# NTSB LAX92LA110: Grumman G-164A, N8507H, Greenfield, CA, February 5, 1992

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: February 4, 1992, 16:10 local (Feb 5, 1992, 00:10 UTC)
- Place: Greenfield, CA
- Coordinates: 36.259521, -121.370223 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=36.2595&lon=-121.3702&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report August 31, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 27552
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX92LA110
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27552/pdf
- Page: https://openairdocs.org/ntsb/LAX92LA110

## Probable cause

THE PILOT'S FAILURE TO MAINTAIN ADEQUATE ALTITUDE DURING AN INTENTIONALLY PERFORMED LOW ALTITUDE FLIGHT IN MOUNTAINOUS TERRAIN.  CONTRIBUTING FACTORS RELATED TO THE PILOT'S VISUAL PERCEPTION OF THE CANYON AREA BECAUSE OF CHANGES IN THE AMBIENT LIGHTING CONDITIONS AND SHADOWS.

## Sequence of events

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

- In flight collision with terrain/water, maneuvering
  - terrain condition - mountainous/hilly
  - terrain condition - blind/box canyon
  - altitude - inadequate, pilot in command (cause)
  - light condition - dusk (contributing factor)
  - visual/aural perception, pilot in command (contributing factor)

## Analysis

THE PILOT, WHO HAD LOGGED 20,000 FLIGHT HOURS, WAS WORKING FOR A FILM CREW TO LOCATE PICTURESQUE AREAS FOR FILMING. DURING THE ACCIDENT FLIGHT THE PILOT, WHO WAS FAMILIAR WITH THE AREA, FLEW AT AN INTENTIONALLY LOW ALTITUDE IN MOUNTAINOUS TERRAIN.  ACCORDING TO THE PILOT, WHILE CRUISING HE EXPERIENCED CHANGES IN THE AMBIENT LIGHTING CONDITIONS AND HILLSIDE SHADOWS, AND HE FAILED TO NEGOTIATE A CRITICAL TURN.  HE INADVERTENTLY TURNED INTO A BOX-LIKE CANYON, FOR WHICH 'THERE WAS NO ESCAPE,'  AND COLLIDED WITH UPSLOPING TERRAIN.

## Aircraft

- Registration: [N8507H](https://openairdocs.org/deregistered/N8507H-2012-08-14), registration cancelled 2012-08-14, S/N 1384, built 1974 (OpenAirDocs)
- Reported make and model: GRUMMAN G-164A
- Registry model: [Grumman Acft ENG Cor-Schweizer G-164A](https://openairdocs.org/model/grumman-acft-eng-cor-schweizer-g-164a) (registry code 3952801) (OpenAirDocs)
- Registry engine: [Pratt & Whitney R1340 series](https://openairdocs.org/engine/pratt-whitney-r1340-series) (registry code 52016, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 1384
- Airframe hours: 1886
- Engines: P&W R-1340-AN1 600 horsepower reciprocating
- Damage: Destroyed
- Flight: Other work use, Part 91
- Operator: Brad Christian Films
- Registered owner: Vince Crop Dusters
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: 100 hour, October 4, 1991, 48 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 52; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: center; flight hours: 20,000 total, 650 in this make and model, 19,000 as pilot in command, 60 in the last 90 days, 20 in the last 30 days, 5 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 50 statute miles
- Lowest ceiling: none
- Temperature: 70 °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 19920204053029A](https://openairdocs.org/incident/19920204053029A), Feb 4, 1992: Scwzer G164A, Greenfield, CA, Destroyed. Flew into box canyon by mistake at low altitude. Struck canyon wall turning back. Was scouting filming areas.

## Other investigations on N8507H (4)

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.

- [NTSB LAX95LA186](https://openairdocs.org/ntsb/LAX95LA186), May 11, 1995: Grumman 164A (N8507H), Richvale, CA, substantial damage. Probable cause: the pilot's failure to maintain a glidepath adequate to avoid an obstacle, and his inadequate compensation for the wind.
- [NTSB LAX94LA247](https://openairdocs.org/ntsb/LAX94LA247), Jun 11, 1994: Grumman G-164A (N8507H), Bakersfield, CA, substantial damage. Probable cause: THE IN-FLIGHT FIRE DUE TO THE SPONTANEOUS COMBUSTION OF SULFUR DUST AND SUBSEQUENT FORCED LANDING. A FACTOR WAS THE HIGH TEMPERATURE.
- [NTSB LAX81DVA08](https://openairdocs.org/ntsb/LAX81DVA08), Oct 22, 1980: Grumman G-164A (N8507H), Bakersfield, CA, substantial damage
- [NTSB LAX76DVA05](https://openairdocs.org/ntsb/LAX76DVA05), Oct 4, 1976: Grumman G-164A (N8507H), Old River, CA, substantial damage

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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