Aviation Accident Summaries

Aviation Accident Summary ATL03LA007

Highfalls, GA, USA

Aircraft #1

N4002G

Bell 47G3B1

Analysis

A commercial pilot was completing his timber spraying operation and returning to the staging area. While at cruise flight the pilot felt a surge of engine power followed by a complete loss of power. The pilot selected a forced landing area and entered an autorotation. The helicopter collided with trees in a heavily wooded area. After the helicopter came to rest, the pilot removed the fuel filters to examine them for contamination, but was unable to make that determination. On recovery of the helicopter no fuel was found in the fuel tanks, and the helicopter was not equipped with a fuel quantity gauge for each tank as required by Federal Regulations. No other mechanical or flight control malfunctions were found with the helicopter.

Factual Information

On October 19, 2002, at 0930 eastern daylight time, a Bell 47G3B1, N4002G, registered to and operated by Holcomb Aerial Services, collided with trees during an autorotation near Highfalls, Georgia. The agricultural flight was operated under the provisions of Title 14 Part 137 and visual flight rules. Visual meteorological conditions prevailed at the time of the accident. The helicopter sustained substantial damage, and the commercial pilot was not injured. The flight departed a field near Highfalls, Georgia, on October 19, 2002 at 0900. The commercial pilot was completing his timber spraying operation and returning to the staging area. While at cruise flight the pilot felt a surge of engine power followed by a complete loss of power. The pilot selected a forced landing area and entered an autorotation. The pilot stated that the engine regained power during the forced landing. The helicopter collided with trees in a heavily wooded area. After the helicopter came to rest, the pilot removed the fuel filters to examine them for contamination, but was unable to make that determination. According to the pilot, 30 gallons of fuel was on board at the beginning of the flight and the flight lasted 25 minutes. Examination of the Bell 47 operator's manual revealed the Bell 47 burns approximately 25 gallons of fuel per hour. No fuel was found in the fuel tanks during recovery of the helicopter at the accident site. Examination of the helicopter revealed both skids were separated from the airframe. The pilot's windscreen was broken. The tail boom separated from the main fuselage, and the main rotor blades were buckled. The helicopter was moved to a recovery facility for further examination. Fuel was added to both fuel tanks, and no leaks were noted. Electrical power was supplied to the helicopter, and the engine was started and operated normally for a period of ten minutes. There were no fuel quantity indicators in the cockpit. All engine control gauges were in the green operating range during the test run-up. No other mechanical malfunctions were found with the helicopter. Federal Aviation Regulations 14 CFR Part 91.205 (b) states: For visual flight rules during the day the following instruments are required: (9) Fuel gauge indicating the quantity of fuel in each tank.

Probable Cause and Findings

The pilots inadequate fuel management, and subsequent loss of engine power due to fuel exhaustion, and a in-flight collision with trees during an autorotation. A factor was the pilot's failure to insure that the required equipment (fuel gauge) was installed in the helicopter.

 

Source: NTSB Aviation Accident Database

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