NTSB Identification: CHI84LA286.
The docket is stored on NTSB microfiche number 26886.
Accident occurred Saturday, July 07, 1984 in JOLIET, IL
Aircraft: GILLMORE MONI, registration: N157LG
Injuries: 1 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.

THE PROP SEPARATED FROM THE ACFT AT APRX 500 FT AGL DURING THE INITIAL TAKEOFF CLIMB. A FORCED LANDING WAS MADE IN A CORN FIELD. THE PROP WAS ATTACHED BY MEANS OF 4 5/16 INCH BOLTS AND RETAINING NUTS. TWO OF THE FOUR BOLT PORTIONS REMAINING AFTER THE ACCIDENT WERE REMOVED. ONE OF WHICH WAS TESTED AND PROGRESSIVE FATIGUE WAS FOUND. THE KIT MANUFACTURER LATER ISSUED A SERVICE BULLETIN STATING THAT WITH THE NUTS PROPERLY TORQUED IT IS POSSIBLE FOR THE NUTS TO BOTTOM OUT ON THE BOLT THREADS WHICH WOULD RESULT IN THE BOLTS SHEARING. THE MANUFACTURER SUGGESTS INSTALLING WASHERS AT THE HEAD OF THE BOLT TO PREVENT THE NUT FROM BOTTOMING OUT.

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

PROPELLER SYSTEM/ACCESSORIES,HUB..FATIGUE

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

PROPELLER SYSTEM/ACCESSORIES,HUB..SEPARATION




Contributing Factors

INSUFFICIENT STANDARDS/REQUIREMENTS,AIRCRAFT..MANUFACTURER

Index for Jul1984 | Index of months