The FAA proposed to amend 14 CFR part 39 by superseding AD 2009-01-01, Amendment 39-15779 (73 FR 80296, December 31, 2008), with a proposed AD. The proposed AD applies to CFM International, S.A. CFM56-5B series turbofan engines. We published the proposed AD in the Federal Register on December 21, 2009 (74 FR 67834). That action proposed to require continuous monitoring of EGT margin deterioration, removing FADEC software version 5.B.Q and earlier versions from the engine as mandatory terminating action to the repetitive recalculating and EGT monitoring for certain engine models, and removing other certain engine models from service if the EGT margin deterioration is greater than 75 C.
Examining the AD Docket
You may examine the AD docket on the Internet at http:// www.regulations.gov; or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this AD, the regulatoryevaluation, any comments received, and other information. The street address for the Docket Operations office (telephone (800) 647-5527) is provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.
Comments
We provided the public the opportunity to participate in the development of this AD. We have considered the comments received.
Request To Clarify Engine Replacement Requirements
One commenter, CFM International, S.A., requests that we change the proposed AD to state, in part: "For airplanes where both engines indicate more than 75 C EGT margin deterioration, within 150 CIS either remove one engine and replace it with an engine indicating less than 75 C EGT margin.''
We do not agree. When both installed engines have greater than 75 C EGT margin deterioration, the proposed AD no longer allows replacing one of the engines with an engine that has 75 C or less of EGT margin deterioration as a corrective action. We do not agree with the commenter's requested change, but we see an opportunity to clarify that the terminating action for this AD for certain engine models, is to remove FADEC software version 5.B.Q and earlier. For other engine models, the corrective action is to remove those engines from service that have greater than 75 C of EGT margin deterioration. We added this clarification to the Summary of this AD. We kept the same engine replacement requirements in this AD, as those in the proposed AD.
Request To Reference the Latest Version of Software
CFM International, S.A. requests that we reference the latest version of software to be installed, which is version 5.B.R.
We do not agree. We intentionally referenced the software versions needing to be removed but not the version to be installed, as that version could become superseded in the future. We did not change the AD.
Request To Correct the Service Information Reference
CFM International, S.A. requests that we correctthe service information reference in paragraph (k) to read "CFM International, S.A. Alert Service Bulletin No. CFM56-5B S/B 72-A0722, Revision 1, dated March 20, 2009.''
We agree. We changed the AD to reflect the new service information reference throughout the compliance section.
Request To Indent Sub-Paragraphs
CFM International, S.A. requests that we indent the proposed AD numbered sub-paragraphs, as this further distinguishes the unique terminating actions for each group of identified CFM56 engine models.
We do not agree. Rulemaking procedures require that we do not indent sub-paragraphs. We did not change the AD.
Request To Alleviate
Two private commenters request that the prohibition against using engine control software version 5.B.Q or earlier versions, be alleviated for the CFM56-5B/2P (dual annular combustor) family of engine models. One other commenter requests that we move the contents of paragraph (h) to paragraph (f). The commenters state that thecurrently available engine control software version for those engines is earlier than version 5.B.Q.
We partially agree. We clarified paragraph (h) to apply to only those engine models where terminating action includes engine control software. We also added a second prohibition paragraph to apply to only those engines listed in paragraph (g). However, we did not move the contents of paragraph (h) to paragraph (f).
Conclusion
We have carefully reviewed the available data, including the comments received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We have determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.
Costs of Compliance
We estimate that this AD will affect 397 engines installed on airplanes of U.S. registry. We also estimate that it will take about one work-hour to install FADEC software. The average labor rate is $80per work-hour. There are no required parts costs. Based on these figures, we estimate the total cost of the AD to U.S. operators to be $31,760.
Authority for This Rulemaking
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.
Regulatory Findings
We have determined that this AD will not have federalism implications under Executive Order 13132. This AD will 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.
For the reasons discussed above, I certify that this AD:
(1) Is not a "significant regulatory action'' under Executive Order 12866;
(2) Is not a "significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and
(3) 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.
We prepared a summary of the costs to comply with this AD and placed it in the AD Docket. You may get a copy of this summary at the address listed under ADDRESSES.
List of Subjects in 14 CFR Part 39Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration amends 14 CFR part 39 as follows:
PART 39--AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. The FAA amends Sec. 39.13 by removing Amendment 39-15779 (73 FR 80296, December 31, 2008) and by adding a new airworthiness directive, Amendment 39-16279, to read as follows: