Bell 206B N211CS

Summary

On 1 March 2017 at about 18:30 local time, a Bell 206B registered N211CS, operated by West Valley Aviation Inc, was involved in an accident near Firebaugh, California, United States. One person was on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

1 March 2017 at 18:30

Classification

Accident

Location

Firebaugh, California, United States

Coordinates

36.8814, -120.4664

Aircraft

Bell 206B

Registration

N211CS

Category

Helicopter

Year built

1979

Engines

1

Operator

West Valley Aviation Inc

Operating rule

Part 137: Agricultural

Purpose of flight

Aerial Application

Phase of flight

Not recorded

Route

Firebaugh → Firebaugh

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR17LA071

Nobody was injured.

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.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

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.

Quoted verbatim from the NTSB record.