Airworthiness Directive · Amendment 39-19784 · Compressor bleed governor
General Electric Company Turbofan Engines
Superseded. A later AD replaced this one: AD 2022-09-14. Comply with the one in force.
This AD applies to all General Electric Company (GE) CF34-8C1, CF34-8C5, CF34-8C5A1, CF34-8C5B1, CF34-8C5A2, and CF34-8C5A3 model turbofan engines.
The FAA is superseding Airworthiness Directive (AD) 2017-23- 06, for certain General Electric Company (GE) CF34-8C1, CF34-8C5, CF34- 8C5A1, and CF34-8C5B1 engines. AD 2017-23-06 required an inspection of the bleed air manifold link rod assemblies and the supply, return, and drain fuel fittings on the operability bleed valve (OBV). This AD requires repetitive inspections of the OBV fuel tubes, OBV bleed air manifold link rod assemblies, and the OBV fuel fittings and replacement of OBVs or related hardware that fail inspection. In addition, this AD expands the applicability of these inspections to include additional GE CF34-8C model turbofan engines. This AD was prompted by multiple engine fires that have occurred as a result of malfunctions related to the OBV. The FAA is issuing this AD to address the unsafe condition on these products.
(1) For CF34-8C1, CF34-8C5, CF34-8C5A1, and CF34-8C5B1 model turbofan engines with serial numbers (S/Ns): 965101 through 965670 inclusive; 194101 through 194999 inclusive; and 195101 through 195653 inclusive:
(i) Perform an inspection of the OBV bleed air manifold link rod assemblies and the OBV fuel fittings within 500 flight hours after November 30, 2017 (effective date of AD 2017-23-06), or before next flight after the effective date of this AD, whichever occurs later.
(ii) Within 880 flight hours since the previous inspection, 500 flight hours from the effective date of this AD, or 6,880 flight hours since new, whichever occurs later, inspect the OBV bleed air manifold link rod assemblies, the OBV fuel fittings, and the OBV fuel tubes.
(iii) Thereafter, perform additional repeat inspections of the OBV bleed air manifold link rod assemblies, the OBV fuel fittings, and the OBV fuel tubes within every 880 flight hours since the previous inspection.
(iv) Use the Accomplishment Instructions, Paragraph 3.B., of GE CF34-8C S/B 75-0020, R04, dated May 10, 2019 (“the SB”), to perform the inspections in paragraphs (g)(1)(i) through (iii) of this AD and, per the criteria for the results of inspections in Paragraph 3.B. of the SB, do the following:
(A) Replace any OBV or fuel tube that is leaking and tighten or replace any loose OBV fuel tube clamps with a part eligible for installation before further flight.
(B) Replace any worn OBV link rod assembly hardware within 50 flight cycles after the inspection required by paragraphs (g)(1)(i), (ii), or (iii) of this AD. The engine can be returned to service each day for up to the 50 flight cycles if the OBV fittings are inspected each day for fuel leaks and looseness and, if they do not require removal based on the criteria in Table 1, “OBV Inspection,” of GE SB CF34-8C S/B 75-0020, R04, dated May 10, 2019.
(2) For CF34-8C5B1 model turbofan engines with S/Ns not listed in paragraph (g)(1) of this AD and for all CF34-8C5A2 and CF34-8C5A3 model turbofan engines, perform the following:
(i) For engines with 6,000 flight hours or more since new on the effective date of this AD, perform an initial inspection of the OBV bleed air manifold link rod assemblies, OBV fuel fittings, and OBV fuel tubes within 880 flight hours after the effective date of this AD.
(ii) For engines with less than 6,000 flight hours since new on the effective date of this AD, perform an initial inspection of the OBV bleed air manifold link rod assemblies, OBV fuel fittings, and OBV fuel tubes within 880 flight hours time in service or 6,880 flight hours since new, whichever occurs later.
(iii) Thereafter, repeat the inspection of the OBV bleed air manifold link rod assemblies, OBV fuel fittings, and OBV fuel tubes within 880 flight hours since the last inspection.
(iv) Use the Accomplishment Instructions, Paragraph 3.B., of GE CF34-8C S/B 75-0020, R04, dated May 10, 2019, to perform the inspections in paragraphs (g)(2)(i) through (iii) of this AD.
(v) Replace any parts according to the criteria in paragraph (g)(1)(iv) of this AD after the inspection required by paragraphs (g)(2)(i), (ii), or (iii) of this AD.
(3) For all affected engines, the reporting instructions in GE SB CF34-8C S/B 75-0020, R04, dated May 10, 2019, are not required by this AD.
