80 FR 55235 - Airworthiness Directives; CFM International S.A. Turbofan Engines

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 80, Issue 178 (September 15, 2015)

We are adopting a new airworthiness directive (AD) for certain CFM International S.A. (CFM) CFM56-7B and CFM56-3 turbofan engines. This AD was prompted by a report of an uncommanded in-flight shutdown (IFSD) on a CFM CFM56-7B engine following rupture of the 73-tooth gearshaft located in the engine accessory gearbox (AGB). This AD requires AGB/transfer gearbox (TGB) magnetic chip detector (MCD) inspection of the affected gearshafts until removal. We are issuing this AD to prevent failure of certain engine AGB gearshafts, which could lead to failure of one or more engines, loss of thrust control, and damage to the airplane.

[Federal Register Volume 80, Number 178 (Tuesday, September 15, 2015)]
[Rules and Regulations]
[Pages 55235-55237]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2015-22598]



[[Page 55235]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2015-0277; Directorate Identifier 2015-NE-05-AD; 
Amendment 39-18262; AD 2015-18-04]
RIN 2120-AA64


Airworthiness Directives; CFM International S.A. Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for certain 
CFM International S.A. (CFM) CFM56-7B and CFM56-3 turbofan engines. 
This AD was prompted by a report of an uncommanded in-flight shutdown 
(IFSD) on a CFM CFM56-7B engine following rupture of the 73-tooth 
gearshaft located in the engine accessory gearbox (AGB). This AD 
requires AGB/transfer gearbox (TGB) magnetic chip detector (MCD) 
inspection of the affected gearshafts until removal. We are issuing 
this AD to prevent failure of certain engine AGB gearshafts, which 
could lead to failure of one or more engines, loss of thrust control, 
and damage to the airplane.

DATES: This AD is effective October 20, 2015.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of October 20, 
2015.

ADDRESSES: For service information identified in this AD, contact CFM 
International Inc., Aviation Operations Center, 1 Neumann Way, M/D Room 
285, Cincinnati, OH 45125; phone: 877-432-3272; fax: 877-432-3329; 
email: [email protected]. You may view this service 
information at the FAA, Engine & Propeller Directorate, 12 New England 
Executive Park, Burlington, MA. For information on the availability of 
this material at the FAA, call 781-238-7125. It is also available on 
the Internet at http://www.regulations.gov by searching for and 
locating Docket No. FAA-2015-0277.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2015-
0277; or in person at the Docket Management Facility 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 address for the Docket Office (phone: 800-647-
5527) is Document Management Facility, U.S. Department of 
Transportation, Docket Operations, M-30, West Building Ground Floor, 
Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Kyle Gustafson, Aerospace Engineer, 
Engine Certification Office, FAA, Engine & Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803; phone: 781-238-7183; 
fax: 781-238-7199; email: [email protected].

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 by adding an AD that would apply to certain CFM CFM56-7B series 
turbofan engines. The NPRM published in the Federal Register on May 1, 
2015 (80 FR 24856). The NPRM was prompted by a report of an uncommanded 
IFSD on a CFM CFM56-7B engine following rupture of the 73-tooth 
gearshaft located in the engine AGB. The NPRM proposed to require MCD 
inspection of the affected gearshafts until removal.

Comments

    We gave the public the opportunity to participate in developing 
this AD. The following presents the comments received on the NPRM (80 
FR 24856, May 1, 2015) and the FAA's response to each comment.

Request To Add CFM56-3 Engines to Applicability

    CFM requested that we add CFM56-3 engines to this AD, as the CFM56-
3 engines share the same 73-tooth and 41-tooth gearshafts as the CFM56-
7B engines.
    We agree. We revised the applicability of this AD by adding CFM56-3 
engines.

Request To Clarify Discussion of IFSDs

    CFM commented that the NPRM (80 FR 24856, May 1, 2015) incorrectly 
indicated that multiple instances of uncommanded IFSDs occurred on 
CFM56-7B engines following rupture of the 73-tooth gearshaft when only 
one IFSD actually occurred. CFM requested that this AD be revised to 
reflect that only one IFSD occurred following rupture of the 73-tooth 
gearshaft.
    We agree. We revised the Summary, Discussion, and Unsafe Condition 
sections of this final rule to reflect the occurrence of one IFSD 
following rupture of the 73-tooth gearshaft in the CFM56-7B's AGB.

Request To Clarify Inspection Requirement

    CFM commented that the NPRM (80 FR 24856, May 1, 2015) did not 
clearly specify that the MCD inspection is of the AGB/TGB.
    We agree. We revised the Summary and the Compliance sections of 
this final rule to reflect that the required inspection is an ``AGB/TGB 
MCD inspection.''

Request To Clarify Relevant Service Information

    CFM requested that we specify in the Relevant Service Information 
section of the NPRM (80 FR 24856, May 1, 2015) that the referenced 
service bulletins (SBs) describe the procedures for removal of the 
affected 73-tooth and 41-tooth gearshafts and also list the affected 
gearshafts by serial number (S/N).
    We disagree. This AD does not include a ``Relevant Service 
Information'' section. We are, however, incorporating this SB by 
reference and it is available on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2015-
0277. We did not change this AD.

Request To Clarify Proposed AD Requirements

    CFM commented that the Proposed AD Requirements section should be 
revised to be consistent with the compliance and mandatory terminating 
action paragraphs in this AD.
    We disagree. This AD incorporates changes produced as a result of 
the comments received, as permitted by the Administrative Procedures 
Act (APA) (Pub. L. 79-404, 5 U.S.C. 551, et. seq.). To take the action 
the commenter suggests would be contrary to the APA. We did not change 
this AD.

Request To Allow Use of Later Revisions to SBs

    CFM requested that we include a provision in this AD to allow for 
use of later revisions to CFM SB No. CFM56-7B S/B 72-0964, Revision 1, 
dated December 15, 2014, and SB No. CFM56-7B S/B 72-0965, dated 
December 16, 2014.
    We disagree. We do not know the content of future revisions of SBs 
and, therefore, cannot approve them before publication. We did not 
change this AD.

Request To Revise Description of Laboratory Analysis

    CFM requested we change the wording in the Compliance section of 
this AD from ``particles lab analysis'' to ``laboratory analysis.''

[[Page 55236]]

    We agree. The term ``laboratory analysis'' is more accurate. We 
revised the term ``particles lab analysis'' to read ``laboratory 
analysis'' in the Compliance section of this AD.

Request To Include Serial Numbers of Affected Gearshafts

    CFM requested that we include the S/Ns of the affected 73-tooth and 
41-tooth gearshafts in this AD instead of referencing the SBs. CFM 
indicated that CFM56-3 operators may not have access to the CFM56-7B 
SBs.
    We disagree. Operators have access to CFM SB No. CFM56-7B S/B 72-
0964, Revision 1, dated December 15, 2014, in the AD docket on the 
Internet at http://www.regulations.gov by searching for and locating 
Docket No. FAA-2015-0277, or by requesting the SB from CFM. We did not 
change this AD.

Request To Limit Applicability by Engine Serial Number

    Sun Country Airlines requested that the Applicability of this AD be 
limited to CFM56-7B engines with engine S/Ns listed in Appendix A of 
CFM SB No. CFM56-7B S/B 72-0964 and CFM56-7B engines that have the 73-
tooth gearshafts listed in Appendix B of CFM SB No. CFM56-7B S/B 72-
0964 installed post-production. Sun Country Airlines noted that the 
applicability of the NPRM (80 FR 24856, May 1, 2015) could be 
misconstrued to mean to include all CFM56-7B engines unless it is 
proven that they do not have the affected 73-tooth or 41-toth 
gearshafts.
    We disagree. CFM identified the affected population of gearshafts 
by gearshaft S/N and by the engine S/N on which it was installed. 
However, an affected gearshaft may now be installed on an engine with 
an S/N not listed in Appendix A. To address the latter population, 
those engines with a gearshaft that has been installed on an unknown 
engine, we identified the affected population of 73-tooth and 41-tooth 
gearshafts by gearshaft part number and S/N. We did not change this AD.

Request To Clarify That Applicability Is by Gearshaft Serial Number

    Delta Air Lines (Delta) requested that we clarify that the 
applicability of the AD is by gearshaft S/N rather than by engine S/N.
    We agree. We revised the Applicability paragraph of this AD to 
read: ``This AD applies to all CFM International S.A. (CFM) CFM56-7B 
and CFM56-3 engines with a 73-tooth or 41-tooth gearshaft installed in 
the accessory gearbox (AGB), that has a gearshaft serial number in 
Appendix A or Appendix B of CFM Service Bulletin (SB) No. CFM56-7B S/B 
72-0964, Revision 1, dated December 15, 2014.''

Request To Verify Affected Gearshafts Have Been Removed From Service 
and Reduce the Scope of Applicability

    Delta requested that we verify which gearshafts have been removed 
from service per the proposed requirements of the NPRM (80 FR 24856, 
May 1, 2015). Delta further asked that we reduce the applicability to 
only those affected gearshafts that remain in service.
    We disagree. This AD will ensure that all affected gearshafts are 
removed from service and that gearshafts already removed from service 
are not returned to service. We did not change this AD.

Support for the NPRM

    The Boeing Company and an anonymous commenter expressed support for 
the NPRM (80 FR 24856, May 1, 2015) as proposed.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
this AD with the changes described previously.
    We also determined that these changes will not increase the 
economic burden on any operator or increase the scope of this AD.

Related Service Information Under 1 CFR Part 51

    We reviewed CFM SB No. CFM56-7B S/B 72-0964, Revision 1, dated 
December 15, 2014. The service information describes procedures for 
removal of affected 73-tooth and 41-tooth gearshafts. This service 
information is reasonably available because the interested parties have 
access to it through their normal course of business or by the means 
identified in the ADDRESSES section of this AD.

Costs of Compliance

    We estimate that this AD will affect about 67 engines installed on 
airplanes of U.S. registry. We also estimate that it will take about 1 
hour per engine to do the inspection and 8 hours per engine to replace 
each affected gearshaft. We estimate thirty-six 73-tooth gearshafts and 
forty 41-tooth gearshafts will need replacement at a cost of $12,480 
and $7,680 per part, respectively. The average labor rate is $85 per 
hour. Based on these figures, we estimate the cost of this AD on U.S. 
operators to be $813,855.

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

    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),
    (3) Will not affect intrastate aviation in Alaska to the extent 
that it justifies making a regulatory distinction, 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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.


[[Page 55237]]




Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

2015-18-04 CFM International S.A.: Amendment 39-18262; Docket No. 
FAA-2015-0277; Directorate Identifier 2015-NE-05-AD.

(a) Effective Date

    This AD is effective October 20, 2015.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to CFM International S.A. (CFM) CFM56-7B and 
CFM56-3 engines with a 73-tooth or 41-tooth gearshaft installed in 
the accessory gearbox (AGB), that has a gearshaft serial number in 
Appendix A or Appendix B of CFM Service Bulletin (SB) No. CFM56-7B 
S/B 72-0964, Revision 1, dated December 15, 2014.

(d) Unsafe Condition

    This AD was prompted by a report of an uncommanded in-flight 
shutdown on a CFM CFM56-7B engine following rupture of the 73-tooth 
gearshaft located in the engine AGB. We are issuing this AD to 
prevent failure of certain AGB gearshafts, which could lead to 
failure of one or more engines, loss of thrust control, and damage 
to the airplane.

(e) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(1) Initial AGB/Transfer Gearbox (TGB)/Magnetic Chip Detector (MCD) 
Inspection and Analysis

    (i) For affected 73-tooth gearshafts, perform an AGB/TGB MCD 
inspection within 250 flight hours (FHs) since last inspection, 
within 25 FHs from the effective date of this AD, or when the 
gearshaft accumulates 3,000 FHs since new, whichever comes later.
    (ii) For affected 41-tooth gearshafts, perform an AGB/TGB MCD 
inspection within 250 FHs since last inspection, within 25 FHs from 
the effective date of this AD, or when the gearshaft accumulates 
6,000 FHs since new, whichever comes later.
    (iii) If any magnetic particles, including fuzz, are seen, 
determine with laboratory analysis if the particles are 73-tooth or 
41-tooth gearshaft material.
    (iv) If the particles are 73-tooth or 41-tooth gearshaft 
material, remove the affected gearshaft(s) within 75 FHs since the 
AGB/TGB MCD inspection.

(2) Repetitive AGB/TGB MCD Inspection and Analysis

    (i) For affected 73-tooth gearshafts, perform an AGB/TGB MCD 
inspection and laboratory analysis within every 500 FHs since the 
last AGB/TGB MCD inspection until affected gearshaft is removed.
    (ii) For affected 41-tooth gearshafts, perform an AGB/TGB MCD 
inspection and laboratory analysis within every 500 FHs since the 
last AGB/TGB MCD inspection until affected gearshaft is removed.
    (iii) If any magnetic particles, including fuzz, are seen, 
determine with laboratory analysis if the particles are 73-tooth or 
41-tooth gearshaft material.
    (iv) If the particles are 73-tooth or 41-tooth gearshaft 
material, remove the affected gearshaft(s) within 75 FHs since the 
AGB/TGB MCD inspection.

(f) Mandatory Terminating Action

    (1) Remove the affected 73-tooth gearshaft prior to the 
gearshaft accumulating 6,000 FHs since new or within 50 FHs after 
the effective date of this AD, whichever comes later.
    (2) Remove the affected 41-tooth gearshaft prior to the 
gearshaft accumulating 9,000 FHs since new or within 50 FHs after 
the effective date of this AD, whichever comes later.

(g) Installation Prohibition

    After the effective date of this AD, do not install an affected 
gearshaft into an AGB.

(h) Alternative Methods of Compliance (AMOCs)

    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. You may email your request to: [email protected].

(i) Related Information

    For more information about this AD, contact Kyle Gustafson, 
Aerospace Engineer, Engine Certification Office, FAA, Engine & 
Propeller Directorate, 12 New England Executive Park, Burlington, MA 
01803; phone: 781-238-7183; fax: 781-238-7199; email: 
[email protected].

(j) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (3) The following service information was approved for IBR on 
October 20, 2015.
    (i) CFM International Service Bulletin No. CFM56-7B S/B 72-0964, 
Revision 1, dated December 15, 2014.
    (ii) Reserved.
    (4) For CFM service information identified in this AD, contact 
CFM International Inc., Aviation Operations Center, 1 Neumann Way, 
M/D Room 285, Cincinnati, OH 45125; phone: 877-432-3272; fax: 877-
432-3329; email: [email protected].
    (5) You may view this service information at FAA, Engine & 
Propeller Directorate, 12 New England Executive Park, Burlington, 
MA. For information on the availability of this material at the FAA, 
call 781-238-7125.
    (6) You may view this service information at the National 
Archives and Records Administration (NARA). For information on the 
availability of this material at NARA, call 202-741-6030, or go to: 
http://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Burlington, Massachusetts, on August 28, 2015.
Ann C. Mollica,
Acting Directorate Manager, Engine & Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2015-22598 Filed 9-14-15; 8:45 am]
BILLING CODE 4910-13-P