Bell 206B accident near Firebaugh, California, March 1, 2017
On March 1, 2017 at about 6:30 pm local time, a 1979 Bell 206B (helicopter), registered N211CS, was substantially damaged in an accident during maneuvering (low-alt flying) near Firebaugh, 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
A total loss of engine power due to fuel exhaustion. Contributing to the accident was the improper calibration of the fuel quantity gauge, which led the pilot to believe that there was adequate fuel onboard.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- March 1, 2017 · about 6:30 pm local time
- Place
- Firebaugh, California · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell 206B B, built 1979 · all 206Bs on the register
- Registration
- N211CS · registry record · serial 2775
- 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 commercial pilot of the helicopter reported that, while conducting an aerial application flight, he heard a loud bang followed by a total loss of engine power. The pilot initiated an autorotation to a plowed field; however, during the landing sequence, the main rotor blades struck the tailboom. Postaccident examination revealed that, when power was applied, the fuel quantity gauge indicated about 15 gallons of fuel when the actual amount present was about 6.5 gallons. This erroneous fuel level indication led the pilot to believe that more fuel was available than was actually in the fuel tanks. The helicopter flight manual indicated that, due to possible fuel sloshing in unusual attitudes or out-of-trim conditions, and one or both fuel pumps inoperative, the unusable fuel is 10 gallons. The engine was subsequently installed on a test stand and several test runs revealed no anomalies. Further testing revealed that the aft fuel boost pump was inoperative. The thermal fuse was found open, consistent with overheating due to the lack of fuel being transferred through the pump. It is likely that, during the flight, the attitude of the helicopter was slightly nose-down. This allowed the fuel to transfer to the forward portion of the tank, which resulted in a lack of fuel flow through the aft fuel pump; the subsequent overheating triggered the thermal fuse, which caused the aft fuel pump to become inoperative. It is likely that the total loss of engine power was the result of fuel exhaustion.
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
What happened, in order
- Loss of engine power (total) during maneuvering (low-alt flying) defining event
- Off-field or emergency landing during enroute (cruise)
- Autorotation Off-field or emergency landing
The NTSB's findings
- cause Aircraft › Fluids/misc hardware › Fluids › Fuel › Fluid management
- cause Aircraft › Fluids/misc hardware › Fluids › Fuel › Fluid level
- factor Aircraft › Aircraft systems › Fuel system › Fuel quantity indicator › Malfunction
- factor Aircraft › Aircraft systems › Fuel system › Fuel indication system › Malfunction
Pilot
- Certificate: commercial pilot
- Ratings: rotorcraft: helicopter
- Flight time: 4,599 hours in all; 4,200 in this make and model; 160 in the last 90 days; 100 in the last 30 days; 4,559 as pilot in command
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: rgt
- Injury: no injuries
The aircraft
- Last inspection: continuous airworthiness programme, February 22, 2017; 20 hours since
- Maximum gross weight: 3,201 lb
- Landing gear: fixed
- Engine: Rolls-Royce 250-C20B (turboshaft); 12,092 hours total
- Operator: West Valley Aviation INC
The flight
- Departed from: Firebaugh CA at 6:29 pm
- Destination: Firebaugh CA
- Flight plan: none
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 54°F (12°C), dew point 41°F (5°C)
- Altimeter: 30.42 inHg
- Observation at 6:53 pm from KMAE, 18 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
7 documents, released by the NTSB on July 5, 2018. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 13 pages | View Download |
| 2 | Bell Report | PDF, 3 pages | View Download |
| 3 | Rolls Royce Report | PDF, 14 pages | View Download |
| 4 | Parker Hannifin Fuel Pump Report | PDF, 48 pages | View Download |
| 5 | Portion of the Bell Helicopter Flight Manual | PDF, 1 page | View Download |
| 6 | Bell Helicopter Email Correspondence Regarding Flight Manual Usage | PDF, 1 page | View Download |
| 7 | Release of Aircraft Wreckage, NTSB Form 6120.15 | PDF, 1 page | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
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.