NTSB Identification: CHI98FA323
14 CFR Part 91: General Aviation
Accident occurred Thursday, August 20, 1998 in SPENCER, IA
Probable Cause Approval Date: 06/21/2000
Aircraft: Bell 222, registration: N30SV
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 helicopter experienced an in-flight break-up when it was traveling at about 130 knots at 960 feet above the ground. The wreckage path was on a 090 heading between 0.8 to 1.2 miles west of the Spencer, Iowa, airport. Examination of the swashplate outer ring pins revealed a bending fatigue fracture occurred in the 'white' pin. The fatigue cracking originated in the undercut fillet radius adjacent to the head of the pin. The 'white' and 'red' bores and the 'red' pin (The white pin was not located) were checked for proper dimensions. The examination indicated an insufficient interference fit between the outer swashplate bores and the outer diameter of the swashplate ring pins.

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

The below standard (loose) fit of the 'white' swashplate outer ring pin resulting in fatigue and subsequent separation of the pin, and ultimately the in-flight breakup of the rotorcraft. A factor was the manufacturer's dissemination of the pin which did not meet dimensional standards.

Full narrative available

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