NTSB Identification: MKC82FCA08
14 CFR Part 91: General Aviation
Accident occurred Sunday, April 11, 1982 in ST GENEVIEVE, MO
Probable Cause Approval Date: 04/11/1983
Aircraft: BELL 47G-4, registration: N87623
Injuries: 2 Serious.

NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.

THE PILOT REPORTED THAT ABOUT 40 MINUTES AFTER TAKEOFF, THERE WAS A DROP IN OIL PRESSURE FOLLOWED ALMOST IMMEDIATELY BY AN ENGINE FAILURE. THE ENGINE FAILURE OCCURRED OVER A WOODED AREA. THE PILOT ATTEMPTED AN EMERGENCY LANDING IN A SMALL CLEARING, BUT THE HELICOPTER STRUCK TREES SHORT OF THE OPENING. AN INVESTIGATION REVEALED THAT THE NO. 5 CONNECTING ROD HAD FAILED AT THE CRANKSHAFT END. IT WAS NOTED THAT A ROD CAP BOLT HAD BROKEN, THE CAP HAD STRAIGHTENED OUT, AND THE ROD HAD SEPARATED FROM THE CRANKSHAFT. A LARGE HOLE WAS FOUND IN THE CRANKCASE AND THE OIL TANK WAS EMPTY. HOWEVER, OIL WAS NOTED INSIDE THE ENGINE AND ON ALL BEARINGS AND JOURNALS EXCEPT THE NO. 5 CONNECTING ROD. ALSO, ALL MAIN BEARINGS AND ALL ROD BEARINGS AND JOURNALS, EXCEPT NO. 5, WERE NORMAL.

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

ENGINE ASSEMBLY,CONNECTING ROD..UNDETERMINED



Contributing Factors

OBJECT..TREE(S)

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