- Date
- July 24, 2008, 12:00 local (16:00 UTC)
- Place
- Lafetyette, IN
- Injuries
- 1 uninjured
- Damage
- Substantial damage
- Phase of flight
- Maneuvering
- Aircraft
- N4029GBell 47G-3B-2
- Defining event
- Maneuvering-low-alt flying: Loss of engine power (total)
- Weather
- Visual (VMC) · Day
- Status
- Completed · report September 26, 2008
- Report
- Approved by Office Director
- FAA report
- 20080724843519A
- Case key
- 68794
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
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.
Findings · 2
NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.
Sequence of events
The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.
Analysis
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.
Factual narrative
The helicopter began losing engine power during an aerial application while maneuvering. The pilot attempted a landing in the field where 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 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.
Aircraft
- Registration
- N4029G
- Reported as
- Bell 47G-3B-2
- Category
- Helicopter
- Serial number
- 6700
- Engine
- Lycoming TVO-435, reciprocating
- Damage
- Substantial damage
- Flight
- Aerial application · Part 137
- Operator
- Townsend Aviation Inc.
- Registered owner
- Wildhorse Helicopters Inc.
- Airworthiness certificate
- Special, Restricted (Special)
- Departed
- Lafetyette, IN
- Destination
- Laffetyette, IN
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 32
- Certificate
- Commercial
- Airplane ratings
- Single-engine land, Multi-engine land
- Instrument ratings
- Helicopter, Airplane
- Medical
- Class 2
- Flight hours
- 1,200 total · 100 in this make and model
Weather
- Conditions
- Visual (VMC) · Day
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.