# NTSB LAX91LA068: Cessna 172N, N737FJ, Ukiah, CA, January 6, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: January 6, 1991, 10:30 local (18:30 UTC)
- Place: Ukiah, CA
- Coordinates: 39.120784, -123.280395 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=39.1208&lon=-123.2804&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 4 uninjured
- Status: Completed, report December 4, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 27088
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX91LA068
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27088/pdf
- Page: https://openairdocs.org/ntsb/LAX91LA068

## Probable cause

THE FAILURE OF THE PILOT TO MAINTAIN AN ADEQUATE CLEARANCE FROM GROUND OBSTRUCTIONS.   A FACTOR IN THE ACCIDENT WAS: FAILURE OF THE PILOT TO MAINTAIN AN ALTITUDE SUFFICIENT TO CLEAR ALL OBSTRUCTIONS ALONG HIS ROUTE OF FLIGHT.

## Sequence of events

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

- In flight collision with object, cruise
  - proper altitude - not maintained, pilot in command (contributing factor)
  - object - wire,transmission
  - clearance - not maintained, pilot in command (cause)

## Analysis

THE PILOT SAID HE WAS FLYING DOWN A RIVER VALLEY AT ABOUT 800 FT AGL AS HE AND HIS PASSENGERS WERE LOOKING OVER POTENTIAL TIMBER CUTTING AREAS.  THE FLIGHT CROSSED A SADDLE IN THE MOUNTAINS WHICH REDUCED THE GROUND CLEARANCE TO ABOUT 300 FT.  SUDDENLY, HE SAW AN UNMARKED HIGH TENSION POWER LINE DIRECTLY AHEAD.  HE INITIATED A DIVING LEFT TURN IN AN ATTEMPT TO AVOID THE WIRE; HOWEVER, THE OUTBOARD RIGHT WING STRUCK THE WIRE.  THE PILOT SAID THE OUTBOARD RIGHT WING SUSTAINED A SIGNIFICANT AMOUNT OF DAMAGE AND CONTROL OF THE AIRCRAFT WAS DIFFICULT IN THE ROLL AXIS.  THE PILOT FLEW THE AIRCRAFT TO UKAIH, WHERE A SUCCESSFUL LANDING WAS MADE.  ACCORDING TO THE PILOT, THE POWER LINE CROSSED PERPENDICULAR TO THE VALLEY WITH THE LINE SUSPENDED FROM TOWERS ON TOP OF RIDGES ON OPPOSITE SIDES OF THE VALLEY.

## Aircraft

- Registration: [N737FJ](https://openairdocs.org/aircraft/N737FJ), registered now, S/N 17269382, built 1977 (OpenAirDocs)
- Reported make and model: CESSNA 172N
- Registry model: [Cessna 172N](https://openairdocs.org/model/cessna-172n) (registry code 2072434) (OpenAirDocs)
- Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 17269382
- Engines: LYCOMING O-320-HZAD 150 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Arthur C. Hunter
- Departed: 028, WILLITS, CA

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 44; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, valid medical--no waivers/lim.; flight hours: 863 total, 808 in this make and model, 817 as pilot in command, 29 in the last 90 days, 2 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 30 statute miles
- Lowest ceiling: none
- Temperature: -0 °F, dew point -0 °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 19910106000239A](https://openairdocs.org/incident/19910106000239A), Jan 6, 1991: Cessna 172N, Ukiah, CA, Substantial damage. While surveying timber struck a powerline that was stretched over river valley. Was able to return to base.

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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