Fergus Falls Muni-Einar Mickel Airport
Aircraft Accident/Incident Report

Fergus Falls, Minnesota 56537
Wednesday, June 20, 2007 8:00 CDT

NTSB Narrative Summary Released at Completion of Accident

The agricultural spray airplane sustained substantial damage during a forced landing following a severe engine vibration during cruise flight. The pilot reported that he was in cruise flight about 500 feet above ground level (agl) when the engine and airframe started to vibrate violently, and the windshield became covered with oil. He made a forced landing to a field, but the main landing gear broke off and the airplane flipped over. Inspection of the airplane revealed that one of the propeller blades was missing about 9 inches of the propeller blade tip. The propeller blade was cut and the piece with the fracture surface was sent to the National Transportation Safety Board's Materials Laboratory for examination. The inspection of the fracture surface revealed that the propeller bladed failed as a result of a fatigue crack, with features typical of impact of a rotating propeller blade with a foreign object. Aircraft maintenance records indicated that the propeller blade was repaired and overhauled on October 21, 2003. The overhaul documents indicated that the no discrepancies were found when the propeller blades and hub underwent visual and non-destructive testing. The aircraft operator reported that he had purchased the propeller blade from another operator as a "0" time blade since major overhaul. Since installing the propeller on the accident airplane, it had been flown for about 30 hours. The operator reported that the accident airplane did not have a propeller strike during the 30 hours of operation prior to the accident flight.

NTSB Probable Cause Narrative

The propeller blade failure during climb due to a fatigue crack. The oil leak that obstructed the pilot's vision was a factor in the accident.

Event Information

Type of Event Accident
Event Date 6/20/2007
Event Day of the Week Wednesday
Time of Event 800
Event Time Zone Central Daylight Time
Event City Fergus Falls
Event State MINNESOTA
Event Country --
Zipcode of the event site 56537
Event Date Year 2007
Event Date Month 6
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude --
Event Location Longitude --
Event Location Airport FERGUS FALLS MUNI-EINAR MICKEL
Event Location Nearest Airport ID FFM
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles 4
Degrees magnetic from airport --
Airport Elevation 1182
Weather Briefing Completeness --
Investigator's weather source Weather Observation Facility
Time of the weather observation 756 Central Daylight Time
Direction of event from weather observation facility (degrees) 135
Weather Observation Facility ID KFFM
Elevation of weather observation facility 1182
Distance of event from weather observation facility (units?) 4
Time Zone of the weather observation CDT
Lighting Conditions Day
Lowest Ceiling Height --
Lowest Non-Ceiling Height 8000
Sky/Lowest/Cloud Conditions Scattered
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) 19
Dew Point at event time (in degress fahrenheit) 14
Wind Direction (degrees magnetic) 260
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) 30.03
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 1
Injury Total None --
Injury Total Serious --
Injury Total All 1
Investigating Agency NTSB
NTSB Docket Number (internal use) 23151
NTSB Notification Source
NTSB Notification Date Jun 20 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 Federal Aviation Administration - MSP FSDO

Aircraft Involved

Aircraft #1

Aircraft Registration Number N23667
NTSB Number CHI07LA173
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 137: Agricultural
Type of Flight Plan filed None
Flight plan Was Activated? No
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Air Tractor
Aircraft Model AT-301
Aircraft Series Identifier --
Aircraft Serial Number 301-0410
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 1
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Annual
Date of Last Inspection Jun 1 2007 12:00AM
Airframe hours since last inspection --
Airframe Hours 5981
ELT Installed No
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name West Central Aerial Sprayers Inc
Aircraft Owner Street Address 1315 Hillcrest Ct
Aircraft Owner City Fergus Falls
Aircraft Owner State MN
Aircraft Owner Country USA
Aircraft Owner Zipcode 56537
Operator is an individual? No
Operator Name --
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address PO Box 178
Operator City Fergus Falls
Operator State MN
Operator Country USA
Operator Zip code 56537
Operator Code KMCG
Owner has at least one certificate --
Other Operator of large aircraft? --
Certified for Part 133 or 137 Operation Agriculture
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) Aerial Application
Second Pilot on Board No
Departure Point Same as Event No
Departure Airport Code FFM
Departure City FERGUS FALLS
Departure State MN
Departure Country USA
Departure Time 750
Departure Time Zone CDT
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 Emergency descent/landing
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Feb 22 2008 4:52PM
User who most recently changed record BOWL
Since inspection or accident Last Inspection
Event Location Runway Number and Location NA
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --