### 9746 Federal Register / Vol. 81, No. 38 / Friday, February 26, 2016 / Rules and Regulations

tachometer boxes identified in paragraph (c)(1) of this AD that also have installed electrical connectors labeled as P10106, P10098, and P10108; or P11F, P13F, and
P15F.

(d) Reason

This AD was prompted by reports of uncommanded in-flight shutdowns (IFSDs). We are issuing this AD to prevent failure of the tachometer box, which could lead to failure of the engine, IFSD, and loss of control of the helicopter.
(e) Actions and Compliance

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

(1) Within 1,600 flight hours after the effective date of this AD, remove the affected tachometer box from the engine.

(2) Reserved.

(f) Credit for Previous Action

You may take credit for the action required by paragraph (e) of this AD if you performed the action before the effective date of this AD in accordance with Turbomeca S.A. Mandatory Service Bulletin 292 77 0844, Version A, dated March 4, 2015.
(g) 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: ANE–AD–AMOC@faa.gov

. (h) Related Information

(1) For more information about this AD, contact Philip Haberlen, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 1200 District Avenue, Burlington, MA 01803; phone: 781–238– 7770; fax: 781–238–7199; email: philip.haberlen@faa.gov

.

(2) Refer to MCAI European Aviation Safety Agency AD 2015–0175, dated August 24, 2015, which includes Mandatory Service Bulletin No. 292 77 0844, Version B, dated July 6, 2015, for related information. You may examine the MCAI in the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA–

2015–4070.

(3) Turbomeca S.A. Mandatory Service Bulletin No. 292 77 0844, Version B, dated July 6, 2015, which is not incorporated by reference in this AD, can be obtained from Turbomeca S.A., using the contact information in paragraph (h)(4) of this AD.

(4) For service information identified in this AD, contact Turbomeca S.A., 40220 Tarnos, France; phone: 33 (0)5 59 74 40 00; fax: 33 (0)5 59 74 45 15.

(5) You may view this service information at the FAA, Engine & Propeller Directorate, 1200 District Avenue, Burlington, MA. For information on the availability of this material at the FAA, call 781–238–7125.
(i) Material Incorporated by Reference

None. Issued in Burlington, Massachusetts, on February 16, 2016. Ann C. Mollica, Acting Manager, Engine & Propeller Directorate, Aircraft Certification Service.
[FR Doc. 2016–04028 Filed 2–25–16; 8:45 am]

**BILLING CODE 4910–13–P**

**DEPARTMENT OF TRANSPORTATION**

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2015–1280; Directorate Identifier 2014–NM–064–AD; Amendment**  **39–18404; AD 2016–04–10]**

**RIN 2120–AA64**

**Airworthiness Directives; ATR—GIE Avions de Transport Re**  ** ́ gional**  **Airplanes**

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

**ACTION :**  Final rule.

**SUMMARY :**  We are adopting a new airworthiness directive (AD) for certain ATR—GIE Avions de Transport Re

 ́ gional Model ATR42–500 airplanes, and Model ATR72–102, –202, –212, and –212A airplanes. This AD was prompted by a report of chafed wires between electrical harnesses. This AD requires inspections for wire discrepancies, and corrective actions if necessary. We are issuing this AD to detect and correct damaged wiring and incorrect installation of the wiring harness and adjacent air ducts that could lead to wire harness chafing and arcing, possibly resulting in an on-board fire.

**DATES :**  This AD becomes effective April 1, 2016.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of April 1, 2016.

**ADDRESSES :**  You may examine the AD docket on the Internet at http:// www.regulations.gov/ #!docketDetail;D=FAA-2015-1280 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 final rule, contact ATR—GIE Avions de Transport Re  ́ gional, 1, Alle  ́ e Pierre Nadot, 31712 Blagnac Cedex, France; telephone +33 (0) 5 62 21 62 21; fax +33 (0) 5 62 21 67 18; email continued.airworthiness@atr.fr; Internet http://www.aerochain.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–
1280.

**FOR FURTHER INFORMATION CONTACT :**  Tom Rodriguez, Aerospace Engineer, International Branch, ANM–116, Transport Airplane Directorate, FAA, 1601 Lind Avenue SW., Renton, WA 98057–3356; telephone 425–227–1137; 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 certain ATR—GIE Avions de Transport Re  ́ gional Model ATR42–500 airplanes, and Model ATR72–102, –202, –212, and –212A airplanes. The NPRM published in the Federal Register on May 12, 2015 (80 FR 27114) (‘‘the NPRM’’). The NPRM was prompted by a report of chafed wires between electrical harnesses. The NPRM proposed to require inspections for wire discrepancies, and corrective actions if necessary. We are issuing this AD to detect and correct damaged wiring and incorrect installation of the wiring harness and adjacent air ducts, which could lead to wire harness chafing and arcing, possibly resulting in an on-board fire.

Since the NPRM was issued, the European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union, has issued EASA Airworthiness Directive 2015–0171, dated August 20, 2015 (referred to after this as the Mandatory Continuing Airworthiness Information, or ‘‘the MCAI’’), to correct an unsafe condition for certain ATR— GIE Avions de Transport Re  ́ gional Model ATR42–500 airplanes, and Model ATR72–102, –202, –212, and –212A airplanes. The MCAI states:

An erroneous cockpit indication has been reported on an in-service aeroplane. Subsequent investigation identified chafed wiring between harnesses (2M–2S–6M) and the metallic structure of the cargo lining panel above the electronic rack 90VU shelf. The chafing was most likely the result of incorrect harness installation. In some cases, the bracket, which supports the harnesses, could be incorrectly positioned. Consequently, the wiring harnesses, and in certain configurations, the adjacent air duct, could be incorrectly routed.


### 9747 Federal Register / Vol. 81, No. 38 / Friday, February 26, 2016 / Rules and Regulations

This condition, if not detected and corrected, could lead to wiring harness chafing and arcing, possibly resulting in an on-board fire.

Prompted by this unsafe condition, EASA issued AD 2014–0052 (later revised) [ http:// www.casa.gov.au/wcmswrs/main/lib100154/ 2014–0052.pdf ] to require a one-time visual inspection of the affected area including a bracket position check and, depending on findings, accomplishment of applicable corrective actions.

Since EASA AD 2014–0052R1 [ http:// ad.easa.europa.eu/blob/easa

_ad

_2014

_ 0052

_ R1

_superseded.pdf/AD

_2014-0052R1

_ 1 ] was issued, ATR determined that more aeroplanes are potentially affected (referred as Group B aeroplanes) than originally identified. It was also determined that some aeroplanes, originally addressed by AD 2014–0052, are not affected due to their specific configuration. Taking into account these findings, ATR issued Revision 03 of Service Bulletin (SB) ATR42–92–0024 and SB ATR72–92–1032 to reflect the reidentified population of affected aeroplanes.

For the reasons described above, this [EASA] AD retains the requirements of EASA AD 2014–0052R1, which is superseded, and requires inspection, and, depending on findings, applicable corrective action(s), on the adjusted range of aeroplanes.

EASA AD 2015–0171, dated August 20, 2015, replaces EASA AD 2014– 0052R1, dated April 7, 2014, which was the referenced MCAI in the NPRM. The revised MCAI adds certain airplanes and removes others from the applicability, but does not affect any U.S.-registered airplanes. You may examine the MCAI in the AD docket on the Internet at http:// www.regulations.gov/ #!documentDetail;D=FAA-2015-1280-
0003.

Comments

We gave the public the opportunity to participate in developing this AD. We received no comments on the NPRM or on the determination of the cost to the public. Changes to This AD

Since the NPRM was issued, Avions de Transport Re  ́ gional has issued Service Bulletin ATR42–92–0024, Revision 03, dated January 21, 2015; and Service Bulletin ATR72–92–1032, Revision 03, dated January 21, 2015. No additional work is required for airplanes that have accomplished the actions specified in any previous version. We have revised paragraphs (g) and (h) of this AD to reference this revised service information. We have revised paragraph (i) of this AD to give credit for actions done before the effective date of this AD using the following service bulletins.

• Avions de Transport Re  ́ gional Service Bulletin ATR42–92–0024, Revision 01, dated January 16, 2014. • Avions de Transport Re  ́ gional Service Bulletin ATR42–92–0024, Revision 02, dated April 17, 2014.

• Avions de Transport Re  ́ gional Service Bulletin ATR72–92–1032, Revision 01, dated January 16, 2014.

• Avions de Transport Re  ́ gional Service Bulletin ATR72–92–1032, Revision 02, dated April 17, 2014.

We have also revised paragraph (c) of this AD to refer to the manufacturer serial numbers of the affected airplanes as identified in EASA AD 2015–0171, dated August 20, 2015.

Conclusion

We reviewed the relevant data and determined that air safety and the public interest require adopting this AD with the changes described previously and minor editorial changes. We have determined that these minor changes:

• Are consistent with the intent that was proposed in the NPRM for correcting the unsafe condition; and

• Do not add any additional burden upon the public than was already proposed in the NPRM.

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

ATR—GIE Avions de Transport Re

 ́ gional has issued the following service bulletins.

• Avions de Transport Re  ́ gional Service Bulletin ATR42–92–0024, Revision 03, dated January 21, 2015. The service information describes procedures for inspecting the electrical harness routing on top of the 90VU electrical rack, and modification if
necessary.

• Avions de Transport Re  ́ gional Service Bulletin ATR72–92–1032, Revision 03, dated January 21, 2015. The service information describes procedures for inspecting the electrical harness routing on top of the 90VU electrical rack, and modification if
necessary.

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. Costs of Compliance

We estimate that this AD affects 1 airplane of U.S. registry.

We also estimate that it would take about 1 work-hour 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 $85, or $85 per product. In addition, we estimate that any necessary follow-on actions would take about 3 work-hours and require parts costing $82, for a cost of $337 per product. We have no way of determining the number of aircraft that might 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 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-2015-1280; 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


### 9748 Federal Register / Vol. 81, No. 38 / Friday, February 26, 2016 / Rules and Regulations

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 adding the following new airworthiness directive (AD):

2016–04–10 ATR—GIE Avions de Transport Re  ́ gional: Amendment 39– 18404. Docket No. FAA–2015–1280; Directorate Identifier 2014–NM–064–AD.

(a) Effective Date

This AD becomes effective April 1, 2016.

(b) Affected ADs

None.
(c) Applicability

This AD applies to the ATR–GIE Avions de Transport Re  ́ gional airplanes identified in paragraphs (c)(1) and (c)(2) of this AD, certificated in any category.

(1) Model ATR42–500 airplanes, serial numbers 443 through 1006 inclusive, and 1014; except serial numbers 811, 1002, and

1005.

(2) Model ATR72–102, –202, –212, and –212A airplanes, serial numbers 475 through 969 inclusive, 971 through 988 inclusive, 1025, 1028 through 1069 inclusive, 1072, and 1089 through 1175 inclusive; except serial numbers 872, 887, 893, 956, 1042, and 1162.
(d) Subject

Air Transport Association (ATA) of America Code 92, Electrical Routing.

(e) Reason

This AD was prompted by a report of chafed wires between electrical harnesses. We are issuing this AD to detect and correct damaged wiring and incorrect installation of the wiring harness and adjacent air ducts that could lead to wire harness chafing and arcing, possibly resulting in an on-board fire.
(f) Compliance

Comply with this AD within the compliance times specified, unless already done. (g) Inspections Within 500 flight hours after the effective date of this AD, do the actions specified in paragraphs (g)(1) and (g)(2) of this AD, in accordance with the Accomplishment Instructions of Avions de Transport Re  ́ gional Service Bulletin ATR42–92–0024, Revision 03, dated January 21, 2015; and Avions de Transport Re  ́ gional Service Bulletin ATR72– 92–1032, Revision 03, dated January 21, 2015; as applicable.

(1) Do a general visual inspection for damage of the electrical wires of harnesses 2M–2S–6M.

(2) Do a general visual inspection for correct routing of electrical bundle 2M–2S– 6M, and correct routing of the air duct.

(h) Corrective Actions

(1) If, during the inspection required by paragraph (g)(1) of this AD, any damage is found on the electrical wires: Before further flight, repair the wires, in accordance with the Accomplishment Instructions of Avions de Transport Re  ́ gional Service Bulletin ATR42–92–0024, Revision 03, dated January 21, 2015; and Avions de Transport Re  ́ gional Service Bulletin ATR72–92–1032, Revision 03, dated January 21, 2015; as applicable.

(2) If, during the inspection required by paragraph (g)(2) of this AD, electrical bundle 2M–2S–6M and/or an air duct is found to be incorrectly routed: Within 500 flight hours after the effective date of this AD, do a general visual inspection for correct positioning of the bracket, in accordance with the Accomplishment Instructions of Avions de Transport Re  ́ gional Service Bulletin ATR42–92–0024, Revision 03, dated January 21, 2015; and Avions de Transport Re

 ́ gional Service Bulletin ATR72–92–1032, Revision 03, dated January 21, 2015; as applicable.

(i) If, during the inspection required by paragraph (h)(2) of this AD, the bracket is found to be correctly positioned: Within 500 flight hours after the effective date of this AD, do all applicable corrective actions, in accordance with the Accomplishment Instructions of Avions de Transport Re  ́ gional Service Bulletin ATR42–92–0024, Revision 03, dated January 21, 2015; and Avions de Transport Re  ́ gional Service Bulletin ATR72– 92–1032, Revision 03, dated January 21, 2015; as applicable.

(ii) If, during the inspection required by paragraph (h)(2) of this AD, the bracket is found to be missing or incorrectly positioned: Within 500 flight hours after the inspection required by paragraph (h)(2) of this AD, repair using a method approved by the Manager, International Branch, ANM–116, Transport Airplane Directorate, FAA; or the European Aviation Safety Agency (EASA); or ATR–GIE Avions de Transport Re  ́ gional’s EASA Design Organization Approval (DOA).

(i) Credit for Previous Actions

This paragraph provides credit for actions required by this AD, if those actions were performed before the effective date of this AD using the applicable service bulletins specified in paragraphs (i)(1) through (i)(6) of this AD, which are not incorporated by reference in this AD.

(1) Avions de Transport Re  ́ gional Service Bulletin ATR42–92–0024, dated June 6, 2013. (2) Avions de Transport Re  ́ gional Service Bulletin ATR42–92–0024, Revision 01, dated January 16, 2014.

(3) Avions de Transport Re  ́ gional Service Bulletin ATR42–92–0024, Revision 02, dated April 17, 2014.

(4) Avions de Transport Re  ́ gional Service Bulletin ATR72–92–1032, dated June 6, 2013.

(5) Avions de Transport Re  ́ gional Service Bulletin ATR72–92–1032, Revision 01, dated January 16, 2014.

(6) Avions de Transport Re  ́ gional Service Bulletin ATR72–92–1032, Revision 02, dated April 17, 2014.
(j) 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: Tom Rodriguez, Aerospace Engineer, International Branch, ANM–116, Transport Airplane Directorate, FAA, 1601 Lind Avenue SW., Renton, WA 98057–3356; telephone 425–227–1137; 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: For any requirement in this AD to obtain corrective actions from a manufacturer, the actions must be accomplished using a method approved by the Manager, International Branch, ANM–116, Transport Airplane Directorate, FAA; or the EASA; or ATR–GIE Avions de Transport Re  ́ gional’s EASA DOA. If approved by the DOA, the approval must include the DOA-authorized signature.

(k) Related Information

(1) Refer to Mandatory Continuing Airworthiness Information (MCAI) EASA Airworthiness Directive 2015–0171, dated August 20, 2015, for related information. This MCAI may be found in the AD docket on the Internet at http:// www.regulations.gov/ #!documentDetail;D=FAA-2015-1280-0003.

(2) Service information identified in this AD that is not incorporated by reference is available at the addresses specified in paragraphs (l)(3) and (l)(4) of this AD.
(l) 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.


### 9749 Federal Register / Vol. 81, No. 38 / Friday, February 26, 2016 / Rules and Regulations

(i) Avions de Transport Re  ́ gional Service Bulletin ATR42–92–0024, Revision 03, dated January 21, 2015.

(ii) Avions de Transport Re  ́ gional Service Bulletin ATR72–92–1032, Revision 03, dated January 21, 2015.

(3) For service information identified in this AD, contact ATR–GIE Avions de Transport Re  ́ gional, 1, Alle  ́ e Pierre Nadot, 31712 Blagnac Cedex, France; telephone +33 (0) 5 62 21 62 21; fax +33 (0) 5 62 21 67 18; email continued.airworthiness@atr.fr; Internet http://www.aerochain.com.

(4) 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.

(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 February 16, 2016. Dionne Palermo, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 2016–03689 Filed 2–25–16; 8:45 am]

**BILLING CODE 4910–13–P**

**DEPARTMENT OF TRANSPORTATION**

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2015–3146; Directorate Identifier 2014–NM–249–AD; Amendment**  **39–18411; AD 2016–04–17]**

**RIN 2120–AA64**

**Airworthiness Directives; The Boeing Company Airplanes** 

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

**ACTION :**  Final rule.

**SUMMARY :**  We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 777–200 series airplanes. This AD was prompted by an evaluation by the design approval holder (DAH) indicating that the skin lap splices at certain stringers in certain fuselage sections are subject to widespread fatigue damage (WFD) on aging Model 777 airplanes that have accumulated at least 45,000 total flight cycles. This AD requires inspections to detect cracking of fuselage skin lap splices in certain fuselage sections, and corrective actions if necessary; modification of left-side and right-side lap splices; and post-modification repetitive inspections for cracks in the modified lap splices, and corrective actions if necessary. We are issuing this AD to detect and correct fatigue cracking of the skin lap splices, and consequent risk of sudden decompression and the inability to sustain limit flight and pressure loads.

**DATES :**  This AD is effective April 1,
2016.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of April 1, 2016.

**ADDRESSES :**  For service information identified in this final rule, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P. O. Box 3707, MC 2H–65, Seattle, WA 98124–2207; telephone 206–544–5000, extension 1; fax 206–766–5680; Internet https://www.myboeingfleet.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–
3146. 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– 3146; 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 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 20590.

**FOR FURTHER INFORMATION CONTACT :**  Eric Lin, Aerospace Engineer, Airframe Branch, ANM–120S, FAA, Seattle Aircraft Certification Office (ACO), 1601 Lind Avenue SW., Renton, WA 98057– 3356; phone: 425–917–6412; fax: 425– 917–6590; email: Eric.Lin@faa.gov.

**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 The Boeing Company Model 777–200 series airplanes. The NPRM published in the Federal Register on August 25, 2015 (80 FR 51488) (‘‘the NPRM’’). The NPRM was prompted by an evaluation by the DAH indicating that the skin lap splices at certain stringers in certain fuselage sections are subject to WFD on aging airplanes (airplanes that have accumulated at least 45,000 total flight cycles). The NPRM proposed to require inspections to detect cracking of fuselage skin lap splices in certain fuselage sections, and corrective actions if necessary; modification of left-sideand right-side lap splices; and postmodification repetitive inspections for cracks in the modified lap splices, and corrective actions if necessary. We are issuing this AD to detect and correct fatigue cracking of the skin lap splices, and consequent risk of sudden decompression and the inability to sustain limit flight and pressure loads.

Comments

We gave the public the opportunity to participate in developing this AD. The following presents the comments received on the NPRM and the FAA’s response to each comment. Support for the NPRM

An anonymous commenter expressed support for the NPRM.
Request To Revise WFD Criteria Definition

Boeing requested that we revise the NPRM to specify that DAH analysis indicates that potential multi-site damage that could lead to WFD does not occur until at least 45,000 total flight cycles on aging Model 777 airplanes.

We agree with the commenter’s request. We have revised the **SUMMARY** and Discussion sections of this final rule and paragraph (e) of this AD to specify that this AD was prompted by an evaluation by the DAH indicating that the skin lap splices at certain stringers in certain fuselage sections are subject to WFD on aging Model 777 airplanes that have accumulated at least 45,000 total flight cycles.

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 and minor editorial changes. We have determined that these minor changes:

• Are consistent with the intent that was proposed in the NPRM for correcting the unsafe condition; and

• Do not add any additional burden upon the public than was already proposed in the NPRM.

We also determined that these changes will not increase the economic