airworthiness · Rule · Final rule. · Published 2012-03-23 · Effective 2012-04-27 · 77 FR 16916
Document
Document number
2012-6952
Federal Register citation
77 FR 16916
Type
Rule
Action
Final rule.
Category
airworthiness
Manufacturer
Pratt & Whitney (PW)Turbofan
Publication date
2012-03-23
Effective date
2012-04-27
FAA docket
Docket No. FAA-2011-1176
Abstract
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.