WPR24LA093 · Bell 47G-3B-1
English Air Service Bell 47G-3B-1 · Accident: loss of engine power (total) while maneuvering
From Santa Maria Public Airport Captain G Allan Hancock Field (SMX) to an unrecorded destination
Event
- NTSB case
- WPR24LA093
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Bell 47G-3B-1
- Aircraft type
- Bell 47
- Category
- Helicopter
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N2618W
- Operator
- English Air Service
- Onboard fatalities
- Unknown
- Route
- From Santa Maria Public Airport Captain G Allan Hancock Field (SMX), Santa Maria, CATo not recorded
- Aircraft age
- About 58 years (built 1966)
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 137: Agricultural
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Maneuvering · low-altitude flying
- Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Loss of engine power (total)
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Aircraft › Aircraft power plant
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot of the helicopter was applying a chemical to a field when the engine sustained a loss of power. The pilot entered an autorotation and the helicopter descended to the terrain, where it rolled onto its right side substantially damaging the main rotor system and severing the tailboom. Postaccident examination of the pneumatic air lines revealed that there was a slight air leak at the accumulator and a large air leak at a pneumatic air line (Pc) between the power turbine governor (PTG) and the fuel control unit (FCU); the Pc line was not connected to the FCU. The B-nut connecting the Pc line to the FCU had backed off, allowing the Pc line to become disconnected. . This Pc line is one of several lines that use air pressure to communicate fuel scheduling commands between the PTG and the FCU. The security of this line is necessary for proper engine operation. Engine operation without the Pc line properly connected would result in the FCU reducing fuel to a sub-idle condition, preventing the engine from producing sufficient power for continued flight. No other preaccident mechanical malfunctions or failures were found that would have precluded normal operation. Maintenance was performed on the helicopter 15 days and 29.2 flight hours before the accident that included checking all B-nuts for torque paint to ensure adequate torque remained on the B-nuts. Maintenance personnel likely did not properly inspect the condition of the torque paint on the affected B-nut, which resulted in a disconnection of the B-nut from the FCU and a total loss of engine power.
Probable cause
Maintenance personnel’s failure to properly check the torque paint on a fuel control unit B-nut, which resulted in the loosening of the B-nut, a loss of engine power at a low altitude, and a subsequent impact with terrain.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR24LA093
- Event ID
- 20240223193831
- Case number
- WPR24LA093
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status, cause areas. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: a3b75d9ef5174b0c4cacc4882f3a724a9a0e357de1c520f3b44195e3aa72e120; retrieved 2026-09-16T18:32:10.393Z.