2013-05178. Airworthiness Directives; The Boeing Company Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to supersede an existing airworthiness directive (AD) that applies to certain The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, and 747SR series airplanes. The existing AD currently requires repetitive inspections to find cracking of the web, strap, inner chords, inner chord angle of the forward edge frame of the number 5 main entry door cutouts, the frame segment between stringers 16 and 31, and repair if necessary; and repetitive inspections for cracking of repairs. Since we issued that AD, we have received multiple reports of cracking outside of the previous fuselage inspection areas and a report of a crack that initiated at the aft edge of the inner chord rather than initiating at a fastener location, which was the previous cracking location. This proposed AD would expand the previous fuselage areas that are inspected for cracking. We are proposing this AD to detect and correct such cracks, which could cause damage to the adjacent body structure and could result in depressurization of the airplane in flight.

DATES:

We must receive comments on this proposed AD by April 22, 2013.

ADDRESSES:

You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
• Fax: [phone].
• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590.
• Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this proposed AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone [phone], extension 1; fax [phone]; Internet https://www.myboeingfleet.com. You may review copies of the 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.

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov;​; 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 proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (phone: [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Nathan Weigand, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office (ACO), 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: [phone]; fax: [phone]; email: [e-mail].

SUPPLEMENTARY INFORMATION:

 

Comments Invited

We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2013-0097; Directorate Identifier 2011-NM-243-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD because of those comments.

We will post all comments we receive, without change, to http://www.regulations.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD.

Discussion

On September 15, 2010, we issued AD 2010-20-08, Amendment 39-16442 (75 FR 61337, October 5, 2010), for certain Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, and 747SR series airplanes. That AD requires repetitive inspections to find cracking of the web, strap, inner chords, inner chord angle of the forward edge frame of the number 5 main entry door cutouts, the frame segment between stringers 16 and 31, and repair if necessary; and repetitive inspections for cracking of repairs. That AD resulted from additional reports of cracks that have been found in the strap and inner chord of the forward edge frame of the number 5 main entry door cutouts, between stringers 16 and 23. We issued that AD to detect and correct such cracks, which could cause damage to the adjacent body structure and could result in depressurization of the airplane in flight.

Actions Since Existing AD (75 FR 61337, October 5, 2010) Was Issued

Since we issued AD 2010-20-08, Amendment 39-16442 (75 FR 61337, October 5, 2010), we have received multiple reports of cracking outside of the previous fuselage inspection areas and a report of a crack that initiated at the aft edge of the inner chord rather than initiating at a fastener location, which was the previous cracking location.

Relevant Service Information

We reviewed Boeing Alert Service Bulletin 747-53A2450, Revision 7, dated November 2, 2011. For information on the procedures and compliance times, see this service information at http://www.regulations.gov by searching for Docket No. FAA-2013-0097.

FAA's Determination

We are proposing this AD because we evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of the same type design.

Proposed AD Requirements

This proposed AD would retain all requirements of AD 2010-20-08, Amendment 39-16442 (75 FR 61337, October 5, 2010). This proposed AD would also expand the previous fuselage areas that are inspected for cracking.

The phrase “related investigative actions” might be used in this proposed AD. “Related investigative actions” are follow-on actions that: (1) Are related to the primary actions, and (2) are actions that further investigate the nature of any condition found. Related investigative actions in an AD could include, for example, inspections.

In addition, the phrase “corrective actions” might be used in this proposed AD. “Corrective actions” are actions that correct or address any condition found. Corrective actions in an AD could include, for example, repairs.

Difference Between the Proposed AD and Relevant Service Information

Boeing Alert Service Bulletin 747-53A2450, Revision 7, dated November 2, 2011, specifies to contact the manufacturer for instructions on how to repair certain conditions, but this proposed AD would require repairing those conditions in one of the following ways:

• Using a method that we approve; or
• Using data that meet the certification basis of the airplane, and that have been approved by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization whom we have authorized to make those findings.

Costs of Compliance

We estimate that this proposed AD affects 151 airplanes of U.S. registry.

We estimate the following costs to comply with this proposed AD:

Estimated Costs

Action	Labor cost	Parts cost	Cost per product	Cost on U.S. operators
Inspections [retained actions from AD 2010-20-08, Amendment 39-16442 (75 FR 61337, October 5, 2010)]	Up to 44 work-hours × $85 per hour = $3,740 per inspection cycle	$0	Up to $3,740 per inspection cycle	Up to $564,740 per inspection cycle.
Inspections [new proposed action]	Up to 121 work-hours × $85 per hour = $10,285 per inspection cycle	0	Up to $10,285 per inspection cycle	Up to $1,553,035 per inspection cycle.

We have received no definitive data that would enable us to provide cost estimates for the on-condition actions specified in this proposed AD.

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 proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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 the proposed regulation:

(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.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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) 2010-20-08, Amendment 39-16442 ( 75 FR 61337, October 5, 2010), and adding the following new AD:

The Boeing Company: Docket No. FAA-2013-0097; Directorate Identifier 2011-NM-243-AD.

(a) Comments Due Date

The FAA must receive comments on this AD action by April 22, 2013.

(b) Affected ADs

This AD supersedes AD 2010-20-08, Amendment 39-16442 (75 FR 61337, October 5, 2010).

(c) Applicability

This AD applies to The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, and 747SR series airplanes, certificated in any category, having line numbers 1 through 1419 inclusive; except for Model 747-400 series airplanes that have been modified into the Model 747-400 large cargo freighter configuration.

(d) Subject

Joint Aircraft System Component (JASC)/Air Transport Association (ATA) of America Code 53, Fuselage.

(e) Unsafe Condition

This AD was prompted by multiple reports of cracking outside of the previous inspection areas and a report of a crack that initiated at the aft edge of the inner chord rather than initiating at a fastener location. We are issuing this AD to detect and correct such cracks, which could cause damage to the adjacent body structure and could result in a rapid depressurization of the airplane.

(f) Compliance

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

(g) Retained Repetitive Inspections for Frame Segment Between Stringers 23 and 31 (No Terminating Action)

This paragraph restates the requirements of paragraph (g) of AD 2010-20-08, Amendment 39-16442 (75 FR 61337, October 5, 2010). For airplanes having line numbers 1 through 1304 inclusive: Inspect the airplane for cracks between stringers 23 and 31 per Boeing Alert Service Bulletin 747-53A2450, Revision 2, including Appendix A, dated January 4, 2001; or Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009; at the later of the applicable times specified in paragraph (h) or (i) of this AD, per table 1 to paragraphs (g) and (h) of this AD, as follows. Where there are differences between the AD and Boeing Alert Service Bulletin 747-53A2450, Revision 2, including Appendix A, dated January 4, 2001; or Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009: the AD prevails.

Table 1 to Paragraphs (g) and (h) of This AD—Inspection Requirements

Type of inspection	Area to inspect
(1) Detailed Visual	Strap inner chords forward and aft of the web, and exposed web adjacent to the inner chords on station 2231 frame from stringers 23 through 31 per Figure 5 or Figure 6 of the service bulletins specified in paragraph (g) or (h) of this AD, as applicable.
(2) Surface High Frequency Eddy Current (HFEC)	Station 2231 inner chord angles at lower main sill interface per Figure 5 or Figure 6 of the service bulletins specified in paragraph (g) or (h) of this AD, as applicable.
(3) Open Hole HFEC	Station 2231 frame fastener locations per Figures 4 and 7, and either Figure 5 or 6 of the service bulletins specified in paragraph (g) or (h) of this AD, as applicable.
(4) Surface HFEC	Around fastener locations on station 2231 inner chords from stringers 23 through 31 per Figure 5 or Figure 6 of the service bulletins specified in paragraph (g) or (h) of this AD, as applicable.
(5) Low Frequency Eddy Current (LFEC)	Station 2231 frame strap in areas covered by the reveal per Figure 5 or Figure 6 of the service bulletins specified in paragraph (g) or (h) of this AD, as applicable.

Note 1 to paragraph (g) of this AD:

There is no terminating action currently available for the inspections required by paragraph (g) of this AD.

(h) Retained Compliance Times

This paragraph restates the requirements of paragraph (h) of AD 2010-20-08, Amendment 39-16442 (75 FR 61337, October 5, 2010). Do the inspections specified in paragraph (g) of this AD at the applicable times specified in paragraph (h)(1) or (h)(2) of this AD. Repeat the inspections at intervals not to exceed 3,000 flight cycles until the inspections required by paragraph (m) or (o) of this AD are done. Where there are differences between the AD and Boeing Alert Service Bulletin 747-53A2450, Revision 2, including Appendix A, dated January 4, 2001; or Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009: the AD prevails.

(1) Do the inspections per table 1 to paragraphs (g) and (h) of this AD at the applicable time specified in the logic diagram in Figure 1 of Boeing Alert Service Bulletin 747-53A2450, Revision 2, including Appendix A, dated January 4, 2001. Where the compliance time in the logic diagram specifies a compliance time beginning “from receipt of this service bulletin,” this AD requires that the compliance time begin “after September 12, 2001 (the effective date of AD 2001-16-02, Amendment 39-12370 (66 FR 41440, August 8, 2001)).”

(2) After November 9, 2010 (the effective date of AD 2010-20-08, Amendment 39-16442 (75 FR 61337, October 5, 2010)), do the inspections per table 1 to paragraphs (g) and (h) of this AD at the applicable compliance time specified in paragraph 1.E., “Compliance” of Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009. Where the compliance time in Boeing Alert Service Bulletin 747-53A2450, Revision 2, including Appendix A, dated January 4, 2001, specifies a compliance time beginning “after the date on Revision 2 of this service bulletin,” this AD requires that the compliance time begin “after September 12, 2001 (the effective date of AD 2001-16-02, Amendment 39-12370 (66 FR 41440, August 8, 2001)).”

(i) Retained Repetitive Inspections for Frame Segment Between Stringers 23 and 31

This paragraph restates the requirements of paragraph (i) of AD 2010-20-08, Amendment 39-16442 (75 FR 61337, October 5, 2010). Within 3,000 flight cycles after accomplishment of the inspections specified in Figure 1 of Boeing Alert Service Bulletin 747-53A2450, dated May 4, 2000; or Boeing Alert Service Bulletin 747-53A2450, Revision 1, dated July 6, 2000; repeat the inspections specified in paragraph (g) of this AD at intervals not to exceed 3,000 flight cycles until the inspections required by paragraph (m) or (o) of this AD are done. Where there are differences between the AD and Boeing Alert Service Bulletin 747-53A2450, Revision 2, dated January 4, 2001; or Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009: the AD prevails.

(j) Retained Additional Repetitive Inspections (for Frame Segment Between Stringers 16 and 23)

This paragraph restates the requirements of paragraph (j) of AD 2010-20-08, Amendment 39-16442 (75 FR 61337, October 5, 2010).

(1) For all airplanes: Before the accumulation of 16,000 total flight cycles, or within 1,500 flight cycles after November 9, 2010 (the effective date of AD 2010-20-08, Amendment 39-16442 (75 FR 61337, October 5, 2010)), whichever occurs later, do a detailed inspection, an open hole HFEC inspection, a surface HFEC inspection, and a subsurface LFEC inspection for cracking of the forward edge frame of the number 5 main entry door cutouts, at station 2231, between stringers 16 and 23; in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009. Repeat the inspections thereafter at intervals not to exceed 3,000 flight cycles.

(2) The part number of the nut for fastener code “K” in Figure 7 of Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009, should be “BACN10JC3CD,” instead of “BACB30JC3CD.” In addition, the part number of the optional nut for this fastener code should be “BACN10YR3CD,” instead of “BACN10YR4CD” in Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009.

(k) Retained Repetitive Inspections for Line Numbers 1305 and On (for Frame Segment Between Stringers 23 and 31)

This paragraph restates the requirements of paragraph (k) of AD 2010-20-08, Amendment 39-16442 (75 FR 61337, October 5, 2010). For airplanes having line numbers 1305 and on: Before the accumulation of 16,000 total flight cycles, or within 1,500 flight cycles after November 9, 2010 (the effective date of AD 2010-20-08, Amendment 39-16442 (75 FR 61337, October 5, 2010)), whichever occurs later, do a detailed inspection, an open hole HFEC inspection, a surface HFEC inspection, and a subsurface LFEC inspection for cracking of the forward edge frame of the number 5 main entry door cutouts, at station 2231, between stringers 23 and 31; in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009. Repeat the inspections thereafter at intervals not to exceed 3,000 flight cycles.

(l) Retained Corrective Action for Paragraphs (g), (j), and (k) of This AD

This paragraph restates the requirements of paragraph (l) of AD 2010-20-08, Amendment 39-16442 (75 FR 61337, October 5, 2010). If any crack is found during any inspection required by paragraph (g), (j), or (k) of this AD, before further flight, repair the crack in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, in accordance with data meeting the type certification basis of the airplane approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) that has been authorized by the Manager, Seattle ACO, to make those findings; or in accordance with Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009; as applicable. For a repair method to be approved by the Manager, Seattle ACO, as required by this paragraph, the approval letter must specifically reference this AD. As of November 9, 2010 (the effective date of AD 2010-20-08), repair the crack using a method approved in accordance with the procedures specified in paragraph (s) of this AD.

(m) Retained Post-Repair Inspections

This paragraph restates the requirements of paragraph (m) of AD 2010-20-08, Amendment 39-16442 (75 FR 61337, October 5, 2010). Except as required by paragraph (n) of this AD, for airplanes on which the forward edge frame of the number 5 main entry door cutouts, at station 2231, between stringers 16 and 31, is repaired as specified in Boeing Alert Service Bulletin 747-53A2450: Within 3,000 flight cycles after doing the repair or within 1,500 flight cycles after November 9, 2010 (the effective date of AD 2010-20-08), whichever occurs later, do the detailed, LFEC, and HFEC inspections of the repaired area for cracks, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009. If no cracking is found, repeat the inspections thereafter at intervals not to exceed 3,000 flight cycles. If any crack is found: Before further flight, repair using a method approved in accordance with the procedures specified in paragraph (s) of this AD. Doing the inspections specified in paragraph (m) of this AD terminates the repetitive inspections required by paragraphs (g), (h), (i), (j), and (k) of this AD for the repaired area.

(n) Retained Post-Repair Inspection Restriction

This paragraph restates the requirements of paragraph (n) of AD 2010-20-08, Amendment 39-16442 (75 FR 61337, October 5, 2010). For any frame that is repaired in accordance with a method other than the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009: Do the inspection in accordance with a method approved in accordance with the procedures specified in paragraph (s) of this AD.

(o) New Repetitive Inspections With Expanded Inspection Area

Before the accumulation of 16,000 total flight cycles, or within 3,000 flight cycles after the effective date of this AD, whichever occurs later, do the inspections required by paragraphs (o)(1) through (o)(5) of this AD, except as specified in paragraph (p) of this AD. Do all actions required by this paragraph in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2450, Revision 7, dated November 2, 2011. Repeat the inspections thereafter at the applicable times specified in Paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2450, Revision 7, dated November 2, 2011. Accomplishment of the initial inspections required by this paragraph terminates the requirements of paragraphs (g) through (k) of this AD.

(1) Do a detailed inspection for cracking on the frame strap, inner chords forward and aft of the web, and exposed web adjacent to the inner chords from stringer 15 to 31.

(2) Do an HFEC inspection of the station 2231 frame fastener locations for cracking from stringer 16 to 31, including locations common to the upper main sill strap and stringer clip at stringer 16.

(3) Do an HFEC inspection for cracking of the frame inner chords around the fastener heads from stringer 15 to 31.

(4) Do an HFEC inspection for cracking of the aft edge of the aft inner chord, of the forward edge of the forward inner chord, and of the forward and aft edges of the frame strap from stringer 15 to 31.

(5) Do an LFEC inspection for cracking of the station 2231 frame strap from stringer 16 to 31 in areas covered by the reveal.

(p) New Post-Repair Inspection for Repaired Areas

For airplanes on which the post-repair inspections are being done as specified in paragraph (m) of this AD: For the repaired area only, continue the inspections as specified in paragraph (m) of this AD in lieu of the inspections specified in paragraph (o) of this AD.

(q) New Corrective Action

If any cracking is found during any inspection required by paragraph (o), (p), or (r) of this AD: Before further flight, repair the cracking using a method approved in accordance with the procedures specified in paragraph (s) of this AD.

(r) New Post-Repair Repetitive Inspections and Corrective Action

For any airplane repaired as specified in paragraph (q) of this AD: Within 3,000 flight cycles after doing the repair, do detailed, LFEC, and HFEC inspections of the repaired area for cracking, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2450, Revision 7, dated November 2, 2011. If no cracking is found, repeat the inspections thereafter at intervals not to exceed 3,000 flight cycles. If any cracking is found: Before further flight, do the actions specified in paragraph (q) of this AD.

(s) Alternative Methods of Compliance (AMOCs)

(1) The Manager, Seattle 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 the Related Information section of this AD. Information may be emailed to: [e-mail].

(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, Seattle 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 in accordance with AD 2010-20-08, Amendment 39-16442 (75 FR 61337, October 5, 2010), are approved as AMOCs for the corresponding provisions of paragraphs (g) through (m) of this AD.

(5) AMOCs approved previously in accordance with AD 2010-20-08, Amendment 39-16442 (75 FR 61337, October 5, 2010), that have post-repair inspections, are approved as AMOCs for the corresponding provisions of paragraph (o) of this AD for the repaired area only.

(t) Related Information

(1) For more information about this AD, Nathan Weigand, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office (ACO), 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: [phone]; fax: [phone]; email: [e-mail].

(2) For 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; telephone [phone], extension 1; fax [phone]; Internet https://www.myboeingfleet.com. You may review copies of the 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.

Issued in Renton, Washington, on February 25, 2013.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.