Failure of inspection techniques at manufacture, assembly and in service were responsible for the Pratt & Whitney JT8D-200 fan-hub failure which killed two passengers on a Delta Air Lines McDonnell Douglas MD-88 in July 1996, according to findings from a US National Transportation Safety Board hearing. A minor flaw caused during manufacture at Volvo Flygmotor, when a hub tie-rod hole was drilled, later went unnoticed by P&W, and the resulting fatigue crack failed to show in Delta's dye-penetrant inspection, which have now been replaced by eddy-current techniques.
Source: Flight International
