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AGENCY: Federal Aviation Administration
(FAA), DOT.
ACTION: Final rule.
SUMMARY: The FAA is adopting a new airworthiness directive (AD)
for CFM International S.A. CFM56-2, CFM56-3, CFM56-5A, CFM56-5B, CFM56-5C,
and CFM56-7B series turbofan engines with certain part number (P/N) and
serial number (SN) high-pressure compressor (HPC) 4-9 spools installed.
This AD requires removing certain HPC 4-9 spools listed by P/N and SN
in this AD. This AD results from reports of certain HPC 4-9 spools that
Propulsion Technology LLC (PTLLC) improperly repaired and returned to
service. We are issuing this AD to prevent cracking of the HPC 4-9 spool,
which could result in possible uncontained failure of the spool and damage
to the airplane.
DATES: This AD becomes effective June 23, 2009.
ADDRESSES: The Docket Operations office is located at Docket Management
Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, SE.,
West Building Ground Floor, Room W12-140, Washington, DC 20590- 0001.
FOR FURTHER INFORMATION CONTACT: Stephen K. Sheely, Aerospace Engineer,
Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New
England Executive Park, Burlington, MA 01803; e-mail: stephen.k.sheely@faa.gov;
telephone (781) 238-7750; fax (781) 238-7199.
SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR part
39 with a proposed AD. The proposed AD applies to CFM International S.A.
CFM56-2, CFM56-3, CFM56-5A, CFM56-5B, CFM56-5C, and CFM56-7B series turbofan
engines with certain P/N and SN HPC 4-9 spools installed. We published
the proposed AD in the Federal Register on November 26, 2008 (73 FR 71951).
That action proposed to require removing certain HPC 4-9 spools that have
a P/N and SN listed in Table 1 of this AD before accumulating 8,900 cycles
since repair at PTLLC or within 1,100 cycles from the effective date of
this AD, whichever occurs later.
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 regulatory evaluation, 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.
Incorrect SN in Table 1 of the Proposed AD
Three commenters, the Air Transport Association (ATA), United Airlines,
and CFM International, point out a typographical error in the SN for a
4-9 spool, P/N 1590M29G01. They state that the Special Airworthiness Information
Bulletin (SAIB) NE-08-17 shows SN GWNFY924 for that P/N and the proposed
rule shows SN GWNFY824 for the same P/N.
We agree. Serial number GWNFY924 is the correct SN. We changed Table 1,
P/N 1590M29G01 SN ``GWNFY824,'' to ``GWNFY924'' in this AD.
Request To Clarify the Relationship Between SAIB NE-08-17 and the Proposed
AD
One commenter, the ATA, suggests the proposed AD doesn't show a clear
relationship between its requirements and those contained in SAIB NE-08-17.
The ATA suggests we provide a clarification and a better understanding
of why we wrote SAIB NE-08-17 and the proposed rule. The ATA also asks
if the recommendations or the hardware listed in SAIB NE- 08-17 is still
in effect.
We partially agree. The proposed AD specifies the same twenty-six 4-9
spools as SAIB NE-08-17. Special Airworthiness Information Bulletin NE-08-17
still provides recommendations for dispositioning other parts listed in
that SAIB. However, we don't require removing the hardware listed in SAIB
NE-08-17, other than the 4-9 spools. We didn't change the AD.
Request To Delete ``Seal Tooth Plasma Overspray'' Statement From Discussion
One commenter, CFM International, asks us to delete ``Seal tooth plasma
overspray between the seal teeth, which is not permitted by the engine
overhaul manual, and'' from the Discussion Section. CFM International
states that the overhaul manual does allow plasma overspray between the
seal teeth.
We agree that the overhaul manual allows plasma overspray between the
seal teeth. However, the Discussion Section is not included in the AD.
We didn't change the AD.
Request To Include Instructions for Dispositioning the Removed 4-9
Spool
One commenter, Japan Airlines, states that we include a prohibition for
installing the affected 4-9 spools, but we don't specify what to do with
the 4-9 spools removed as specified in the proposed AD. They ask us to
provide instructions to disposition the removed 4-9 spools.
We don't agree. The proposed rule requires removing from service, certain
4-9 spools, which removes the unsafe condition. The included installation
prohibition resolves our remaining regulatory concerns. How operators
recycle metal is beyond the scope of an AD, so long as the excluded part
doesn't find its way back into service. We didn't change the AD.
Request To Clarify the Compliance Times
One commenter, the Boeing Company, asks us to clarify the compliance times
for removing the affected 4-9 spools. Boeing suggests that, as written,
the compliance times of ``before accumulating 8,900 cycles-since-repair
at PTLLC or within 1,100 cycles after the effective date of this AD,''
could allow up to 10,000 cycles to accumulate on an engine before an operator
has to take corrective action.
We agree. That is what we intended. We didn't change the AD.
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 26 engines installed on airplanes
of U.S. registry. We also estimate that it will take about 410 work-hours
per engine to perform the required actions, and that the average labor
rate is $80 per work-hour. Required parts will cost about $227,500 per
engine. Based on these figures, we estimate the total cost of the AD to
U.S. operators to be $6,767,800.
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 39
Air transportation, Aircraft, Aviation safety, 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 adding the following new airworthiness
directive:
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