- Date
- April 21, 2012, 15:00 local (23:00 UTC)
- Place
- Palmer, AK
- Injuries
- 1 uninjured
- Damage
- Substantial damage
- Phase of flight
- Standing
- Aircraft
- N121MRRobinson Helicopter R22 Alpha
- Defining event
- Standing-engine(s) operating: Loss of control on ground
- Weather
- Visual (VMC) · Day
- Status
- Completed · report July 18, 2012
- Report
- Approved by Office Director
- NTSB office
- Alaska Regional Office
- Parties
- FAA Anchorage FSDO-03
- FAA report
- 20120421007209A
- Case key
- 83452
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
The pilot's selection of unsuitable terrain for landing, which resulted in a tailrotor strike.
Findings · 2
NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.
Sequence of events
The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.
Analysis
The pilot flew to a practice area and landed the helicopter on what the pilot thought was firm snow. As he landed, the helicopter suddenly broke through the surface and its tailrotor struck the snow. The pilot repositioned the helicopter and the tailrotor gearbox chip detector light illuminated. An examination showed that the tailrotor driveshaft had sheared.
Factual narrative
The pilot flew to a practice area and landed the helicopter on what the pilot thought was firm snow. As he landed, the helicopter suddenly broke through the surface, and its tailrotor struck the snow. The pilot repositioned the helicopter, and the tailrotor chip light illuminated. An inspection showed that the tailrotor driveshaft had sheared.
Aircraft
- Registration
- N121MR
- Reported as
- Robinson Helicopter R22 Alpha
- Category
- Helicopter
- Serial number
- 0496
- Airframe hours
- 2,451
- Engine
- Lycoming O-320 A2B, 160 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Personal · Part 91
- Operator
- Pollux Aviation Limited, doing business as Pollux Aviation
- Registered owner
- Castor Aviation Ltd
- Airworthiness certificate
- Standard, Normal
- Last inspection
- 100 hour · April 18, 2012
- Departed
- 4AK6 · Palmer, AK
- Destination
- 4AK6 · Palmer, AK
- Flight plan
- Company VFR
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 33
- Injuries
- None
- Certificates
- Flight instructor, Commercial
- Instrument ratings
- Helicopter
- Medical
- Class 2, Without waivers/limitations
- Last flight review
- July 16, 2010
- Seat
- Right
- Flight hours
- 1,295 total · 1,176 in this make and model · 1,212 as pilot in command · 14 in the last 90 days · 12 in the last 30 days · 1 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- Calm
- Visibility
- 10 statute miles
- Lowest ceiling
- None
Docket · 1
The files NTSB released with the investigation on May 25, 2012, on NTSB’s docket system: statements, records, photos and specialists’ reports. 2.7 MB in all.
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.
Other investigations on N121MR · 1
Matched to the same aircraft by N-number and date.