NTSB Identification: CHI91LA215.
The docket is stored on NTSB microfiche number 44872.
Accident occurred Friday, July 05, 1991 in MENOMONEE FALLS, WI
Probable Cause Approval Date: 03/10/1993
Aircraft: CESSNA 182A, registration: N4735D
Injuries: 4 Uninjured.

NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

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.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

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

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