Aircraft Accident/Incident Report

Ambler, Alaska 99786
Monday, June 27, 2011 9:25 AKD

NTSB Narrative Summary Released at Completion of Accident

The helicopter pilot landed a high skid, turbine-powered helicopter at a remote drilling site, and the three passengers disembarked. The remote landing site was constructed of 6-inch by 6-inch wooden beams, which required that the pilot land perpendicular to and on the beams with the helicopter's skids. The pilot reported that after landing he retarded the engine throttle to flight idle to begin the mandatory 2 minute engine cool down procedure. He then got out of the helicopter to check the placement of the helicopter's skids on the beams, and it subsequently tipped backwards, with the tail rotor striking terrain. A postaccident inspection revealed that while landing, the pilot inadvertently placed the helicopter's skids behind the aft wooden beam, and the helicopter tipped backwards once the pilot exited the helicopter. The pilot said there were no preimpact mechanical problems with the helicopter. The helicopter sustained substantial damage to the tail boom, tail rotor drive system, and tail rotor gearbox.

NTSB Probable Cause Narrative

The pilot's misalignment of the helicopter on the landing structure.

Event Information

Type of Event Accident
Event Date 6/27/2011
Event Day of the Week Monday
Time of Event 925
Event Time Zone --
Event City Ambler
Event State ALASKA
Event Country --
Zipcode of the event site 99786
Event Date Year 2011
Event Date Month 6
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 670600N
Event Location Longitude 1575100W
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 500
Sky/Lowest/Cloud Conditions Few
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 30
Air Temperature at event time (in degrees celsius) --
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) --
Variable Wind Indicator Variable
Wind Speed (knots) --
Wind Velocity Indicator Light and Variable
Wind Gust Indicator Not Gusting
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) 28765
NTSB Notification Source ANC FAA ROC
NTSB Notification Date --
NTSB Notification Time --
Fiche Number and/or location -used to find docket information --
Date of most recent change to record Sep 22 2011 6:37AM
User who most recently changed record johb
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number C-GLHQ
NTSB Number ANC11CA056
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 135: Air Taxi & Commuter
Type of Flight Plan filed Unknown
Flight plan Was Activated? --
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name HUGHES
Aircraft Model 500D
Aircraft Series Identifier --
Aircraft Serial Number 200662D
Certified Max Gross Weight --
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 --
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection --
Airframe hours since last inspection 98
Airframe Hours 18753
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site No
ELT Type C126
Aircraft Owner Name Prism Helicopters
Aircraft Owner Street Address --
Aircraft Owner City Wasilla
Aircraft Owner State AK
Aircraft Owner Country USA
Aircraft Owner Zipcode 99687
Operator is an individual? No
Operator Name Prism Helicopters
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address --
Operator City Wasilla
Operator State AK
Operator Country USA
Operator Zip code 99687
Operator Code --
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 --
Indicates whether an air carrier operation was scheduled or not Non-scheduled
Indicates Domestic or International Flight Domestic
Operator carrying Pax/Cargo/Mail Passenger Only
Type of Flying (Per_Bus / Primary) --
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code --
Departure City Ambler
Departure State AK
Departure Country USA
Departure Time 910
Departure Time Zone ADT
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code --
Destination City Ambler
Destination State AK
Destination Country USA
Specific Phase of Flight --
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Dec 9 2011 1:08PM
User who most recently changed record broda
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 --