ERA21LA121 · Robinson Helicopter Co R66
Robinson Helicopter Co R66 · Accident: loss of control in flight during takeoff
From an unrecorded airport to McGhee Tyson Airport (TYS)
Event
- NTSB case
- ERA21LA121
- 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 Co R66
- Aircraft type
- Robinson R66
- 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
- N660TN
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From not recordedTo McGhee Tyson Airport (TYS), Knoxville, TN
- Aircraft age
- About 7 years (built 2014)
- 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
- Takeoff
- 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 control in flight
- 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 oper/perf/capability
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot performed a preflight inspection of the helicopter, which was positioned in the yard of a residence on a slight incline. After starting the engine, and completing the checklist, he lifted to a hover at 6 ft. The helicopter then began to rotate in a counterclockwise direction and the helicopter’s nose pitched up. The rear portion of the right skid contacted the ground and the helicopter to rolled onto its right side. The helicopter’s main rotor, fuselage, and tailboom were substantially damaged. A posaccident examination of the helicopter revealed no evidence of any preimpact mechanical failures or malfunctions of the helicopter that would have precluded normal operation. Given this information, it is likely that the pilot failed to maintain directional control of the helicopter while transitioning into the hover, and the helicopter experienced a dynamic rollover when the right rear skid contacted the sloped ground.
Probable cause
The pilot’s failure to maintain directional control of the helicopter, which resulted in rear portion of the right skid contacting the ground and a subsequent dynamic rollover.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ERA21LA121
- Event ID
- 20210130102576
- Case number
- ERA21LA121
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (5)
- 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: 5945feefaee44f4c37486fe95deb775491e1a91f59ce3e937fc4a5e685545441; retrieved 2026-09-16T13:35:14.677Z.
- Corrected after a review of the NTSB narrative, which states these values explicitly: destination. TYS is McGhee Tyson Airport serving Knoxville, TN; the recorded city name is misspelled.