Airworthiness Directive · Amendment 39-23081 · Turbine section
General Electric Company Engines
This AD applies to General Electric Company (GE) Model CF34-10E2A1, CF34-10E6, CF34-10E6A1, CF34-10E7, CF34-10E7-B, CF34-10E5, and CF34-10E5A1 engines with an installed high-pressure turbine (HPT) front rotating air seal having part number (P/N) 1865M49P04, 2448M30P02, or 2448M30P03.
The FAA is adopting a new airworthiness directive (AD) for certain General Electric Company (GE) Model CF34-10E2A1, CF34-10E6, CF34-10E6A1, CF34-10E7, CF34-10E7-B, CF34-10E5, and CF34-10E5A1 engines. This AD was prompted by a report of cracks found in the high- pressure turbine (HPT) front rotating air seal. This AD requires performing repetitive fluorescent penetrant inspections (FPIs) to detect indications or linear indications (any indication which is four times longer than the width of that same indication) in the HPT front rotating air seal and, if necessary, replacing the HPT front rotating air seal or HPT rotor disk with parts eligible for installation as applicable. This AD also includes an optional terminating action to the repetitive FPIs. The FAA is issuing this AD to address the unsafe condition on these products.
(1) At the next exposure of the HPT rotor assembly after the effective date of this AD and each exposure thereafter, perform a fluorescent penetrant inspection (FPI) of the HPT front rotating air seal for indications or linear indications in accordance with paragraphs 3.B.(1)(a) through (f), of GE CF34-10E Service Bulletin (SB) 72-0341 R02, dated September 24, 2021 (GE CF34-10E SB 72-0341 R02).
(2) If during any FPI required by paragraph (g)(1) of this AD, any indication greater than 0.015 in. (0.38mm) or any linear indication is found, before further flight, remove the HPT front rotating air seal from service and replace with a part eligible for installation, in accordance with paragraphs 3.B.(1)(g) and (h) of GE CF34-10E SB 72-0341 R02.
(3) If during any FPI required by paragraph (g)(1) of this AD, any indication is found that extends beyond the rabbet diameter M, as specified in paragraph 3.B.(1)(i), Figure 1, and Figure 4 (Sheet 2) of GE CF34-10E SB 72-0341 R02, before further flight, remove the HPT rotor disk from service and replace with a part eligible for installation, in accordance with paragraph 3.B.(1)(i)2 of GE CF34-10E SB 72-0341 R02.
Replacing the HPT front rotating air seal with an HPT front rotating air seal having P/N 2929M57P01 terminates the requirements of this AD.
For the purpose of this AD, the definitions in paragraphs (i)(1) through (3) of this AD apply:
(1) An “exposure of the HPT rotor assembly” is when the HPT rotor assembly
is removed from the core module assembly.
(2) A “linear indication” is any indication whose length is at least four times greater than its width.
(3) A “part eligible for installation” is defined as the following, as applicable:
(i) An HPT front rotating air seal that is eligible for installation is an HPT front rotating air seal having P/N 1865M49P04, P/N 2448M30P02, or P/N 2448M30P03 that has passed the inspection required by paragraph (g)(1) of this AD, or an HPT front rotating air seal having P/N 2929M57P01.
(ii) An HPT rotor disk that is eligible for installation is an HPT rotor disk having P/N 1865M51P03 or P/N 1865M51P04 that has not been removed from service as a result of the actions required by paragraph (g)(3) of this AD.
