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NTSB Report
July 5, 1991 · Cessna 182A · N4735D
Menomonee Falls, WI
Overview
Report Status
Probable Cause
Event Type
Accident
Date
July 5, 1991
Injury Outcomes
No injuries (4 uninjured)
Location
Menomonee Falls, WI
Aircraft
Cessna 182A
Tail Number
N4735D
Operator
Robert D Blanchard
Injuries
None
Aircraft Damage
Substantial
NTSB Number
CHI91LA215
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
THE FATIGUE INDUCED PROPELLER BLADE FAILURE. A RELATED FACTOR WAS THE OPERATOR'S DELAYED PROPELLER OVERHAUL.
Full Narrative
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.
Flight
Event TypeAccident
Event Time18:15 CDT
Nearest AirportAEROPARK (0nm N)
Runway18
Runway Length2600 ft
Runway Width50 ft
Flight Plan FiledNone
Aircraft FireNo
Aircraft ExplosionNo
Aircraft
AircraftCessna 182A
Tail NumberN4735D
Aircraft CategoryAir
DamageSubstantial
OperatorRobert D Blanchard
Operating RulePart 91
Engines1
Engine TypeReciprocating
Engine DetailsContinental · O-470-L · Reciprocating · 235
Seats1
People & Injuries
Injury SummaryNo injuries (4 uninjured)
Fatal0
Serious0
Minor0
Uninjured4
Total4
Crew 1Age 39 · Third Class
Conditions
ConditionsVMC
LightDaylight
WindCalm
Visibility15 sm
CeilingNone
Temperature / Dew Point0 C / 0 C
Altimeter0
Weather SourcePILO