ANC12CA111 · Robinson Helicopter R22 BETA II
Alpine Air Alaska Robinson Helicopter R22 BETA II · Accident: loss of control in flight during autorotation
From Merrill Field (PAMR) to Merrill Field (PAMR)
Event
- NTSB case
- ANC12CA111
- 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
Robinson Helicopter R22 BETA II
- 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
- N4171J
- Operator
- Alpine Air Alaska
- Onboard fatalities
- Unknown
- Route
- From Merrill Field (PAMR), Anchorage, AKTo Merrill Field (PAMR), Anchorage, AK
- Aircraft age
- Not recorded
- 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
- Autorotation
- 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 › Action/decision
- Personnel issues › Psychological
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The flight instructor was providing primary helicopter flight instruction to a student pilot. The instructor reported that while practicing a series of hovering autorotations, he inadvertently allowed the student pilot to drift to the left during the descent. The instructor then took control of the helicopter, applied right cyclic, and raised the collective slightly to level the helicopter and arrest the descent, but the helicopter started to descend with the right skid low. The instructor then added left cyclic and raised the collective further in an attempt to cushion the landing. The helicopter then drifted to the right as the right skid subsequently struck the ground. After touchdown, the helicopter’s skids slid over the asphalt surface before the right skid “caught,” the helicopter rolled to the right, and the main rotor blades struck the ground. The helicopter came to rest on its right side, sustaining substantial damage to the fuselage, tail boom, and main rotor drive system. The instructor reported that there were no preaccident mechanical problems with the helicopter that would have precluded normal operation. He also stated that the accident might have been avoided if he had taken corrective action sooner and with less input on the cyclic.
Probable cause
The flight instructor's inadequate supervision of the student pilot during a hovering autorotation, which resulted in a dynamic rollover.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ANC12CA111
- Event ID
- 20120926X03348
- Case number
- ANC12CA111
- 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. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2012-09-26.
- API snapshot SHA-256: e44ac1057520bf41d49e4ccec18d3e16e8bd934d018d28a0c68146c86f59a2f2; retrieved 2026-09-15T20:01:51.491Z.