ANC21LA083 · McDonnell Douglas Helicopter 369E
McDonnell Douglas Helicopter 369E · Accident: roll over during takeoff
Event
- NTSB case
- ANC21LA083
- 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
- Charter & commuter
- 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
McDonnell Douglas Helicopter 369E
- Aircraft type
- McDonnell Douglas 369
- 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
- N125KW
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From not recordedTo not recorded
- Aircraft age
- About 32 years (built 1989)
- 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 135: Air Taxi & Commuter
- 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
- Roll over
- 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 › Action/decision
- Personnel issues › Task performance
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The pilot was transporting personnel from a remote helipad that was constructed of a plastic, floating dock. She was unaware that the helicopter’s right skid had slid under a portion of the plastic dock. As she raised the collective to depart, she felt the helicopter roll to the right, and she attempted to correct the lateral rolling motion by lowering the collective. The helicopter continued to roll and came to rest on its right side. Subsequently, the helicopter sustained substantial damage to the main rotor system.
The pilot reported no preimpact mechanical failures or malfunctions with the helicopter that would have precluded normal operation.
Probable cause
The pilot’s inability to maintain lateral control during the takeoff, which resulted in dynamic rollover. Contributing to the accident was the pilot’s decision to utilize an unsuitable landing area for flight operations.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ANC21LA083
- Event ID
- 20210907103817
- Case number
- ANC21LA083
- 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: local date, investigation status, coordinates, cause areas. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2021-09-07.
- API snapshot SHA-256: a2ebe74855619de71668f26c38c2dd4bab84a82f2a5935b37c6232a0a1822fa0; retrieved 2026-09-16T14:30:09.763Z.