# NTSB LAX97LA116: Beech J35, N39W, Morristown, AZ, March 3, 1997

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Limited investigation · Final report
- Date: March 2, 1997, 17:50 local (Mar 3, 1997, 00:50 UTC)
- Place: Morristown, AZ
- Coordinates: 33.979335, -112.440864 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=33.9793&lon=-112.4409&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious, 1 minor
- Status: Completed, report January 7, 1998
- Report: Approved by Office Director
- NTSB case key (mKey): 29736
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX97LA116
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/29736/pdf
- Page: https://openairdocs.org/ntsb/LAX97LA116

## Probable cause

failure of the crankshaft due to improper inspection/overhaul procedures.

## 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 - normal
- Forced landing, cruise - normal
- Nose over, emergency landing

## Analysis

While in cruise flight the pilot felt a slight vibration and immediately made a power change without affect.  After reducing the engine rpm from 2300 to 2100, the airplane vibrated hard for a split second and then smoothed out.  At that point, the propeller had separated from the engine with part of the crankshaft.  Metallurgical examination of the crankshaft revealed that the fatigue failure occurred inside the crankshaft bore 1.7 inches forward of the crankshaft oil seal.  The point of origin was at two corrosion pits.

## Factual narrative

On March 2, 1997, about 1750 hours mountain standard time, a Beech J35, N39W, was substantially damaged during a forced landing at Morristown, Arizona.  The pilot received minor injuries and the passenger received serious injuries.  Visual meteorological conditions prevailed for the personal cross-country flight and no flight plan was filed.

The pilot reported that while in cruise flight he felt a vibration and immediately made a power change without affect.  He further reduced the engine rpm from 2,300 to 2,100, the airplane vibrated hard for a split second and then smoothed out.  At that point, the propeller separated from the engine with part of the crankshaft.  The failure occurred over remote desert terrain and the propeller was not recovered.

ENGINE INFORMATION

According to the engine logbook, the engine had been overhauled on April 11, 1989, at 1,819 total hours.  At the time of the accident, the engine had accumulated about 937 hours since the overhaul.

Postaccident metallurgical examination of the crankshaft revealed that it had failed approximately 1.7 inches forward of the crankshaft oil seal.  From this fatigue cracking origin, it propagated at a 45-degree angle to the axis of the crankshaft forward and aft.  The origin was located inside the crankshaft bore at two corrosion pits.

## Aircraft

- Registration: [N39W](https://openairdocs.org/deregistered/N39W-1999-07-15), registration cancelled 1999-07-15, S/N D-5353 (OpenAirDocs)
- Reported make and model: Beech J35
- Registry model: [Beech J35](https://openairdocs.org/model/beech-j35) (registry code 1151522) (OpenAirDocs)
- Category: Airplane
- Serial number: D-5353
- Airframe hours: 4435
- Engines: Continental IO-470-C 260 horsepower reciprocating
- Damage: Destroyed
- Flight: Personal, Part 91
- Registered owner: Rafael L. Valenzuela
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, October 26, 1996, 50 hours before
- Departed: IFP, BULLHEAD CITY, AZ
- Destination: DVT, DEER VALLEY, AZ
- Airport: NONE, Private

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 62; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 392 total

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 50 statute miles
- Lowest ceiling: none
- Temperature: 64 °F

## 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 19970303002009A](https://openairdocs.org/incident/19970303002009A), Mar 3, 1997: Beech J35, Morristown, AZ, Substantial damage. Pilot reported propeller separated from engine, struck right wing, made emergency landing inverted.

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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