CEN15LA370 · Bell 206B
Fly Hangar 13 Bell 206B · Accident: loss of engine power (total) while maneuvering
From Cresco, IA to Cresco, IA
Event
- NTSB case
- CEN15LA370
- 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 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
- N5743W
- Operator
- Fly Hangar 13
- Onboard fatalities
- Unknown
- Route
- From Cresco, IATo Cresco, IA
- Aircraft age
- About 35 years (built 1980)
- 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 from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The commercial pilot reported that the helicopter departed with 30 gallons of fuel and about 90 gallons of chemical to spray a soybean field. About 5 minutes into the application flight and while 3 to 5 ft above the soybeans, the pilot heard a loud screech for about 2 seconds and pulled up to gain altitude. The pilot then heard the low rotor rpm horn and noticed that the main rotor rpm was at 85 percent. The pilot initiated an autorotation to a waterway between two cornfields. Upon touchdown on uneven terrain, the main rotor blades contacted and severed the tailboom, and the helicopter then came to rest upright.
Disassembly of the engine revealed that the third-stage turbine wheel was missing five airfoils (blades), that several other airfoils were damaged, and that portions of the shroud were liberated. Materials examination of the third-stage turbine wheel revealed that the five airfoils had cracked in fatigue, initiating from the trailing edge root area and progressing forward until final fracture occurred in overload. All five cracks had initiated and progressed in high-cycle fatigue. Extensive testing by the engine manufacturer could not identify a single root cause for the liberation of the airfoils. As a result of the investigation, the engine manufacturer planned to release a new wheel design and process improvements to improve the robustness and capability of the turbine wheel.
Probable cause
The loss of engine power due to the high-cycle fatigue failure of the third-stage turbine wheel.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN15LA370
- Event ID
- 20150820X20604
- Case number
- CEN15LA370
- 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, coordinates. 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: 09dbb2a28665e57daacc688dd6c22aae55eedb3113370d6314eb8e402474ef3b; retrieved 2026-09-16T02:42:04.041Z.