### 43925 Federal Register / Vol. 80, No. 142 / Friday, July 24, 2015 / Rules and Regulations

(3) Where Boeing Alert Service Bulletin 737–53A1108, Revision 7, dated July 7, 2014, specifies accomplishment of a preventative modification in accordance with ‘‘Revision 6 of this service bulletin,’’ this AD requires accomplishment of those actions to be done in accordance with Boeing Alert Service Bulletin 737–53A1108, Revision 7, dated July
7, 2014.

(4) Where table 4 in paragraph 1.E, ‘‘Compliance,’’ of Boeing Alert Service Bulletin 737–53A1108, Revision 7, dated July 7, 2014, specifies repairing a condition identified as any crack found in ‘‘an intercostal,’’ this AD requires repairing a condition identified as any crack found in ‘‘an intercostal or attaching stringers.’’

(l) Credit for Previous Actions

This paragraph provides credit for the actions required by paragraphs (g) and (h) of this AD, if those actions were performed before the effective date of this AD using Boeing Alert Service Bulletin 737–53A1108, Revision 6, dated January 9, 2014. This service information is not incorporated by reference in this AD.

(m) Alternative Methods of Compliance (AMOCs)

(1) The Manager, Los Angeles Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the manager of the ACO, send it to the attention of the person identified in paragraph (n)(1) of this AD. Information may be emailed to: 9-ANM-LAACO-ACO-AMOCRequests@faa.gov.

(2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/ certificate holding district office.

(3) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD if it is approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) that has been authorized by the Manager, Los Angeles ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane, and the approval must specifically refer to this AD.

(4) AMOCs approved previously for AD 98–22–10, Amendment 39–10858 (63 FR 57240, October 27, 1998), are approved as AMOCs for the corresponding provisions of this AD.

(5) Accomplishment of the preventive modification in accordance with Boeing Alert Service Bulletin 737–53A1108, Revision 7, dated July 7, 2014, as required by paragraph (h) of this AD, is an AMOC for the structural modification specified in Boeing Alert Service Bulletin 737–53A1108 that is required by paragraph A. of AD 90–06–02, Amendment 39–6489, (55 FR 8372, March 7, 1990), for the airplanes identified in paragraph (h) of this AD. (n) Related Information
(1) For more information about this AD, contact Nenita Odesa, Aerospace Engineer, Airframe Branch, ANM–120L, FAA, Los Angeles ACO, 3960 Paramount Boulevard, Lakewood, CA 90712–4137; phone: 562–627– 5234; fax: 562–627–5210; email: nenita.odesa@faa.gov.

(2) Service information identified in this AD that is not incorporated by reference is available at the addresses specified in paragraph (o)(3) of this AD.
(o) 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.

(i) Boeing Alert Service Bulletin 737– 53A1108, Revision 7, dated July 7, 2014. (ii) Reserved.

(3) For Boeing service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H–65, Seattle, WA 98124–2207; phone: 206–544–5000, extension 1; fax: 206–766– 5680; Internet https:// www.myboeingfleet.com.

(4) You may view this service information at FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, WA. For information on the availability of this material at the FAA, call 425–227–1221.

(5) You may view this service information that is incorporated by reference 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/ibrlocations.html.

Issued in Renton, Washington, on July 10,

2015. Jeffrey E. Duven, Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 2015–17977 Filed 7–23–15; 8:45 am]

**BILLING CODE 4910–13–P**

**DEPARTMENT OF TRANSPORTATION**

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2015–0679; Directorate Identifier 2013–NM–182–AD; Amendment**  **39–18211; AD 2015–15–02]**

**RIN 2120–AA64**

**Airworthiness Directives; Airbus Airplanes** 

**AGENCY :**  Federal Aviation Administration (FAA), Department of Transportation (DOT).

**ACTION :**  Final rule. **SUMMARY :**  We are superseding Airworthiness Directive (AD) 2012–13– 06, for all Airbus Model A300 series airplanes and all Model A300 B4–600, B4–600R, and F4–600R series airplanes, and Model A300 C4–605R Variant F airplanes (collectively called Model A300–600 series airplanes). AD 2012– 13–06 required a one-time detailed inspection to determine the length of the fire shut-off valve (FSOV) bonding leads and for contact or chafing of the wires, and corrective actions if necessary. This new AD requires a new one-time detailed inspection of the FSOV bonding leads to ensure that the correct bonding leads are inspected, and corrective action if necessary. This AD was prompted by a determination that the description of the inspection area specified in the service information was misleading; therefore, some operators might have inspected incorrect bonding leads. We are issuing this AD to detect and correct contact or chafing of wires and the bonding leads, which, if not detected, could be a source of sparks in the wing trailing edge, and could lead to an uncontrolled engine fire.

**DATES :**  This AD becomes effective August 28, 2015.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of August 28, 2015.

**ADDRESSES :**  You may examine the AD docket on the Internet at http:// www.regulations.gov/ #!docketDetail;D=FAA-2015-0679; or in person at the Docket 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.

For service information identified in this AD, contact Airbus SAS, Airworthiness Office—EAW, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone +33 5 61 93 36 96; fax +33 5 61 93 44 51; email account.airworth-eas@airbus.com;
Internet http://www.airbus.com. You may view this referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, WA. For information on the availability of this material at the FAA, call 425–227–1221. It is also available on the Internet at http:// www.regulations.gov by searching for and locating Docket No. FAA–2015–

0679.

**FOR FURTHER INFORMATION CONTACT :**  Dan Rodina, Aerospace Engineer, International Branch, ANM–116, Transport Airplane Directorate, FAA, 1601 Lind Avenue SW., Renton, WA


### 43926 Federal Register / Vol. 80, No. 142 / Friday, July 24, 2015 / Rules and Regulations

98057–3356; telephone 425–227–2125; fax 425–227–1149.

**SUPPLEMENTARY INFORMATION :** 

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2012–13–06, Amendment 39–17108 (77 FR 40485, July 10, 2012). AD 2012–13–06 applied to all Airbus Model A300 series airplanes and all Model A300 B4–600, B4–600R, and F4–600R series airplanes, and Model A300 C4–605R Variant F airplanes (collectively called Model A300–600 series airplanes). The NPRM published in the Federal Register on March 31, 2015 (80 FR 17003). The NPRM was prompted by a determination that the description of the inspection area specified in the service information was misleading; therefore, some operators might have inspected incorrect bonding leads. The NPRM proposed to require a new one-time detailed inspection of the FSOV bonding leads to ensure that the correct bonding leads are inspected, and corrective action if necessary. We are issuing this AD to detect and correct contact or chafing of wires and the bonding leads, which, if not detected, could be a source of sparks in the wing trailing edge, and could lead to an uncontrolled engine fire.

The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union, has issued EASA Airworthiness Directive 2013–0204, dated September 6, 2013 (referred to after this as the Mandatory Continuing Airworthiness Information, or ‘‘the MCAI’’), to correct an unsafe condition. The MCAI states:

During a scheduled maintenance check, one operator reported inoperative Fire Shut Off Valve (FSOV). Investigations showed damage at wire located between engine 2 hydraulic FSOV and wing rear spar, in the zones 575/675, and at bonding lead, located between wing rib 7A and rib 8 below hydraulic pressure lines.

Similar inspections on different aeroplanes have shown that one of the causes of damage is the contact between bonding lead and the harness, due to over length of the bonding lead.

This condition, if not detected and corrected, could lead to either: —A potential explosive condition on-ground

if the FSOV, that is installed in fuel vapor zone is commanded to close position, or —a temporary uncontrolled engine fire, if

combined with a fire event in the nacelle fed by an hydraulic leakage and not controlled by the fire extinguishing system. As the affected wire is not powered during normal operation, no defect can be detected unless a test is performed on the FSOV during maintenance check. EASA issued AD 2011–0084 [ http:// ad.easa.europa.eu/blob/easa

_ ad

_2011

_ 0084.pdf/AD

_2011-0084

_ Superseded] which required a one-time [detailed] inspection of the wires [for contact or chafing] located between [LH/RH] engines hydraulic FSOV and wing rear spar in the zones 575/675, and the bonding lead [for length] that is located between rib 7A and rib 8 below hydraulic pressure lines, and corrective actions [repair of wires or replacement of bonding leads] depending on findings.

It appeared that the original issue of the Airbus inspection Service Bulletins (SB’s) as well as EASA AD 2011–0084 might have caused possible misunderstandings on the exact bonding leads and wires that are required to be inspected.

For the reasons described above, this [EASA] AD retains the requirements of EASA AD 2011–0084, which is superseded, and requires additional work on aeroplanes that have already been inspected in accordance with the instructions of the original issue of the SB’s.
You may examine the MCAI in the AD docket on the Internet at http:// www.regulations.gov/ #!documentDetail;D=FAA-2015-0679-

0002.

Comments

We gave the public the opportunity to participate in developing this AD. We received no comments on the NPRM (80 FR 17003, March 31, 2015) or on the determination of the cost to the public.

Conclusion

We reviewed the relevant data and determined that air safety and the public interest require adopting this AD as proposed except for minor editorial changes. We have determined that these minor changes:

• Are consistent with the intent that was proposed in the NPRM (80 FR 17003, March 31, 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 17003, March 31, 2015).

Related Service Information Under 1
CFR Part 51

Airbus has issued Service Bulletin A300–24–0106, Revision 01, dated March 26, 2013 (for Model A300 series airplanes); and Service Bulletin A300– 24–6108, Revision 01, dated March 26, 2013 (for Model A300–600 series airplanes). The service information describes procedures for inspecting the FSOV bonding leads, corrective actions, and repair of the associated wires. 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 affects 123 airplanes of U.S. registry.

We estimate that it takes about 8 work-hours per product to comply with the basic requirements of this AD. The average labor rate is $85 per work-hour. Required parts cost about $500 per product. Based on these figures, we estimate the cost of this AD on U.S. operators to be $145,140, or $1,180 per product.

In addition, we estimate that any necessary follow-on actions take about 1 work-hour and require parts costing $50, for a cost of $135 per product. We have no way of determining the number of products that may need these actions.
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


### 43927 Federal Register / Vol. 80, No. 142 / Friday, July 24, 2015 / Rules and Regulations

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-2015-0679; 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 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** 

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

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

**§ 39.13 [Amended]**

■ 2. The FAA amends § 39.13 by removing Airworthiness Directive (AD) 2012–13–06, Amendment 39–17108 (77 FR 40485, July 10, 2012), and adding the following new AD:

2015–15–02 Airbus: Amendment 39–18211. Docket No. FAA–2015–0679; Directorate Identifier 2013–NM–182–AD.

(a) Effective Date

This AD becomes effective August 28,

2015.

(b) Affected ADs

This AD replaces AD 2012–13–06, Amendment 39–17108 (77 FR 40485, July 10, 2012).

(c) Applicability

This AD applies to the airplanes specified in paragraphs (c)(1), (c)(2), and (c)(3) of this AD, certificated in any category, all manufacturer serial numbers.

(1) Airbus Model A300 B2–1A, B2–1C, B2K–3C, B2–203, B4–2C, B4–103, and B4– 203 airplanes.

(2) Airbus Model A300 B4–601, B4–603, B4–620, B4–622, B4–605R, B4–622R, F4– 605R, and F4–622R airplanes.

(3) Airbus Model A300 C4–605R Variant F airplanes. (d) Subject Air Transport Association (ATA) of America Code 24, Electrical Power.

(e) Reason

This AD was prompted by a determination that the description of the inspection area specified in the service information was misleading; therefore, some operators might have inspected incorrect bonding leads. We are issuing this AD to detect and correct contact or chafing of wires and the bonding leads, which, if not detected, could be a source of sparks in the wing trailing edge, and could lead to an uncontrolled engine fire.
(f) Compliance

Comply with this AD within the compliance times specified, unless already done.
(g) Inspection of the Fire Shut-Off Valve (FSOV) Bonding Leads

At the applicable time specified inparagraph (g)(1) or (g)(2) of this AD: Do a onetime detailed inspection to determine the length of the FSOV bonding leads, and to detect contact or chafing of the wires located on the left-hand (LH) and right-hand (RH) sides of the wing rear spar, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A300–24–0106, Revision 01, dated March 26, 2013 (for Model A300 series airplanes); or Airbus Service Bulletin A300–24–6108, Revision 01, dated March 26, 2013 (for Model A300–600 series airplanes); as applicable.

(1) For airplanes on which the inspection required by paragraph (g) of AD 2012–13–06, Amendment 39–17108 (77 FR 40485, July 10, 2012), has not been done as of the effective date of this AD: Inspect within 4,500 flight hours or 30 months after August 14, 2012 (the effective date of AD 2012–13–06), whichever occurs first.

(2) For airplanes on which the inspection required by paragraph (g) of AD 2012–13–06, Amendment 39–17108 (77 FR 40485, July 10, 2012), has been done as of the effective date of this AD: Inspect within 4,500 flight hours or 30 months after the effective date of this AD, whichever occurs first.
(h) Corrective Action for FSOV Bonding Leads

If, during the inspection required by paragraph (g) of this AD, the length of the bonding lead(s) is more than 80 millimeters (mm) (3.15 inches): Before further flight, replace the bonding lead(s) with a new bonding lead having a length equal to 80 mm

± 2 mm (3.15 inches) ± 0.08 inch, in accordance with the Accomplishment Instructions of the applicable service information identified in paragraph (g) of this
AD.
(i) Repair of the Wires of the LH and RH Sides

If, during the inspection required by paragraph (g) of this AD, any contact or chafing of the wires is found, repair the wires before further flight, in accordance with the Accomplishment Instructions of the applicable service information identified in paragraph (g) of this AD. (j) Parts Installation Prohibition As of August 14, 2012 (the effective date of AD 2012–13–06, Amendment 39–17108 (77 FR 40485, July 10, 2012), no person may install any bonding lead longer than 80 mm

± 2 mm (3.15 inches) ± 0.08 inch, located between the LH/RH engine hydraulic FSOV and wing rear spar in zones 575/675 on any airplane.

(k) Other FAA AD Provisions

The following provisions also apply to this
AD:

(1) Alternative Methods of Compliance (AMOCs): The Manager, International Branch, ANM–116, Transport Airplane Directorate, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the International Branch, send it to ATTN: Dan Rodina, Aerospace Engineer, International Branch, ANM–116, Transport Airplane Directorate, FAA, 1601 Lind Avenue SW., Renton, WA 98057–3356; telephone 425–227–2125; fax 425–227–1149. Information may be emailed to: 9-ANM-116- AMOC-REQUESTS@faa.gov. Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office. The AMOC approval letter must specifically reference this AD.

(2) Contacting the Manufacturer: As of the effective date of this AD, for any requirement in this AD to obtain corrective actions from a manufacturer, the action must be accomplished using a method approved by the Manager, International Branch, ANM– 116, Transport Airplane Directorate, FAA; or the European Aviation Safety Agency (EASA); or Airbus’s EASA Design Organization Approval (DOA). If approved by the DOA, the approval must include the DOA-authorized signature.

(l) Related Information

Refer to Mandatory Continuing Airworthiness Information (MCAI) EASA Airworthiness Directive 2013–0204, dated September 6, 2013, for related information. This MCAI may be found in the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No.
FAA–2015–0679.
(m) 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 this AD specifies otherwise.

(3) The following service information was approved for IBR on August 28, 2015.

(i) Airbus Service Bulletin A300–24–0106, Revision 01, dated March 26, 2013.

(ii) Airbus Service Bulletin A300–24–6108, Revision 01, dated March 26, 2013.

(4) For service information identified in this AD, contact Airbus SAS, Airworthiness


### 43928 Federal Register / Vol. 80, No. 142 / Friday, July 24, 2015 / Rules and Regulations

Office—EAW, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone +33 5 61 93 36 96; fax +33 5 61 93 44 51; email account.airworth-eas@ airbus.com; Internet http://www.airbus.com.

(5) You may view this service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, WA. For information on the availability of this material at the FAA, call 425–227–1221.

(6) You may view this service information that is incorporated by reference 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/ibrlocations.html.

Issued in Renton, Washington, on July 10,

2015. Michael Kaszycki, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 2015–17935 Filed 7–23–15; 8:45 am]

**BILLING CODE 4910–13–P**

**DEPARTMENT OF TRANSPORTATION**

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2014–0748; Directorate Identifier 2014–NM–013–AD; Amendment**  **39–18219; AD 2015–15–10]**

**RIN 2120–AA64**

**Airworthiness Directives; Airbus Airplanes** 

**AGENCY :**  Federal Aviation Administration (FAA), Department of Transportation (DOT).

**ACTION :**  Final rule.

**SUMMARY :**  We are adopting a new airworthiness directive (AD) for all Airbus Model A318, A319, A320, and A321 series airplanes. This AD was prompted by reports of wear of the trimmable horizontal stabilizer actuator (THSA). This AD requires repetitive inspections of the THSA for damage, and replacement if necessary; and replacement of the THSA after reaching a certain life limit. We are issuing this AD to detect and correct wear on the THSA, which would reduce the remaining life of the THSA, possibly resulting in premature failure and consequent reduced control of the airplane.

**DATES :**  This AD becomes effective August 28, 2015.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of August 28, 2015.

**ADDRESSES :**  You may examine the AD docket on the Internet at http:// www.regulations.gov/ #!docketDetail;D=FAA-2014-0748 or in person at the Docket 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.

For service information identified in this AD, contact Airbus, Airworthiness Office—EIAS, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone +33 5 61 93 36 96; fax +33 5 61 93 44 51; email account.airwortheas@airbus.com; Internet http:// www.airbus.com. You may view this referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, WA. For information on the availability of this material at the FAA, call 425–227– 1221. It is also available on the Internet

at http://www.regulations.gov by searching for and locating Docket No.
FAA 2014–0748.

**FOR FURTHER INFORMATION CONTACT :**  Sanjay Ralhan, Aerospace Engineer, International Branch, ANM–116, Transport Airplane Directorate, FAA, 1601 Lind Avenue SW., Renton, WA 98057–3356; telephone 425–227–1405; fax 425–227–1149.

**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 all Airbus Model A318, A319, A320, and A321 series airplanes. The NPRM published in the Federal Register on October 16, 2014 (79 FR 62072).

The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union, has issued EASA Airworthiness Directive 2014–0011R1, dated January 17, 2014 (referred to after this as the Mandatory Continuing Airworthiness Information, or ‘‘the MCAI’’), to correct an unsafe condition. The MCAI states:

In the frame of the A320 Extended Service Goal (ESG) project and the study on the Trimmable Horizontal Stabilizer Actuator (THSA), a sampling programme of in-service units has been performed and several cases of wear at different THSA levels were reported.

This condition, if not detected and corrected, would reduce the remaining life of the THSA, possibly resulting in premature failure and consequent reduced control of the aeroplane.

Prompted by these findings, Airbus issued Service Bulletin (SB) A320–27–1227 to provide THSA inspection instructions.

For the reasons described above, this [EASA] AD requires repetitive inspections of the THSA and introduces a life limit for the
THSA. This AD also requires a detailed inspection of the magnetic chip detector for metal particles, a spectrometric analysis of the oil drained from the THSA gearbox, a detailed inspection of the ballscrew and nut, and a detailed inspection of the upper and the lower attachments for damage. The corrective action is replacement of the THSA with a serviceable THSA. The compliance time for the THSA replacement ranges from before further flight to within 4 months from drainage of the oil sample.

You may examine the MCAI in the AD docket on the Internet at http:// www.regulations.gov/ #!documentDetail;D=FAA-2014-0748-

0002.

Comments

We gave the public the opportunity to participate in developing this AD. We have considered the comments received. The following presents the comments received on the NPRM (79 FR 62072, October 16, 2014) and the FAA’s response to each comment.
Requests To Extend Compliance Time

Airlines for America (A4A), on behalf of American Airlines (AAL), Delta Airlines (DAL), and United Airlines (UAL), requested that we extend the initial inspection compliance time in paragraph (g)(2) of the NPRM (79 FR 62072, October 16, 2014) from 4 months to 12 months after the effective date of the AD. A4A stated that the fleet age of multiple U.S. carriers means that a large number of airplanes will require inspection in a short period of time, likely resulting in schedule disruptions and/or cancellations.

We disagree with the commenters’ request. We base AD compliance times primarily on our assessment of safety risk. Some safety issues are more time sensitive than others. We consider the overall risk to the fleet, including the severity of the failure and the likelihood of the failure’s occurrence in development of the compliance time for the ADs. The FAA and EASA work closely with the respective manufacturers to ensure that all appropriate instructions and parts are available at the appropriate time to meet our collective safety goals, and that those goals are based on safety of the fleet. We have not changed this AD in this regard.
Requests To Clarify Wording in Paragraphs (h) and (j) of the NPRM (79 FR 62072, October 16, 2014)

A4A, on behalf of UAL and JetBlue, requested that we clarify the wording of