Airworthiness Directive · Amendment 39-19008 · Turbine engine compressor section
General Electric Company Turbofan Engines
This AD applies to General Electric Company (GE) CF34-8C1, CF34-8C5, CF34-8C5A1, CF34-8C5B1, CF34-8C5A2, CF34-8C5A3, CF34-8E2, CF34-8E2A1, CF34-8E5, CF34-8E5A1, CF34-8E5A2, CF34-8E6 and CF34-8E6A1 engines, including engines marked on the engine data plate as CF34-8C5B1/B, CF34-8C5/B, CF34-8C5A1/B, CF34-8C5A2/B, CF34-8C5/M, CF34-8C5A1/M, CF34-C8C5A2/M, CF34-8C5A3/B, or CF34-8C5B1/M, with a fan blade, part number (P/N) 4114T15P02 or P/N 4114T31G01, installed.
We are adopting a new airworthiness directive (AD) for certain General Electric Company (GE) CF34-8 model turbofan engines. This AD was prompted by analysis that resulted in the reduction of the life of the affected fan blades. This AD requires inspections of the affected fan blades until their removal. We are issuing this AD to address the unsafe condition on these products.
(1) For CF34-8C1, CF34-8C5B1, CF34-8C5B1/B and CF34-8E2 engines with fan blade, P/N 4114T15P02, installed:
(i) Perform an initial ECI of the fan blade pinhole prior to the fan blade accumulating 25,000 cycles-since-new (CSN); and
(ii) Repeat this inspection within every 3,000 cycles thereafter.
(2) For CF34-8C5, CF34-8C5/B, CF34-8C5A1, CF34-8C5A1/B, CF34-8C5A2, CF34-8C5A2/B, CF34-8E2A1, CF34-8E5, CF34-8E5A1, CF34-8E6 and CF34-8E6A1 engines with fan blade, P/N 4114T15P02, installed:
(i) Perform an initial ECI of the fan blade pinhole prior to the fan blade accumulating 19,500 CSN; and
(ii) Repeat this inspection within every 3,000 cycles thereafter, until the fan blade has accumulated 25,000 CSN, then repeat the inspection every 1,500 cycles thereafter.
(3) For CF34-8C5/M, CF34-8C5A1/M, CF34-8C5A2/M, CF34-8C5A3, CF34-8C5A3/B, CF34-8C5B1/M, and CF34-8E5A2 engines with fan blade, P/N 4114T15P02, installed:
(i) Perform an initial ECI of the fan blade pinhole prior to the fan blade accumulating 19,000 CSN; and
(ii) Repeat this inspection within every 3,000 cycles thereafter, until the fan blade has accumulated 25,000 CSN, then repeat the inspection every 1,500 cycles thereafter.
(4) For any affected engine with a fan blade, P/N 4114T15P02, installed, where the CSN of the fan blade is unknown on the effective date of this AD:
(i) Assume the blade has accumulated 25,000 CSN on the effective date of this AD; and
(ii) Inspect the blade prior to installation or within 500 cycles after the effective date of this AD, whichever is earlier.
(iii) Repeat this inspection based on the intervals of the new engine installation, as specified in paragraph (g) of this AD.
(5) If a fan blade is moved from one affected engine model to another affected model after the initial ECI:
(i) Perform an additional ECI of the blade prior to installation in the new model; and
(ii) Repeat this inspection based on the intervals of the new engine installation, as specified in paragraph (g) of this AD.
(6) If a fan blade, P/N 4114T15P02, has been used on more than one engine model prior to the initial ECI, use Appendix A of GE Alert Service Bulletin (ASB) CF34-8C SB 72-A0137, R05, dated June 15, 2016, or Appendix A of GE ASB CF34-8E SB 72-A0060, R05, dated June 15, 2016, to calculate the new cycle limit for the initial inspection of that fan blade.
(7) Guidance on performing the ECI can be found in GE Service Bulletins GE ASB CF34-8C SB 72-A0137, R05, dated June 15, 2016, or GE ASB CF34-8E SB 72-A0060, R05, dated June 15, 2016.
(1) For any affected engine with a fan blade, P/N 4114T15P02, installed, remove the blade from service or repair to P/N 4114T31G01 prior to the blade accumulating 41,000 CSN.
(2) For any affected engine with a fan blade, P/N 4114T31G01, installed, remove the blade from service prior to the blade accumulating 28,000 cycles since installation of the pinhole bushing.
