NTSB Identification: NYC91FA199.
The docket is stored on NTSB microfiche number 45657.
Accident occurred Saturday, August 03, 1991 in PLEASANTVILLE, NJ
Probable Cause Approval Date: 04/27/1993
Aircraft: BEECH C23, registration: N9375S
Injuries: 3 Fatal.

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 EXPERIENCED A POWER LOSS SHORTLY AFTER TAKEOFF WHILE OPERATING OVER A RESIDENTIAL AREA AT NIGHT. THE AIRPLANE STRUCK A TELEPHONE POLE, AND CRASHED AND BURNED IN A STREET. RECORDS INDICATE THE ENGINE HAD A PROP STRIKE AT 1828 HRS, WAS OVERHAULED AT 2164 HRS, AND OVERHAULED AGAIN AT 3407 HRS. THE ACCIDENT OCCURRED AT 3486 HRS. NO RECORDS WERE AVAILABLE FOR THE FIRST OVERHAUL, HOWEVER WHEN EXAMINED AT THE 2ND OVERHAUL THE CRANKSHAFT WAS FOUND TO BE UNDERSIZED BY .003 INCH.. THE CRANKSHAFT HAD FAILED AT THE REAR OF THE NUMBER 3 CRANKPIN. METALLURGICAL EXAMINATION FOUND THE FRACTURE ORIGINATED SUBSURFACE IN AN AREA OF STRESS. NITRIDING RESIDUE WAS FOUND IN CRACKS WHICH HAD NOT BEEN DETECTED BY NONDESTRUCTIVE TESTING. THE FAA DOES NOT REQUIRE THE CERTIFICATION OF NONDESTRUCTIVE TESTING OPERATORS.

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

A POWER LOSS DUE TO A FAILED CRANKSHAFT, WHILE OPERATING OVER UNSUITABLE TERRAIN. FACTORS RELATED TO THE ACCIDENT WERE, THE NIGHT CONDITIONS, THE FAILURE OF MAINTENANCE PERSONNEL TO DETECT THE CRACKS USING MAGNAFLUX INSPECTIONS, THE LACK OF ADEQUATE PROCEDURES/DIRECTIONS ON DETECTION OF CRACKS, AND THE LACK OF QUALIFICATIONS/CERTIFICATION FOR OPERATORS CONDUCTING NONDESTRUCTIVE TESTING.

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