Aircraft Accident/Incident Report

Palmer, Alaska 99645
Saturday, April 21, 2012 15:00 AKD

NTSB Narrative Summary Released at Completion of Accident

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.

NTSB Probable Cause Narrative

The pilot's selection of unsuitable terrain for landing, which resulted in a tailrotor strike.

Event Information

Type of Event Accident
Event Date 4/21/2012
Event Day of the Week Saturday
Time of Event 1500
Event Time Zone --
Event City Palmer
Event State ALASKA
Event Country --
Zipcode of the event site 99645
Event Date Year 2012
Event Date Month 4
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 614022N
Event Location Longitude 1492410W
Event Location Airport --
Event Location Nearest Airport ID --
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation --
Weather Briefing Completeness --
Investigator's weather source Pilot
Time of the weather observation
Direction of event from weather observation facility (degrees) --
Weather Observation Facility ID --
Elevation of weather observation facility --
Distance of event from weather observation facility (units?) --
Time Zone of the weather observation --
Lighting Conditions Day
Lowest Ceiling Height --
Lowest Non-Ceiling Height --
Sky/Lowest/Cloud Conditions Thin Overcast
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) --
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) --
Variable Wind Indicator --
Wind Speed (knots) --
Wind Velocity Indicator Calm
Wind Gust Indicator --
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) --
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal --
Injury Total Minor --
Injury Total None 1
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 29950
NTSB Notification Source FAA Anchorage, ROC
NTSB Notification Date --
NTSB Notification Time --
Fiche Number and/or location -used to find docket information --
Date of most recent change to record May 25 2012 12:15PM
User who most recently changed record stam
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N121MR
NTSB Number ANC12CA032
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed Company VFR
Flight plan Was Activated? --
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name ROBINSON HELICOPTER
Aircraft Model R22 ALPHA
Aircraft Series Identifier --
Aircraft Serial Number 0496
Certified Max Gross Weight 1370
Aircraft Category Helicopter
Aircraft Registration Class --
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 2
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection Apr 18 2012 12:00AM
Airframe hours since last inspection --
Airframe Hours 2451
ELT Installed No
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name CASTOR AVIATION LTD
Aircraft Owner Street Address 6540 E BEECHCRAFT RD
Aircraft Owner City WASILLA
Aircraft Owner State AK
Aircraft Owner Country USA
Aircraft Owner Zipcode 99654-9330
Operator is an individual? No
Operator Name POLLUX AVIATION LIMITED
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address --
Operator City Palmer
Operator State AK
Operator Country USA
Operator Zip code 99645
Operator Code UPXL
Owner has at least one certificate Yes - certificate holder
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation External Load
Operator Certificate Number UPXL093U
Indicates whether an air carrier operation was scheduled or not --
Indicates Domestic or International Flight --
Operator carrying Pax/Cargo/Mail --
Type of Flying (Per_Bus / Primary) Personal
Second Pilot on Board No
Departure Point Same as Event No
Departure Airport Code 4AK6
Departure City Palmer
Departure State AK
Departure Country USA
Departure Time 1440
Departure Time Zone ADT
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code 4AK6
Destination City Palmer
Destination State AK
Destination Country USA
Specific Phase of Flight --
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record May 25 2012 12:15PM
User who most recently changed record stam
Since inspection or accident Time of Accident
Event Location Runway Number and Location N/A
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --