Aircraft Accident/Incident Report

Seward, Alaska 99664
Friday, September 23, 2011 13:30 AKD

NTSB Narrative Summary Released at Completion of Accident

The commercial helicopter pilot, with two passengers aboard, was supporting a snow survey crew atop an expansive, smooth, featureless, and snow-covered glacial ice field. This operation required brief stops at various predetermined sites along a prearranged route. When the pilot departed from one site en route to the next predetermined site, deteriorating weather conditions coupled with flat light conditions hampered his ability to see the topographical features of the ice field below. As the pilot slowed the helicopter to make a precautionary landing, the helicopter “touched down early.” After the initial touchdown, the pilot hover-taxied the helicopter to an area about 20 or 30 yards beyond the initial touchdown point, then he landed the helicopter in the deep snow. After landing, the helicopter tipped backwards as the aft portion of the skids settled into the deep snow, and the tail rotor blades subsequently struck the snow. The operator reported no preaccident mechanical problems with the helicopter. Before the helicopter could be ferried from the site, a maintenance technician inspected the helicopter for damage. Finding no apparent damage, the helicopter was started, ground run, and then hovered. While hovering, a tail rotor driveshaft coupling separated, and the pilot did a hovering autorotation back to the snow-covered ice field. As a result of the tail rotor driveshaft coupling separation, the helicopter sustained substantial damage to the tail rotor drive shaft assembly. The damage to the tail rotor drive shaft occurred as the helicopter was being ferried from the site, not during the original event. Most likely the drive shaft was degraded during the first landing, but it did not separate until the ferry flight.

NTSB Probable Cause Narrative

The pilot's failure to maintain clearance from snow-covered terrain during hover in deteriorating weather and flat light conditions, which resulted in a tail rotor strike.

Event Information

Type of Event Accident
Event Date 9/23/2011
Event Day of the Week Friday
Time of Event 1330
Event Time Zone --
Event City Seward
Event State ALASKA
Event Country --
Zipcode of the event site 99664
Event Date Year 2011
Event Date Month 9
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 600414N
Event Location Longitude 1495712W
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 500
Lowest Non-Ceiling Height 500
Sky/Lowest/Cloud Conditions Thin Overcast
Sky Condition for Lowest Ceiling Overcast
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 6
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 3
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 31014
NTSB Notification Source National Park Service
NTSB Notification Date --
NTSB Notification Time --
Fiche Number and/or location -used to find docket information --
Date of most recent change to record Apr 5 2013 9:45AM
User who most recently changed record johb
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N204PA
NTSB Number ANC11TA110
Missing Aircraft Indicator --
Federal Aviation Reg. Part Public Use
Type of Flight Plan filed VFR
Flight plan Was Activated? Yes
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name BELL
Aircraft Model 206 B3
Aircraft Series Identifier --
Aircraft Serial Number 1742
Certified Max Gross Weight 3200
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 5
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection Aug 13 2011 12:00AM
Airframe hours since last inspection --
Airframe Hours 13347
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site No
ELT Type C126
Aircraft Owner Name PATHFINDER LEASING INC
Aircraft Owner Street Address --
Aircraft Owner City HOMER
Aircraft Owner State AK
Aircraft Owner Country USA
Aircraft Owner Zipcode 99603-0149
Operator is an individual? No
Operator Name PATHFINDER AVIATION
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address --
Operator City Homer
Operator State AK
Operator Country USA
Operator Zip code 99603
Operator Code P3TA
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 P3TA192K
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 No
Departure Airport Code PAWD
Departure City Seward
Departure State AK
Departure Country USA
Departure Time 1100
Departure Time Zone ADT
Destination Same as Local Flt crash at destination city
Destination Airport Code --
Destination City Seward
Destination State AK
Destination Country USA
Specific Phase of Flight --
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Mar 20 2013 10:07AM
User who most recently changed record johb
Since inspection or accident --
Event Location Runway Number and Location N/A
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --