Aeropark Airport
Aircraft Accident/Incident Report

Menomonee Falls, Wisconsin 53051
Friday, July 5, 1991 18:15 CDT

NTSB Narrative Summary Released at Completion of Accident

SHORTLY AFTER THE PILOT APPLIED FULL POWER FOR THE TAKEOFF GROUND ROLL, ONE PROPELLER BLADE FAILED AND SEPARATED FROM THE HUB ASSEMBLY. THE ENGINE THEN BROKE FREE OF THE ENGINE MOUNTS. POST ACCIDENT METALLURGICAL EXAMINATION OF THE PROPELLER BLADE AND HUB ASSEMBLY REVEALED THE FAILURE WAS DUE TO FATIGUE. THE POINT OF ORIGIN WAS THE FIRST THREAD OF THE THREADED HUB. THE PROPELLER HAD BEEN INSTALLED ON JULY 11, 1975, AND HAD ACCUMULATED 1227.57 HOURS AT THE TIME OF THE ACCIDENT. THE PROPELLER HAD NOT BEEN OVERHAULED. THE MANUFACTURER RECOMMENDS PROPELLER OVERHAUL AT INTERVALS NOT TO EXCEED 5 CALENDAR YEARS. AN AIRWORTHINESS DIRECTIVE EFFECTIVE 33 DAYS AFTER THE ACCIDENT REQUIRES A PENETRANT INSPECTION OF THE PROPELLER BLADE THREADED RETENTION AREA, AND A MODIFICATION OF THE PROPELLER ASSEMBLY FOR EARLY DETECTION OF FAILURE.

NTSB Probable Cause Narrative

THE FATIGUE INDUCED PROPELLER BLADE FAILURE. A RELATED FACTOR WAS THE OPERATOR'S DELAYED PROPELLER OVERHAUL.

Event Information

Type of Event Accident
Event Date 7/5/1991
Event Day of the Week Friday
Time of Event 1815
Event Time Zone Central Daylight Time
Event City MENOMONEE FALLS
Event State WISCONSIN
Event Country --
Zipcode of the event site 53051
Event Date Year 1991
Event Date Month 7
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport AEROPARK
Event Location Nearest Airport ID 76C
Indicates whether the acc/inc occurred off or on an airport On Airport
Distance from airport in statute miles 0
Degrees magnetic from airport 0
Airport Elevation 850
Weather Briefing Completeness Unknown
Investigator's weather source Pilot
Time of the weather observation 0
Direction of event from weather observation facility (degrees) 0
Weather Observation Facility ID
Elevation of weather observation facility 0
Distance of event from weather observation facility (units?) 0
Time Zone of the weather observation
Lighting Conditions Day
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 0
Sky/Lowest/Cloud Conditions Scattered
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 15
Air Temperature at event time (in degrees celsius) --
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) 0
Variable Wind Indicator Unknown
Wind Speed (knots) 0
Wind Velocity Indicator Light and Variable
Wind Gust Indicator Unknown
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) --
Density Altitude (feet) --
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor --
Injury Total None 4
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 1043
NTSB Notification Source --
NTSB Notification Date --
NTSB Notification Time 0
Fiche Number and/or location -used to find docket information 44872
Date of most recent change to record Dec 12 2000 10:31AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N4735D
NTSB Number CHI91LA215
Missing Aircraft Indicator N
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 CESSNA
Aircraft Model 182A
Aircraft Series Identifier 182A
Aircraft Serial Number 34835
Certified Max Gross Weight 2650
Aircraft Category Airplane
Aircraft Registration Class U.S. Registered/U.S. Soil
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 May 2 1991 12:00AM
Airframe hours since last inspection 90
Airframe Hours 4200
ELT Installed Yes
ELT Activated Yes
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name ROBERT D. BLANCHARD
Aircraft Owner Street Address 611 MAPLEWOOD DR.
Aircraft Owner City PLOVER
Aircraft Owner State WI
Aircraft Owner Country
Aircraft Owner Zipcode 54467
Operator is an individual? --
Operator Name ROBERT D. BLANCHARD
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address 611 MAPLEWOOD DR.
Operator City PLOVER
Operator State WI
Operator Country
Operator Zip code 54467
Operator Code
Owner has at least one certificate None
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation Unknown
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 Yes
Departure Airport Code
Departure City
Departure State
Departure Country
Departure Time 1815
Departure Time Zone CDT
Destination Same as Local Flt crash at destination city
Destination Airport Code
Destination City
Destination State
Destination Country
Specific Phase of Flight Takeoff
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:35AM
User who most recently changed record dbo
Since inspection or accident --
Event Location Runway Number and Location 18
Runway Length 2600
Runway Width 50
Sight Seeing flight No
Air Medical Flight No
Medical Flight --