Aircraft Accident/Incident Report

Burlington, Wisconsin 53105
Saturday, August 11, 2012 16:00 CDT

NTSB Narrative Summary Released at Completion of Accident

The pilot departed on a local flight during which the airplane experienced an in-flight separation of the propeller. The pilot then performed a forced landing to a field that resulted in substantial damage to the fuselage. Postaccident examination of the airplane revealed that the pilot installed the propeller bolts backwards. The bolts were also found to be improperly torqued.

NTSB Probable Cause Narrative

The pilot's improper installation of the propeller bolts, which resulted in the in-flight separation of the propeller.

Event Information

Type of Event Accident
Event Date 8/11/2012
Event Day of the Week Saturday
Time of Event 1600
Event Time Zone Central Daylight Time
Event City Burlington
Event State WISCONSIN
Event Country --
Zipcode of the event site 53105
Event Date Year 2012
Event Date Month 8
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 --
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 1555 Central Daylight Time
Direction of event from weather observation facility (degrees) --
Weather Observation Facility ID BUU
Elevation of weather observation facility --
Distance of event from weather observation facility (units?) --
Time Zone of the weather observation CDT
Lighting Conditions Day
Lowest Ceiling Height --
Lowest Non-Ceiling Height 5500
Sky/Lowest/Cloud Conditions Clear
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) 23
Dew Point at event time (in degress fahrenheit) 8
Wind Direction (degrees magnetic) 10
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 5
Wind Velocity Indicator --
Wind Gust Indicator Not Gusting
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) 29.97
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report --
Event Highest Injury Minor
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal --
Injury Total Minor 2
Injury Total None --
Injury Total Serious --
Injury Total All 2
Investigating Agency NTSB
NTSB Docket Number (internal use) 31636
NTSB Notification Source --
NTSB Notification Date --
NTSB Notification Time --
Fiche Number and/or location -used to find docket information --
Date of most recent change to record Jul 22 2013 12:16PM
User who most recently changed record bowl
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N31TM
NTSB Number CEN12LA539
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? No
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name GN-1 AIRCAMPER
Aircraft Model MATHES
Aircraft Series Identifier --
Aircraft Serial Number 932
Certified Max Gross Weight --
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 630
ELT Installed Unknown
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type Unknown
Aircraft Owner Name Pilot
Aircraft Owner Street Address --
Aircraft Owner City Burlington
Aircraft Owner State WI
Aircraft Owner Country USA
Aircraft Owner Zipcode --
Operator is an individual? No
Operator Name Pilot
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address --
Operator City Burlington
Operator State WI
Operator Country USA
Operator Zip code --
Operator Code --
Owner has at least one certificate None
Other Operator of large aircraft? No
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) Personal
Second Pilot on Board No
Departure Point Same as Event No
Departure Airport Code BUU
Departure City Burlington
Departure State WI
Departure Country USA
Departure Time 1500
Departure Time Zone CDT
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code BUU
Destination City Burlington
Destination State WI
Destination Country USA
Specific Phase of Flight --
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Apr 23 2013 4:36PM
User who most recently changed record galm
Since inspection or accident Time of Accident
Event Location Runway Number and Location --
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --