Bell 47G-3B-2 N4029G

Summary

On 24 July 2008 at about 16:00 local time, a Bell 47G-3B-2 registered N4029G, operated by Townsend Aviation Inc., was involved in an accident near Lafetyette, Indiana, 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

24 July 2008 at 16:00

Classification

Accident

Location

Lafetyette, Indiana, United States

Coordinates

40.4594, -86.7536

Aircraft

Bell 47G-3B-2

Registration

N4029G

Category

Helicopter

Engines

1

Operator

Townsend Aviation Inc.

Operating rule

Part 137: Agricultural

Purpose of flight

Aerial Application

Phase of flight

Not recorded

Route

Lafetyette → Laffetyette

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

CHI08CA210

Nobody was injured.

The loss of engine power during an aerial application flight due to a fatigue fracture of the carburetor heat control valve spring and the inadequate maintenance inspection by the pilot/mechanic. An additional cause was the low altitude of the operation.

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

Read the full NTSB narrative

The helicopter began losing engine power during an aerial application run while maneuvering. The pilot attempted a landing in the field and the helicopter impacted terrain about 80 yards from an access road at the north edge of the field. The helicopter sustained substantial damage. The pilot was uninjured. Examination of the helicopter revealed that the carburetor heat control spring that keeps the carburetor closed was broken and its support rod had worn into the housing. The heat valve could only be opened about 1/3 and while corresponding cockpit control remained in the closed position. The fracture surface of the spring was consistent with fatigue. The spring had accumulated a total time in service of 832 hours. The pilot was a certificated aircraft mechanic who also performed maintenance on the helicopter. A National Transportation Safety Board Pilot/Operator Aircraft Accident/Incident Report was not received from the pilot.

Quoted verbatim from the NTSB record.