Airworthiness Directives; Pratt & Whitney JT8D-7, -7A, -7B, -9, -9A, -11, -15, and -17 Turbofan Engines

요약

The FAA is superseding an existing airworthiness directive (AD) for Pratt & Whitney JT8D-1, -1A, -1B, -7, -7A, -7B, -9, -9A, -11, -15, and -17 turbofan engines with 2nd stage fan blades, part number (P/N) 433802, 645902, 759902, 695932, 678102, or 746402, installed. That AD currently requires initial and repetitive ultrasonic inspection (UI) and fluorescent penetrant inspection (FPI) of those P/N 2nd stage fan blades. This AD replaces the required FPI with eddy current inspection (ECI) on all affected 2nd stage fan blades and maintains the requirement of UI of the blade root attachment on some of the affected 2nd stage fan blades. This AD also introduces an optional terminating action to the repetitive blade inspections for certain engine models. This AD results from reports of 10 fractures of 2nd stage fan blades since AD 87-14-01R1 became effective. We are issuing this AD to prevent uncontained failure of 2nd stage fan blades, which could result in damage to the airplane.