# NTSB LAX97LA248: Bell 47G-2, N919SF, Buttonwillow, CA, July 21, 1997

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: July 21, 1997, 10:25 local (17:25 UTC)
- Place: Buttonwillow, CA
- Coordinates: 35.430255, -119.489517 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=35.4303&lon=-119.4895&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report December 31, 1998
- Report: Approved by Office Director
- NTSB case key (mKey): 29841
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX97LA248
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/29841/pdf
- Page: https://openairdocs.org/ntsb/LAX97LA248

## Probable cause

failure of the pilot to maintain adequate clearance from a utility pole (obstruction) during aerial application.  The obstruction was a related factor.

## Sequence of events

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

- In flight collision with object, maneuvering - aerial application
  - object - utility pole (contributing factor)
  - clearance - not maintained, pilot in command (cause)

## Analysis

The pilot reported that he was spraying a cotton field that had power lines crossing it on wooden poles. He stated that as he was 'going around a pole,' the main rotor blade(s) hit the pole. The helicopter then crashed, began burning, and was destroyed.

## Factual narrative

On July 21, 1997, at 1025 hours Pacific daylight time, a Bell 47G-2, N919SF, collided with a power pole during an aerial application flight near Buttonwillow, California.  Visual meteorological conditions prevailed at the time of the accident and no flight plan was filed.  The helicopter was destroyed in the collision sequence and postcrash fire.  The commercial pilot, the sole occupant, was not injured.  The helicopter was operating under Title 14 CFR Part 137, and the flight originated from the field to be sprayed at approximately 1000.

In his written report, the pilot stated that he was spraying a cotton field that had power lines on wooden poles going through it.  He stated that he was going around a pole and the main rotor blade hit the pole.  The helicopter then rolled over, caught on fire, and was destroyed.

## Aircraft

- Registration: [N919SF](https://openairdocs.org/deregistered/N919SF-2000-12-28), registration cancelled 2000-12-28, S/N 1695 (OpenAirDocs)
- Reported make and model: Bell 47G-2
- Registry model: [Bell 47G-2](https://openairdocs.org/model/bell-47g-2) (registry code 1181008) (OpenAirDocs)
- Category: Helicopter
- Serial number: 1695
- Engines: Lycoming VO-435-A1F 260 horsepower reciprocating
- Damage: Destroyed
- Fire: On-Ground
- Flight: Aerial application, Part 137
- Registered owner: Gerald K. Lewis
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, June 3, 1997

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 32; flight instructor, commercial; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 4,096 total, 260 in the last 90 days, 180 in the last 30 days, 9 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: variable at 4 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 91 °F, dew point 66 °F
- Altimeter: 29.00 inHg
- Observed at: BFL, 28 nm away

## 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 19970721019179A](https://openairdocs.org/incident/19970721019179A), Jul 21, 1997: Bell 47G2, Buttonwillow, CA, Destroyed. Going around a pole on spray run. Main rotors hit pole. Rolled over and burned.

## Other investigations on N919SF (3)

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 LAX93LA021](https://openairdocs.org/ntsb/LAX93LA021), Oct 31, 1992: Bell 47G2 (N919SF), Gonzales, CA, destroyed. Probable cause: THE PILOT'S FAILURE TO MAINTAIN ADEQUATE CLEARANCE FROM THE WIRES.
- [NTSB LAX75DUQ22](https://openairdocs.org/ntsb/LAX75DUQ22), Jan 25, 1975: Bell 47G-2 (N919SF), Arroyo Grande, CA, substantial damage
- [NTSB LAX72FUM17](https://openairdocs.org/ntsb/LAX72FUM17), Jan 1, 1972: Bell 47G-2 (N919SF), Chula Vista, 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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