# NTSB LAX93LA356: Cessna 182A, N6336B, Oracle, AZ, September 17, 1993

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Limited investigation · Final report
- Date: September 17, 1993, 10:05 local (17:05 UTC)
- Place: Oracle, AZ
- Coordinates: 32.08974, -111.079017 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=32.0897&lon=-111.0790&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious, 2 uninjured
- Status: Completed, report June 24, 1994
- Report: Approved by Office Director
- NTSB case key (mKey): 28478
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX93LA356
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/28478/pdf
- Page: https://openairdocs.org/ntsb/LAX93LA356

## Probable cause

FAILURE OF THE CRANKSHAFT DUE TO FATIGUE.

## 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
  - engine assembly,crankshaft - fatigue (cause)
- Forced landing, descent - emergency
- In flight collision with object, landing
  - object - tree(s) (contributing factor)

## Analysis

DURING A LOCAL VFR FLIGHT, THE ENGINE LOST POWER.  THE PILOT TRIED TO LAND ON AN ASPHALT SURFACED ROAD, BUT WAS UNABLE TO REACH THE ROADWAY.  DURING THE FORCED LANDING, THE AIRPLANE COLLIDED WITH TREES ON UNEVEN DESERT TERRAIN AND WAS DAMAGED.  AN EXAMINATION OF THE ENGINE REVEALED THAT THE CRANKSHAFT HAD FAILED FORWARD OF THE NUMBER ONE JOURNAL.  THE FRACTURED SURFACES DISPLAYED BEACH MARKS CONSISTENT WITH FATIGUE.  THERE WAS NO EVIDENCE THAT THE ENGINE HAD SUSTAINED ANY HIGH TEMPERATURE DISTRESS OR LACK OF LUBRICATION.  THE ENGINE HAD ACCRUED ABOUT 4434 HOURS SINCE NEW AND ABOUT 1110 HOURS SINCE IT WAS OVERHAULED ON 12/10/87.

## Factual narrative

On September 17, 1993, at 1005 hours mountain standard time, a Cessna 182A, N6336B, collided with some trees during an emergency landing near Oracle Junction, Arizona.  The emergency landing was precipitated by a total loss of engine power during cruise flight.  The pilot was conducting a local visual flight rules personal flight.  The airplane, operated by D. Genzman, dba Snoopy's Flight School, Tucson, Arizona, sustained substantial damage.  The certificated private pilot and one passenger were not injured; one passenger sustained serious injuries and was subsequently hospitalized.  Visual meteorological conditions prevailed.  The flight originated at Ryan Field, Tucson, Arizona, at 0935.

Mr. Dean Hennies, Aviation Safety Inspector [Airworthiness], Scottsdale [Arizona] Flight Standards District Office, examined the engine on October 6, 1993.  The examination revealed that the crankshaft broke forward on the number one (1) connecting rod journal.  The fractured surfaces displayed beach marks consistent with fatigue.  There was no evidence that the engine sustained any high temperature distress.  The engine displayed normal lubrication signatures.

The maintenance records examination revealed that the engine had accrued about 4,434 hours since new and about 1,110 hours since major overhaul.  The major overhaul was accomplished on December 10, 1987.

## Aircraft

- Registration: [N6336B](https://openairdocs.org/aircraft/N6336B), registered now, S/N 34236, built 1957 (OpenAirDocs)
- Reported make and model: CESSNA 182A
- Registry model: [Cessna 182A](https://openairdocs.org/model/cessna-182a) (registry code 2072704) (OpenAirDocs)
- Category: Airplane
- Serial number: 34236
- Airframe hours: 4433
- Engines: CONTINENTAL O-470 230 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Dennis W. Genzman
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, August 16, 1993, 8 hours before
- Departed: RYN, RYAN FIELD, AZ
- Destination: RYN

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 45; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 133 total, 22 in this make and model, 78 as pilot in command, 8 in the last 90 days, 3 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 130° at 12 knots
- Visibility: 40 statute miles
- Lowest ceiling: none
- Temperature: 90 °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).

- [Accident 19930917034939A](https://openairdocs.org/incident/19930917034939A), Sep 17, 1993: Cessna 182A, Oracle Junction, AZ, Substantial damage. Collided with trees during forced landing after power loss. Crankshaft had broken due to fatigue.

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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