Summary
The FAA proposes to supersede Airworthiness Directive (AD) 2011-07-02, which applies to all Pratt & Whitney (P&W) JT8D-209, JT8D- 217, JT8D-217A, JT8D-217C, and JT8D-219 model turbofan engines. AD 2011-07-02 requires initial and repetitive torque inspections of the 3rd-stage and 4th-stage low-pressure turbine (LPT) blades. AD 2011-07- 02 also requires replacement of the LPT blade if wear limits are exceeded, replacement of the LPT-to-exhaust case bolts and nuts, and installation of crushable sleeve spacers on the bolts. Since the FAA issued AD 2011-07-02, the FAA received a report of an MD-82 airplane, equipped with a JT8D-217 engine, experiencing an engine surge that resulted in the fracture of an LPT blade. This proposed AD would retain certain requirements of AD 2011-07-02, while revising the inspection thresholds and replacement intervals for the 3rd-stage and 4th-stage LPT blades. The FAA is proposing this AD to address the unsafe condition on these products.