Aircraft Accident/Incident Report

Big Lake, Alaska 99652
Saturday, August 18, 2007 10:45 AKD

NTSB Narrative Summary Released at Completion of Accident

The local instructional flight was on an extended, low power descending approach to a remote airstrip when the engine lost power. Remedial actions to restore engine power, including pulling the carburetor heat on, did not restore engine power. The flight instructor seated in the rear seat of the tandem, two seat airplane, realized the airplane was too low to reach the airstrip, and he took the controls from the front seat pilot. The instructor made an off-airport emergency landing in soft terrain, and the airplane nosed over. Postaccident inspection disclosed ample fuel and no preimpact mechanical problems. The front seat pilot related that he did not have the carburetor heat on until the loss of engine power occurred, and the instructor told him to turn it on. He also said that there were low, wispy clouds in the area. A local weather report indicated that the temperature was 57F, and the dew point was 52F. When these values are entered into a carburetor icing probability chart, the results are in the "Serious Icing" category. Carburetor ice likely formed inside the carburetor, which resulted in the loss of engine power. Carburetor heat becomes ineffective once the engine has lost power.

NTSB Probable Cause Narrative

The flight instructor's delayed instructions to apply the carburetor heat, and his inadequate supervision. A factor contributing to the accident was carburetor icing conditions.

Event Information

Type of Event Accident
Event Date 8/18/2007
Event Day of the Week Saturday
Time of Event 1045
Event Time Zone --
Event City Big Lake
Event State ALASKA
Event Country --
Zipcode of the event site 99652
Event Date Year 2007
Event Date Month 8
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 612340N
Event Location Longitude 1495044W
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 1036 Atlantic Daylight Time
Direction of event from weather observation facility (degrees) 45
Weather Observation Facility ID PAWS
Elevation of weather observation facility --
Distance of event from weather observation facility (units?) 14
Time Zone of the weather observation ADT
Lighting Conditions Day
Lowest Ceiling Height --
Lowest Non-Ceiling Height --
Sky/Lowest/Cloud Conditions Clear
Sky Condition for Lowest Ceiling --
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 14
Dew Point at event time (in degress fahrenheit) 11
Wind Direction (degrees magnetic) --
Variable Wind Indicator --
Wind Speed (knots) --
Wind Velocity Indicator Calm
Wind Gust Indicator Not Gusting
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) 29.75
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) 23168
NTSB Notification Source ANC FAA ROC
NTSB Notification Date Aug 18 2007 12:00AM
NTSB Notification Time --
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record Mar 31 2008 11:52AM
User who most recently changed record NTSB\johb
Basic weather conditions Visual Meteorological Cond
FAA District Office Anchorage FSDO

Aircraft Involved

Aircraft #1

Aircraft Registration Number N98875
NTSB Number ANC07LA088
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Piper
Aircraft Model J-3
Aircraft Series Identifier --
Aircraft Serial Number 19135
Certified Max Gross Weight 1220
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 2
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Unknown
Date of Last Inspection --
Airframe hours since last inspection --
Airframe Hours --
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name James G. Breun
Aircraft Owner Street Address --
Aircraft Owner City Palmer
Aircraft Owner State AK
Aircraft Owner Country USA
Aircraft Owner Zipcode 99645
Operator is an individual? No
Operator Name --
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address --
Operator City --
Operator State --
Operator Country --
Operator Zip code --
Operator Code --
Owner has at least one certificate None
Other Operator of large aircraft? --
Certified for Part 133 or 137 Operation --
Operator Certificate Number --
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) Instructional
Second Pilot on Board Yes
Departure Point Same as Event No
Departure Airport Code Z41
Departure City Anchorage
Departure State AK
Departure Country USA
Departure Time 1020
Departure Time Zone ADT
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code --
Destination City --
Destination State --
Destination Country --
Specific Phase of Flight Approach - VFR pattern - turn to base
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Mar 5 2008 12:47PM
User who most recently changed record JOHB
Since inspection or accident --
Event Location Runway Number and Location NA
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --