Bell 47G-5A accident near Farmington, California, March 10, 1991
On March 10, 1991, a Bell 47G-5A (helicopter), registered N59403, was substantially damaged in an accident near Farmington, California. It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
THE CONTAMINATION OF THE ENGINE INDUCTION AIR FILTER. SOFT TERRAIN DURING THE TOUCHDOWN WAS A FACTOR IN THE ACCIDENT.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- March 10, 1991
- Place
- Farmington, California · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell 47G-5A · all 47G-5As on the register
- Registration
- N59403 · registry record · serial 25140
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
THE ENGINE POWER REDUCED DURING A PROCEDURE TURNAROUND AS THE AIRCRAFT WAS DISPENSING LIQUID FERTILIZER. THE HELICOPTER SETTLED INTO SOFT TERRAIN AND THE MAIN ROTOR BLADE SEVERED THE TAIL BOOM. THE HELICOPTER THEN IMPACTED THE GROUND. EXAMINATION OF THE ENGINE'S AIR FILTER DISCLOSED EVIDENCE OF LIQUID FERTILIZER CLOGGING THE FILTER.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
Pilot
- Certificate: commercial pilot
- Ratings: single-engine land; instrument: airplane; rotorcraft: helicopter
- Flight time: 10,000 hours in all; 20 in the last 90 days; 15 in the last 30 days; 10,000 as pilot in command
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: unk
The aircraft
- Last inspection: inspection type not recorded, January 2, 2000
- Maximum gross weight: 2,850 lb
- Seats: 3
- Landing gear: fixed
- Engine: Lycoming VO-435-81A (piston); 0 hours total
- Operator: Ag-Air, INC.
The flight
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Other NTSB records under N59403 the same tail number, which may have belonged to a different aircraft at the time
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.