Discussion
We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR
part 39 by adding an AD that would apply to certain Airbus Model A319-
113, A319-114, A320-211, and A320-212 airplanes. The NPRM published in
the Federal Register on June 15, 2015 (80 FR 34101). The NPRM was
prompted by a report that the aft mount pylon bolts of the CFM56-5
engines may have been installed using the
[[Page 4168]]
wrong torque values. The NPRM proposed to require identification of
engines that were installed using the wrong torque values and re-torque
of the four aft mount pylon bolts of those engines. We are issuing this
AD to detect and correct improper torque of the aft mount pylon bolts,
which, if combined with any maintenance damage, could lead to aft
engine mount failure, possibly resulting in engine detachment and
consequent reduced control of the airplane.
The European Aviation Safety Agency (EASA), which is the Technical
Agent for the Member States of the European Union, has issued EASA AD
2014-0258, dated November 28, 2014 (referred to after this as the
Mandatory Continuing Airworthiness Information, or ``the MCAI''), to
correct an unsafe condition for certain Airbus Model A319-113, A319-
114, A320-211, and A320-212 airplanes. The MCAI states:
In the Aircraft Maintenance Manual (AMM) revision dated May
2013, a wrong torque value was added in AMM task 71-00-00-400-040-
A01 ``Installation of the power plant with Engine Positioner
TWW75E''. Temporary Revisions (TR) dated March 2014 were published
by Airbus to correct the information and with AMM revision dated May
2014, Task 71-00-00-400-040-A01 was corrected to include the correct
values. Notwithstanding those actions, static and fatigue analyses
have concluded that this undertorque scenario negatively impacts the
assembly performance, reducing the aft mount capability.
This condition, if not corrected and if combined with any
maintenance damage, could lead to aft engine mount failure, possibly
resulting in engine detachment and consequent reduced control of the
aeroplane.
For the reasons described above, this [EASA] AD requires
identification of CFM56-5 engines (those listed in TCDS EASA.E.067
[http://easa.europa.eu/document-library/typecertificates/easae067])
that were installed by using the wrong torque data of AMM
instructions mentioned above and re-torque of the four aft mount
pylon bolts of those engines.
You may examine the MCAI in the AD docket on the Internet at http://www.regulations.gov/#!documentDetail;D=FAA-2015-1429-0002.
Comments
We gave the public the opportunity to participate in developing
this AD. The following presents the comment received on the NPRM (80 FR
34101, June 15, 2015) and the FAA's response to each comment.
Request to Revise Paragraph (h) of the Proposed AD (80 FR 34101, June
15, 2015)
Delta Air Lines, Inc. (DAL) requested that we revise paragraph (h)
of the proposed AD (80 FR 34101, June 15, 2015), by revising the
wording to refer to the Aircraft Maintenance Manual (AMM), dated May
2013 instead of Airbus Service Bulletin A320-71-1063, including
Appendix 01, dated August 13, 2014. DAL pointed out that paragraph (h)
of the proposed AD required engine installation in accordance with
Airbus Service Bulletin A320-71-1063, including Appendix 01, dated
August 13, 2014. DAL also mentioned that Airbus Service Bulletin A320-
71-1063, including Appendix 01, dated August 13, 2014, only has
requirements for inspection and re-torque of the aft engine mount pylon
bolts.
We agree to revise paragraph (h) of this AD because Airbus Service
Bulletin A320-71-1063, including Appendix 01, dated August 13, 2014,
does not contain installation instructions. We have revised paragraph
(h) of this AD to specify that no person may install a CFM56-5 engine,
on any airplane, unless accomplishing the actions specified inparagraph (g) of this AD.
Conclusion
We reviewed the relevant data, considered the comment received, and
determined that air safety and the public interest require adopting
this AD with the change described previously and minor editorial
changes. We have determined that these minor changes:
Are consistent with the intent that was proposed in the
NPRM (80 FR 34101, June 15, 2015) for correcting the unsafe condition;
and
Do not add any additional burden upon the public than was
already proposed in the NPRM (80 FR 34101, June 15, 2015).
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
Airbus has issued Airbus Service Bulletin A320-71-1063, including
Appendix 01, dated August 13, 2014. The service information describes
procedures to detect and correct improper torque of the aft mount pylon
bolts. This serviceinformation 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.
Costs of Compliance
We estimate that this AD affects 126 airplanes of U.S. registry.
We also estimate that it will take about 2 work-hours per product
to comply with the basic requirements of this AD. The average labor
rate is $85 per work-hour. Based on these figures, we estimate the cost
of this AD on U.S. operators to be $21,420, or $170 per product.
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 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 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.
Examining the AD Docket
You may examine the AD docket on the Internet at http://www.regulations.gov/#!docketDetail;D=FAA-2015-1429; 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
[[Page 4169]]
information. The street address for the Docket Operations office
(telephone: 800-647-5527) is in the ADDRESSES section.
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.
Sec. 39.13 [Amended]
0
2. The FAA amends Sec. 39.13 by adding the following new airworthiness
directive (AD):