE CRANKSHAFT GEAR ATTACHMENT BOLT WAS LOOSE WITH 0.196 INCHES OF PLAY AND THE DOWEL PIN WAS SHEARED. GEAR INSTALLATION INSTRUCTIONS CALLED FOR THE GEAR TO BE SEATED WITH A DRIFT AND HAMMER WITH NO MORE THAN 0.001 INCHES OF CLEARANCE. OTHERWISE, THE DOWEL PIN WOULD BE OFFSET AND WORK. BOTH THE BOLT AND THE DOWEL PIN SHOWED EVIDENCE OF WORKING. SHEARING OF THE CRANKSHAFT DOWEL PIN WOULD HAVE RELEASED THE GEAR TO ROTATE ABOUT THE BOLT, THUS DISCONNECTING THE GEAR AND THE IDLER GEARS WHICH TRANSMITTED TORQUE TO THE MAGNETOS. SECONDARY DAMAGE WAS OBSERVED IN THE LEFT MAGNETO. MAINTENANCE RECORDS INDICATED THAT THE ENGINE HAD BEEN OVERHAULED 88.7 HOURS PRIOR TO THE ACCIDENT.

## Aircraft

- Registration: [N7732J](https://openairdocs.org/deregistered/N7732J-1992-05-12), registration cancelled 1992-05-12, S/N 321135 (OpenAirDocs)
- Reported make and model: PIPER PA-32-260
- Registry model: [Piper PA-32-260](https://openairdocs.org/model/piper-pa-32-260) (registry code 7103206) (OpenAirDocs)
- Category: Airplane
- Serial number: 32-1135
- Airframe hours: 6106
- Engines: LYCOMING O-540-E4B5 260 horsepower reciprocating
- Damage: Destroyed
- Flight: Part 135
- Operator: Martinaire
- Registered owner: Galhoun, John L
- Airworthiness certificate: Standard, Utility; Standard, Normal
- Last inspection: AAIP, April 23, 1990, 18 hours before
- Departed: DAL, DALLAS, TX
- Flight plan: IFR
- Airport: TWL, Tulsa Int., runway 17R, 6,101 × 150 ft, concrete

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 68; flight instructor, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, invalid medical for flight; seat: left; flight hours: 18,000 total, 3,000 in this make and model, 6,000 as pilot in command, 210 in the last 90 days, 70 in the last 30 days, 4 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 8 knots
- Visibility: 10 statute miles
- Lowest ceiling: 2,000 ft broken
- Temperature: 64 °F, dew point 59 °F
- Altimeter: 29.00 inHg
- Observed at: TUL

## 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 19900427016659A](https://openairdocs.org/incident/19900427016659A), Apr 27, 1990: Piper PA32260, Tulsa, OK, Destroyed. Lost power on approach. Struck trees. Crankshaft to gear dowel pin sheared from side wear. Mag axle pins worn.

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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