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Action

Final rule.

Summary

We are adopting a new airworthiness directive (AD) for PW JT9D-7R4G2 and -7R4H1 turbofan engines. This AD was prompted by the determination that a new lower life limit for high-pressure turbine (HPT) 1st stage air seals, part number (P/N) 735907, is necessary. This AD establishes a new lower life limit for HPT 1st stage air seals, P/N 735907, and requires removing them from service using a drawdown schedule. We are issuing this AD to prevent critical life-limited rotating engine part failure and damage to the airplane.

Document

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