Probable cause
Maintenance personnel's improper inspection and cleaning of the fuel nozzle, which resulted in a total loss of engine power.
NTSB analysis
The pilot stated that as he approached a tree line for aerial application his chemical ran out. As he turned back to reload the chemical, the engine experienced a total loss of power. The pilot quickly conducted an autorotation and collided with trees before coming to rest on the ground. A postaccident examination of the engine revealed that the combustion chamber fuel spray nozzle was clogged with carbon and soot deposits, which is likely the result of the nozzle not being properly inspected and cleaned during the last 100-hour inspection. A review of the engine maintenance logbooks revealed that the last 100-hour inspection was completed 41 days prior to the accident. According to the aircraft Hobbs time, the engine accumulated 40 hours since the 100-hour inspection.
Text from the NTSB. Open the NTSB docket for ERA10LA383 for the full record.
Event
- Date
- Jul 29, 2010
- Type
- Accident
- Place
- Holly Hill, South Carolina
- Highest injury
- Serious
- Serious injuries
- 1
- Weather
- Visual (VMC)
- Light
- Day
Hiller UH-12E
- N-number
- N104HH
- Category
- Helicopter
- Damage
- Substantial
- Operating rule
- Part 137 (agricultural)
- Purpose of flight
- Aerial application
From the NTSB aviation accident database: N-registered aircraft, events since 2008, data through Oct 28, 2026. The file is published monthly, so the latest weeks are incomplete and recent records can change. The official source is the NTSB aviation investigation search. CheckAero is independent and not affiliated with the NTSB.