# NTSB LAX89LA298: Stinson 108, N97628, Cool, CA, September 1, 1989

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: September 1, 1989, 10:38 local (17:38 UTC)
- Place: Cool, CA
- Coordinates: 38.879268, -120.980987 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=38.8793&lon=-120.9810&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report June 16, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 26492
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX89LA298
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/26492/pdf
- Page: https://openairdocs.org/ntsb/LAX89LA298

## Probable cause

FAILURE OF THE #2 PISTON.  FAILURE OF THE MECHANIC TO PROPERLY OVERHAUL THE ENGINE WAS A RELATED FACTOR.

## Sequence of events

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

- Loss of engine power(partial) - mech failure/malf, climb - to cruise
  - maintenance,overhaul,major - improper, other maintenance personnel (cause)
  - engine assembly,piston - failure,total (cause)
- Forced landing, descent - emergency
- On ground/water collision with object, landing - roll
  - object - sign
  - object - fence

## Analysis

WHILE CLIMBING TO CRUISE ALTITUDE, THE ENGINE SUSTAINED A LOSS OF POWER. UNABLE TO MAINTAIN ALTITUDE, THE PILOT ELECTED TO LAND ON AN ACCESS ROAD. THE LANDING WAS UNEVENTFUL, BUT DURING THE LANDING ROLL-OUT, THE LEFT WHEEL PANT STRUCK A ROAD MARKER. THE AIRPLANE THEN YAWED TO THE LEFT, EXITED THE ROADWAY, AND WENT THRU A BARBED WIRE FENCE AND ONTO A DIRT FIELD. AN ENGINE EXAMINATION DISCLOSED THE #2 PISTON WAS DESTROYED. THE PISTON WAS NOT IDENTIFIED AS BEING THE CORRECT ONE FOR THE ENGINE. THE ENGINE HAD ACCRUED 145 HOURS SINCE MAJOR OVERHAUL. THE OVERHAUL WAS PERFORMED BY AN A&P MECHANIC.

## Aircraft

- Registration: [N97628](https://openairdocs.org/aircraft/N97628), registered now, S/N 108-628, built 1946 (OpenAirDocs)
- Reported make and model: STINSON 108
- Registry model: [Stinson 108](https://openairdocs.org/model/stinson-108) (registry code 9230402) (OpenAirDocs)
- Registry engine: [Franklin 6A4150 series](https://openairdocs.org/engine/franklin-6a4150-series) (registry code 27024, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 108-628
- Engines: FRANKLIN 6A4-165 165 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Cassen, Gary A.
- Registered owner: Gary A Cassen
- Airworthiness certificate: Standard, Normal
- Departed: AUN, AUBURN, CA
- Destination: Q61, GEORGETOWN, CA
- Airport: 001, Auburn

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 26; private; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 305 total, 100 in this make and model, 264 as pilot in command, 25 in the last 90 days, 15 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 360° at 10 knots
- Visibility: 50 statute miles
- Lowest ceiling: none
- Temperature: 81 °F
- Altimeter: 29.00 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).

- [Accident 19890901033619A](https://openairdocs.org/incident/19890901033619A), Sep 1, 1989: Univar 108, Auburn, CA, Substantial damage. NR2 cylinder disintegrated en route made forced landing on a road. A wheel struck a marker. Veered into a fence.

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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