CEN21LA389 · Robinson Helicopter R22 BETA
1 Acadiana Helicopters Robinson Helicopter R22 BETA · Accident: system/component malfunction/failure (non-power) during landing
From New Iberia, LA to an unrecorded destination
Event
- NTSB case
- CEN21LA389
- 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
Robinson Helicopter R22 BETA
- Aircraft type
- Robinson R22
- 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
- N827SH
- Operator
- 1 Acadiana Helicopters
- Onboard fatalities
- Unknown
- Route
- From New Iberia, LATo not recorded
- Aircraft age
- About 16 years (built 2005)
- 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 91: General Aviation
- 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
- Landing · flare/touchdown
- 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
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
While attempting to land at a staging location for a planned aerial application flight, the helicopter began to rotate to the right. The pilot was unable to regain control. The helicopter skids impacted a dirt field, and the helicopter rolled over onto its right side. The helicopter sustained substantial damage to its main rotor blades and fuselage. Disassembly of the helicopter for recovery revealed the tail rotor output shaft was fractured into two pieces. Examination of the output shaft revealed the fracture occurred between the mating tapered roller bearing and the bevel gear. The bevel gear side surface displayed progressive crack arrest marks consistent with fatigue cracking. Due to smear damage on the other fracture, it could not be determined if the fatigue cracking was the result of unidirectional bending fatigue (one origin) or reverse bending fatigue (two origins).
The tail rotor output shaft function is to drive the tail rotor blades. A failed tail rotor output shaft would result in the loss of drive to the tail rotor blades, which in turn would cause a loss of tail rotor thrust to counter main rotor torque and loss of yaw control.
Probable cause
The loss of tail rotor drive due to a fatigue failure of the tail rotor gearbox output shaft, which resulted in a loss of control during landing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN21LA389
- Event ID
- 20210830103773
- Case number
- CEN21LA389
- 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: 8d8e113a6a20df7875aa352d248519eb5b1e7ca834cee602bc54561e1ea1cd61; retrieved 2026-09-16T14:28:02.433Z.