Summary
The FAA proposes to supersede 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 proposed AD would replace the required FPI with eddy current inspection (ECI) on all affected 2nd stage fan blades and would maintain the requirement of ultrasonic inspection (UI) of the blade root attachment on some of the affected 2nd stage fan blades. This proposed AD would also introduce an optional terminating action to the repetitive blade inspections for certain engine models. This proposed AD results from reports of 10 fractures of 2nd stage fan blades since AD 87-14-01R1 became effective. We are proposing this AD to prevent uncontained failureof 2nd stage fan blades, which could result in damage to the airplane.