Federal Aviation Administration (FAA), DOT.
Notice of proposed rulemaking (NPRM).
We propose to adopt a new airworthiness directive (AD) for all General Electric Company (GE) CF34–8C and CF34–8E turbofan engines with certain part numbers (P/N) of operability bleed valves (OBV) installed. This proposed AD was prompted by three failure events of ring lock fuel fittings on the OBV. Two of those events led to an engine fire. This proposed AD would require the affected OBVs be removed from service and replaced with OBVs eligible for installation. We are proposing this AD to prevent failure of OBV ring lock fuel fittings, engine fuel leakage, uncontrolled fire, and damage to the airplane.
We must receive comments on this proposed AD by February 11, 2013.
You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods:
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For service information identified in this proposed AD, contact General Electric, One Neumann Way, MD Y–75, Cincinnati, OH; phone: 513–552–2913; email:
You may examine the AD docket on the Internet at
John Frost, Aerospace Engineer, Engine & Propeller Directorate, FAA, 12 New England Executive Park, Burlington, MA 01803; phone: 781–238–7756; fax: 781–238–7199; email:
We invite you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under the
We will post all comments we receive, without change, to
We received reports of three failure events of OBV ring lock fuel fittings on GE CF34–8C turbofan engines. Two of those events led to an engine fire. Investigation revealed that the ring lock fittings failed due to fatigue caused by improper broaching of the OBV housing during manufacture, and, improper installation of the ring lock fittings during OBV assembly. GE CF34–8E turbofan engines also use the affected OBVs and would be affected by this proposed AD. This condition, if not corrected, could result in failure of OBV ring lock fuel fittings, engine fuel leakage, uncontrolled fire, and damage to the airplane.
We reviewed GE Service Bulletin (SB) No. CF34–8C–AL S/B 75–0017, dated September 14 2012. We also reviewed GE SB No. CF34–8E–AL S/B 75–0012, dated September 14, 2012. These bulletins describe procedures for removing from service OBVs having an affected P/N.
We are proposing this AD because we evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of the same type design.
This proposed AD would require for all GE CF34–8C and CF34–8E turbofan engines with an OBV P/N 4121T67P02, P/N 4121T67P03, P/N 4121T67P04, parts manufacturer approval (PMA) P/N 392155–2, PMA P/N 392155–3, or PMA P/N 392155–4 installed, removal of the OBV from service.
We estimate that this proposed AD would affect 300 engines installed on airplanes of U.S. registry. We also estimate that it would take about two hours per engine to perform the actions required by this proposed AD, and that the average labor rate is $85 per hour. Required parts would cost about $25,000 per engine. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $7,551,000.
Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII: Aviation Programs, describes in more detail the scope of the Agency's authority.
We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701: “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.
We determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government.
(1) Is not a “significant regulatory action” under Executive Order 12866,
(2) Is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979),
(3) Will not affect intrastate aviation in Alaska, and
(4) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:
1. The authority citation for part 39 continues to read as follows:
49 U.S.C. 106(g), 40113, 44701.
2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):
We must receive comments by February 11, 2013.
None.
This AD applies to General Electric Company (GE) CF34–8C1, CF34–8C5, CF34–8C5A1, CF34–8C5A2, CF34–8C5A3, CF34–8C5B1, CF34–8E2, CF34–8E2A1, CF34–8E5, CF34–8E5A1, CF34–8E5A2, CF34–8E6, and CF34–8E6A1 turbofan engines, with an operability bleed valve (OBV) part number (P/N) 4121T67P02, P/N 4121T67P03, P/N 4121T67P04, parts manufacturer approval (PMA) P/N 392155–2, PMA P/N 392155–3, or PMA P/N 392155–4, installed.
This AD was prompted by three failure events of ring lock fuel fittings on the OBV. Two of those events led to an engine fire. We are issuing this AD to prevent failure of OBV ring lock fuel fittings, engine fuel leakage, uncontrolled fire, and damage to the airplane.
Comply with this AD within the compliance times specified, unless already done.
(1) For OBVs with fewer than 6,000 operating hours since new on the effective date of this AD, remove the OBV from service before accumulating 12,000 operating hours since new, or within four years after the effective date of this AD, whichever occurs first.
(2) For OBVs with 6,000 or more operating hours since new on the effective date of this AD, remove the OBV from service before accumulating an additional 6,000 operating hours, or within two years after the effective date of this AD, whichever occurs first.
The Manager, Engine Certification Office, FAA, may approve AMOCs for this AD. Use the procedures found in 14 CFR 39.19 to make your request.
(1) For more information about this AD, contact John Frost, Aerospace Engineer, Engine & Propeller Directorate, FAA, 12 New England Executive Park, Burlington, MA 01803; phone: 781–238–7756; fax: 781–238–7199; email:
(2) Refer to GE SB No. CF34–8C–AL S/B 75–0017, dated September 14 2012, and SB No. CF34–8E–AL S/B 75–0012, dated September 14, 2012, for related information.
(3) For service information identified in this AD, contact General Electric, One Neumann Way, MD Y–75, Cincinnati, OH; phone: 513–552–2913; email: