Airworthiness Directive · Amendment 39-16533 · Pratt & Whitney PW4000 Series Turbofan Engines
Pratt & Whitney PW4000 Series Turbofan Engines
This AD applies to the following Pratt & Whitney turbofan engines with a ring case configuration rear high-pressure compressor (HPC) installed, that includes a 9th stage compressor stator segment assembly with 24 slots. These engines are installed on, but not limited to, Boeing 747-400/-400F, 767-200/-300, and MD-11 airplanes, and Airbus A300-600, A310-300, A330-300, and A330-200 airplanes.
The FAA is adopting a new airworthiness directive (AD) for certain Pratt & Whitney PW4000 series turbofan engines. This AD requires initial and repetitive borescope inspections (BSI) or fluorescent penetrant inspections (FPI) for cracks in the anti-vortex tube (AVT) shelf slots on the 10th stage disk of the high-pressure compressor (HPC) drum rotor disk assembly. This AD results from 47 reports received since 2007 of HPC 10th stage disks found cracked in the AVT shelf slots during shop visit inspections. We are issuing this AD to prevent failure of the HPC 10th stage disk, uncontained engine failure, and damage to the airplane.
You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done.
For engines listed in paragraphs (c)(1) and (c)(3) of this AD, do the following:
(1) Remove the low-pressure turbine (LPT) shaft and borescope-inspect (BSI) for cracks in the AVT shelf slots on the 10th stage disk of the HPC drum rotor disk assembly; or
(2) Remove the HPC drum rotor disk assembly and fluorescent-penetrant inspect (FPI) for cracks in the AVT shelf slots on the 10th stage disk of the HPC drum rotor disk assembly.
(3) Perform the inspection:
(i) Within 7,200 cycles-in-service (CIS) since incorporation of any of the following Pratt & Whitney Service Bulletins: (SB) No. PW4ENG 72-755, SB No. PW4ENG 72-756, SB No. PW4ENG 72-757, SB No. PW4ENG 72-759, or SB No. PW4G-100-72-220; or
(ii) Within 1,000 CIS after the effective date of this AD, whichever occurs later.
(4) If a crack is found, remove the HPC drum rotor disk assembly from service.
(g) For engines listed in paragraph (c)(2) of this AD, do the following:
(1) Remove the LPT shaft and BSI for cracks in the AVT shelf slots on the 10th stage disk of the HPC drum rotor disk assembly; or
(2) Remove the HPC drum rotor disk assembly and FPI for cracks in the AVT shelf slots on the 10th stage disk of the HPC drum rotor disk assembly.
(3) Perform the inspection:
(i) Within 7,200 cycles-since-new; or
(ii) Within 1,000 CIS after the effective date of this AD, whichever occurs later.
(4) If a crack is found, remove the HPC drum rotor disk assembly from service.
Thereafter, perform a BSI or FPI for cracks in the AVT shelf slots on the 10th stage HPC disk of the HPC drum rotor disk assembly within every 7,200 cycles-since-last-inspection.
(i) If a crack is found, remove the HPC drum rotor disk assembly from service.
Use paragraphs 3.A through 3.H of the Accomplishment Instructions of Pratt & Whitney SB No. PW4ENG 72-799, Revision 1, dated October 14, 2010, to perform the BSIs for engines listed in paragraph(c)(1) of this AD.
(k) Use paragraphs 3.A through 3.H of the Accomplishment Instructions of Pratt & Whitney SB No. PW4G-100-72-226, dated April 22, 2010, to perform the BSIs for engines listed in paragraphs(c)(2) and (c)(3) of this AD.
As optional terminating action to the repetitive inspection requirements of this AD, install new 9th stage compressor stator segments, part number (P/N) 50S479-01, P/N 50S479-02, P/N 50S479-03, and P/N 50S479-04, and perform one of the following:
(1) At the time the new 9th stage compressor stator segments are installed, replace the HPC drum rotor disk assembly with a new, 0 cycle, HPC drum rotor disk assembly; or
(2) At the time the new 9th stage compressor stator segments are installed, replace the 10th stage HPC disk with a new, 0 cycle, 10th stage HPC disk; or
(3) Perform a one-time BSI or FPI for cracks in the AVT shelf slots on the 10th stage HPC disk of the HPC drum rotor disk assembly between 4,000 and 7,200 cycles-in-service since installation of the new 9th stage compressor stator segments.
(i) If a crack is found, remove the HPC drum rotor disk assembly from service.
(ii) If no crack is found, then no further inspections are required.
(4) Guidance on installation of the new 9th stage compressor stator segments can be found in Pratt & Whitney SB No. PW4ENG 72-801, Revision 1, dated September 8, 2010, for engines listed in paragraph(c)(1) of this AD and in Pratt & Whitney SB No. PW4G-100-72-225 dated April 20, 2010, for engines listed in paragraphs(c)(2) and (c)(3) of this AD.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
