CEN22LA351 · Bell Helicopter Textron 206B
Bell Helicopter Textron 206B · Accident: loss of engine power (total) while maneuvering
Event
- NTSB case
- CEN22LA351
- 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
- 0
- 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 Helicopter Textron 206B
- Aircraft type
- Bell 206
- 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
- N169AA
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From not recordedTo not recorded
- Aircraft age
- About 49 years (built 1973)
- 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
- 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
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot reported that he was completing an aerial application flight about 6 ft above the corn field when the engine sustained a loss of power. The helicopter descended into the corn and impacted the field. A small postcrash fire ensued near the engine and was extinguished.
Postaccident examination revealed all external air, fuel, and oil line connections were tight except for the pneumatic air line (Pc line) B-nut connecting the power turbine governor (PTG) to the fuel control unit (FCU). The Pc line was not connected to the FCU and a gap was noted between the B-nut and FCU union. Residual torque paint was identified; however, there was no new-effective torque paint identified on any B-Nut. It appeared the B-nut had backed off the FCU fitting. This Pc is one of several that use air pressure to communicate fuel scheduling demands between the PTG and FCU. The security of this line is necessary for proper engine operation. Operation of the engine without the B-nut properly connected would result in the FCU reducing fuel to a sub-idle condition, with the engine not capable of producing power for continued flight. There were no other mechanical functions or failures that would have precluded normal operation.
Maintenance was performed on the helicopter 23 days and 12 flight hours before the accident. It is likely that the maintenance personnel did not properly torque this B-but or apply torque stripe paint, which resulted in a disconnection of the B-nut and a loss of engine power.
Probable cause
Maintenance personnel’s failure to properly torque a fuel control unit B-nut, which resulted in a loss of engine power at low altitude and an impact with terrain.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN22LA351
- Event ID
- 20220802105642
- Case number
- CEN22LA351
- 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: d5eb06f8b9426ba3ea102fa4a526c0e3a818801028be1c4a9ae1bf10412b1829; retrieved 2026-09-16T15:32:31.617Z.