Airworthiness Directive · Amendment 39-17194 · Pratt & Whitney Division Turbofan Engines
Pratt & Whitney Division Turbofan Engines
This AD applies to the following Pratt & Whitney Division (Pratt & Whitney) turbofan engines:
(1) PW4000-94″ engine models PW4052, PW4056, PW4060, PW4062, PW4062A, PW4152, PW4156A, PW4158, PW4460, and PW4462, including those models with any dash number suffix, with a high-pressure compressor (HPC) drum rotor disk assembly listed in Table 1 to paragraph (c) of this AD installed.
(2) PW4000-100″ engine models PW4164, PW4168, and PW4168A, with a HPC drum rotor disk assembly listed in Table 1 to paragraph (c) of this AD installed.
(3) PW4000-112″ engine models PW4074, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3, with a HPC drum rotor disk assembly listed in Table 1 to paragraph (c) of this AD installed.
| Engine models | Affected HPC drum rotor disk assembly part numbers |
|---|---|
| PW4000-94″ | 50H936; 50H936-002; 53H923-01; 53H923-001; 53H973-01; 53H973-001; 54H803-01; 54H803-001; 54H803-002; 56H013-01; 56H013-001; 58H236-01 |
| PW4000-100″ | 53H973-01; 53H973-001; 54H803-01; 54H803-001; 54H803-002; 56H013-01; 56H013-001; 58H236-01 |
| PW4000-112″ | 55H722-01; 55H410-01; 57H010-01; 57H210-01; 57H610-01; 57H910-01 |
We are superseding an existing airworthiness directive (AD) for all Pratt & Whitney Division (Pratt & Whitney) PW4052, PW4056, PW4060, PW4062, PW4062A, PW4074, PW4077, PW4077D, PW4084D, PW4090, PW4090-3, PW4152, PW4156A, PW4158, PW4164, PW4168, PW4168A, PW4460, and PW4462 turbofan engines. That AD currently requires initial and repetitive fluorescent penetrant inspections (FPI) for cracks in the blade loading and locking slots of the high-pressure compressor (HPC) drum rotor disk assembly rear drum. This new AD requires the same actions, requires replacement of the 13th, 14th, and 15th stage HPC seals with redesigned HPC seals as an additional action, and adds an optional terminating action to the repetitive inspection requirements by allowing replacement of the entire HPC drum rotor disk assembly with a redesigned HPC drum rotor disk assembly. This AD was prompted by Pratt & Whitney developing a redesigned HPC drum rotor disk assembly for certain affected engine models. We are issuing this AD to prevent failure of the HPC drum rotor disk assembly, which could lead to an uncontained engine failure, and damage to the airplane.
(1) Perform a local fluorescent penetrant inspection for cracks in the HPC drum rotor disk assembly rear drum blade loading and locking slots of the specific stages of the HPC drum rotor disk assemblies from which any of the blades are removed as specified in Table 2 to paragraph (f) of this AD.
| For engine model | Inspect whenever... | To inspect, use... |
|---|---|---|
| PW4074, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 | Any of the HPC 13th or 14th stage blades are removed during a shop visit | Paragraphs 1.A. through 1.B. of the Accomplishment Instructions of PW4G-112-72-264, Revision 2, dated February 23, 2010. |
| PW4164, PW4168, and PW4168A | Any of the HPC 13th, 14th, or 15th stage blades are removed during a shop visit | Paragraphs 1.A. through 1.C of the Accomplishment Instructions of PW4G-100-72-186, Revision 1, dated September 2, 2004. |
| PW4052, PW4056, PW4060, PW4062, PW4062A, PW4152, PW4156A, PW4158, PW4460, and PW4462 | Any of the HPC 13th, 14th, or 15th stage blades are removed during a shop visit | Paragraphs 1.A. through 1.C. of the Accomplishment Instructions of PW4ENG 72-796, dated June 11, 2009. |
(2) Remove from service any HPC drum rotor disk assembly rear drum found with a crack in any of the blade loading and locking slots.
At the next piece-part exposure of the HPC drum rotor disk assembly after the effective date of this AD:
(1) Replace the 13th, 14th, and 15th stage HPC seals with redesigned HPC seals of engines listed in paragraph (c)(1) of this AD in accordance with paragraphs 1.A through 1.C of the Accomplishment Instructions of Pratt & Whitney Service Bulletin (SB) No. PW4ENG 72-816, Revision 1, dated June 12, 2012.
(2) Replace the 13th, 14th, and 15th stage HPC seals with redesigned HPC seals of engines listed in paragraph (c)(2) of this AD in accordance with paragraphs 1.A through 1.C of the Accomplishment Instructions of Pratt & Whitney SB No. PW4G-100-72-240, Revision 1, dated June 12, 2012.
As optional terminating action to the repetitive inspection requirements of this AD:
(1) Replace the HPC drum rotor disk assembly of engines listed in paragraph (c)(1) of this AD with a redesigned HPC drum rotor disk assembly in accordance with the Accomplishment Instructions of Pratt & Whitney SB No. PW4ENG 72-817, dated December 7, 2011.
(2) Replace the HPC drum rotor disk assembly of engines listed in paragraph (c)(2) of this AD with a redesigned HPC drum rotor disk assembly in accordance with the Accomplishment Instructions of Pratt & Whitney SB No. PW4G-100-72-241, dated November 15, 2011.
For the purpose of this AD, piece-part exposure means that the HPC drum rotor disk assembly is removed from the engine and completely disassembled.
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.
