Airworthiness Directive · Amendment 39-17525 · Pratt & Whitney Division Turbofan Engines
Pratt & Whitney Division Turbofan Engines
Superseded. A later AD replaced this one: AD 2014-23-01. Comply with the one in force.
This AD applies to all Pratt & Whitney Division (PW) turbofan engine models PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 with second-stage high-pressure turbine (HPT) air seal, part number 54L041, installed.
We are adopting a new airworthiness directive (AD) for all Pratt & Whitney Division (PW) turbofan engine model PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 with a certain second- stage high-pressure turbine (HPT) air seal part number installed. This AD was prompted by discovery of cracks in second-stage HPT air seals. This AD requires inspection and removal from service of HPT air seals that fail inspection. We are issuing this AD to prevent failure of the second-stage HPT air seal, which could lead to an uncontained engine failure and damage to the airplane.
(1) For second-stage HPT air seals that have 1,200 or fewer cycles since new (CSN) on the effective date of this AD, perform an initial on-wing eddy current inspection (ECI) or initial in-shop fluorescent-penetrant inspection (FPI) for cracks within 2,200 CSN.
(2) For second-stage HPT air seals that have more than 1,200 CSN on the effective date of this AD, perform an initial on-wing ECI or initial in-shop FPI for cracks within 1,000 cycles after the effective date of this AD.
(3) Thereafter, repeat either the on-wing ECI or in-shop FPI every 1,200 cycles or fewer, since last inspection, depending on the results of the inspection.
(4) For the on-wing ECI, use section 4.0 of the Appendix of PW Alert Service Bulletin (ASB) No. PW4G-112-A72-330, Revision 2, dated July 11, 2013, to perform the inspection and use paragraph 8 of the Accomplishment Instructions of PW ASB No. PW4G-112-A72-330, Revision 2, dated July 11, 2013, to disposition the results of the inspection.
(5) For the in-shop FPI, remove the air seal from service if you find a crack.
