CEN22LA318 · Hiller UH12E
Triple H Aviation Hiller UH12E · Accident: system/component malfunction/failure (non-power) while maneuvering
From Becker, MN to Becker, MN
Event
- NTSB case
- CEN22LA318
- 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
- Event fatalities
- Unknown
- 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
Hiller UH12E
- Aircraft type
- Hiller UH12
- 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
- N64272
- Operator
- Triple H Aviation
- Onboard fatalities
- Unknown
- Route
- From Becker, MNTo Becker, MN
- Aircraft age
- About 57 years (built 1965)
- 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
- System/component malfunction/failure (non-power)
- 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 propeller/rotor
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
While the pilot was conducting an aerial application flight, he felt a small jolt, the main rotor mast failed, and the helicopter collided with terrain.
Four days before the accident, a mechanic performed a dye penetrant inspection on the rotor mast; the helicopter had only flown 9 hours since the inspection.
Attempts to retrieve the rotor mast parts from the operator were unsuccessful and when contact was reestablished with the owner, he had already disposed of the parts. Photos of the broken rotor hub were reviewed by the National Transportation Safety Board (NTSB) Materials Laboratory, which determined that several preexisting, progressive cracks were present.
Probable cause
The in-flight failure of the main rotor mast hub due to several undetected fatigue fractures.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN22LA318
- Event ID
- 20220718105500
- Case number
- CEN22LA318
- 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: ab3ab06ecaff581c77fbfeb140bd45d3ad1b177c8c1773fc319b4c1916c0c806; retrieved 2026-09-16T15:27:59.400Z.