Aircraft Accident/Incident Report

Gulkana, Alaska 99695
Thursday, January 14, 2010 10:30 AST

NTSB Narrative Summary Released at Completion of Accident

The commercial pilot was on a passenger flight when the accident occurred. The pilot said that, due to the cold outside temperature, he departed with the airplane's oil cooler cover in place. He said that the engine temperature increased and that he decided to land and remove the oil cooler cover. He then landed on a snow-covered lake and after landing he continued laying down tracks in the snow to aid in his departure. While laying down tracks the airplane's skis hit a ridge hidden under the snow. The pilot then examined the airplane and found that a fuselage frame tube had broken near the right main landing gear attachment. The pilot said that there were no mechanical problems with the airplane prior to the accident.

NTSB Probable Cause Narrative

The pilot's selection of unsuitable terrain for landing, which resulted in structural damage to the airplane during landing.

Event Information

Type of Event Accident
Event Date 1/14/2010
Event Day of the Week Thursday
Time of Event 1030
Event Time Zone Atlantic Standard Time
Event City Gulkana
Event State ALASKA
Event Country --
Zipcode of the event site 99695
Event Date Year 2010
Event Date Month 1
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude --
Event Location Longitude --
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 Weather Observation Facility
Time of the weather observation 953 Atlantic Standard Time
Direction of event from weather observation facility (degrees) 110
Weather Observation Facility ID GKN
Elevation of weather observation facility 1586
Distance of event from weather observation facility (units?) 15
Time Zone of the weather observation AST
Lighting Conditions Day
Lowest Ceiling Height --
Lowest Non-Ceiling Height 3500
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) 20
Air Temperature at event time (in degrees celsius) -23
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) 29.45
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 2
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 26698
NTSB Notification Source Operator
NTSB Notification Date --
NTSB Notification Time --
Fiche Number and/or location -used to find docket information --
Date of most recent change to record Mar 8 2010 1:25PM
User who most recently changed record stam
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N3233M
NTSB Number ANC10LA012
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 135: Air Taxi & Commuter
Type of Flight Plan filed Company VFR
Flight plan Was Activated? --
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name PIPER
Aircraft Model PA-12
Aircraft Series Identifier --
Aircraft Serial Number 12-2027
Certified Max Gross Weight 1950
Aircraft Category Airplane
Aircraft Registration Class --
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 3
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Annual
Date of Last Inspection Jul 16 2009 12:00AM
Airframe hours since last inspection --
Airframe Hours 3114
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site No
ELT Type C91-A
Aircraft Owner Name COPPER VALLEY AIR SERVICE LLC
Aircraft Owner Street Address PO BOX 234
Aircraft Owner City GLENNALLEN
Aircraft Owner State AK
Aircraft Owner Country USA
Aircraft Owner Zipcode 99588-0234
Operator is an individual? No
Operator Name COPPER VALLEY AIR SERVICE LLC
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address PO BOX 234
Operator City GLENNALLEN
Operator State AK
Operator Country USA
Operator Zip code 99588-0234
Operator Code UWPC
Owner has at least one certificate Yes - certificate holder
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation --
Operator Certificate Number UWPC450U
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 PAGK
Departure City Gulkana
Departure State AK
Departure Country USA
Departure Time 1030
Departure Time Zone AST
Destination Same as Local Flt --
Destination Airport Code PAMX
Destination City McCarthy
Destination State AK
Destination Country USA
Specific Phase of Flight --
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Mar 8 2010 1:26PM
User who most recently changed record stam
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 --