2013-12618. Airworthiness Directives; The Boeing Company Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 747 airplanes. This proposed AD was prompted by reports of cracking in the forward and aft inner chord of the body station (BS) 2598 bulkhead near the upper corners of the cutout for the horizontal stabilizer rear spar, and cracking in the bulkhead upper and lower web panels near the inner chord to shear deck connection. This proposed AD would require doing repetitive inspections for cracking in the bulkhead splice fitting, frame supports, forward and aft inner chords, and floor support; doing an inspection for cracking in the bulkhead upper web, doubler, and bulkhead lower web; and corrective actions if necessary; for certain airplanes, inspections for cracking in the repaired area of the bulkhead, and corrective actions if necessary; for certain airplanes, support frame modification and support frame inspections, and related investigative and corrective actions, if necessary; for certain airplanes, repetitive support frame post-modification inspections and inspections for cracking in the hinge support, and related investigative and corrective actions if necessary; for certain airplanes, a one-time inspection of the frame web and upper shear deck (floor support) chord aft side for fasteners; and a one-time inspection of the upper forward inner chord, frame support fitting and splice fitting, for the installation of certain fasteners; and related investigative and corrective actions if necessary; for certain airplanes, a one-time inspection of the upper forward inner chord, frame support fitting and splice fitting for the installation of certain fasteners; a one-time inspection for any repair installed on the left and right side of the aft inner chord, and related investigative and corrective actions, if necessary; for certain airplanes, a one-time inspection of the support frame outer chord for cracking, and repair if necessary; and repetitive support frame post-repair inspections, and corrective actions, if necessary. We are proposing this AD to detect and correct fatigue cracking of the BS 2598 bulkhead structure, which could adversely affect the structural integrity of the bulkhead and the horizontal stabilizer support structure and result in loss of controllability of the airplane.

DATES:

We must receive comments on this proposed AD by July 12, 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 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.

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:

Bill Ashforth, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 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 proposal. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2013-0425; Directorate Identifier 2012-NM-224-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

We received reports of cracking in the forward and aft inner chord of the BS 2598 bulkhead near the upper corners of the cutout for the horizontal stabilizer rear spar, and cracking in the bulkhead upper and lower web panels near the inner chord to shear deck connection. This condition, if not corrected, could result in fatigue cracking of the BS 2598 bulkhead structure, which could result in inability of the structure to carry horizontal stabilizer flight loads, and loss of controllability of the airplane.

Relevant Service Information

We reviewed Boeing Alert Service Bulletin 747-53A2427, Revision 6, dated July 14, 2011; and Boeing Alert Service Bulletin 747-53A2473, Revision 4, dated December 1, 2011. For information on the procedures and compliance times, see this service information at http://www.regulations.gov by searching for Docket No. FAA-2013-0425.

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 require accomplishing the actions specified in the service information described previously, except as discussed under “Differences Between the Proposed AD and the Service Information.”

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.

Differences Between the Proposed AD and the Service Information

Where Part 1 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2427, Revision 6, dated July 14, 2011, specifies accomplishing inspections for cracks in forward and aft inner chords, splice fittings, floor supports, and upper and lower web panels, this AD also requires doing an open-hole high frequency eddy current (HFEC) inspection of the doubler. Figure 2 of Boeing Alert Service Bulletin 747-53A2427, Revision 6, dated July 14, 2011, includes the inspections.

Where paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2427, Revision 6, dated July 14, 2011; or 747-53A2473, Revision 4, dated December 1, 2011; specify to contact Boeing for repair data and do the repair, this AD requires doing those repairs in accordance with a method approved by the FAA.

If cracking is found in any doubler during any inspection specified by paragraph (g) of this proposed AD, this proposed AD would require repairing using a method approved in accordance with the procedures specified in paragraph (o) of this AD.

Costs of Compliance

We estimate that this proposed AD affects 165 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
Inspection	24 work-hours × $85 per hour = $2,040 per inspection cycle	$0	$2,040 per inspection cycle	$336,600 per inspection cycle.
Support frame modification	315 work-hours × $85 per hour = $26,775	0	$26,775	Up to $4,417,875.
Support frame upper corner fastener inspection	16 work-hours × $85 per hour = $1,360	0	$1,360	Up to $224,400.
Support frame post-modification inspection	200 work hours × $85 per hour = $17,000	0	$17,000	$2,805,000.

We have received no definitive data that would enable us to provide a cost estimate 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 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 this 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 adding the following new airworthiness directive (AD):

The Boeing Company: Docket No. FAA-2013-0425; Directorate Identifier 2012-NM-224-AD.

(a) Comments Due Date

We must receive comments by July 12, 2013.

(b) Affected ADs

This AD affects AD 2010-14-07, Amendment 39-16352 (75 FR 38001, July 1, 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, 747SR, and 747SP series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 747-53A2427, Revision 6, dated July 14, 2011.

(d) Subject

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

(e) Unsafe Condition

This AD was prompted by reports of cracking in the forward and aft inner chord of the body station (BS) 2598 bulkhead near the upper corners of the cutout for the horizontal stabilizer rear spar, and cracking in the bulkhead upper and lower web panels near the inner chord to shear deck connection. We are issuing this AD to detect and correct fatigue cracking of the BS 2598 bulkhead structure, which could adversely affect the structural integrity of the bulkhead and the horizontal stabilizer support structure and result in loss of controllability of the airplane.

(f) Compliance

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

(g) Inspections of the Bulkhead (Support Frame)

For airplanes on which the bulkhead (support frame) modification specified in Boeing Service Bulletin 747-53A2473 has not been accomplished: At the applicable times specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2427, Revision 6, dated July 14, 2011, except as provided by paragraph (m)(1), (m)(2), or (m)(3), as applicable, of this AD, do an open-hole and surface high frequency eddy current (HFEC) inspection for cracking in the bulkhead (support frame) which includes the bulkhead splice fitting, frame supports, forward and aft inner chords, and floor support; do a surface HFEC inspection for cracking in the bulkhead upper web and doubler; do an open-hole and surface HFEC inspection for cracking in the bulkhead lower web; and do all applicable corrective actions; in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2427, Revision 6, dated July 14, 2011, except as required by paragraphs (m)(4), (m)(5) and (m)(6) of this AD, and except as provided by paragraph (h) of this AD. Do all applicable corrective actions before further flight. Repeat the applicable inspections, thereafter, at the applicable times in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2427, Revision 6, dated July 14, 2011. Doing the modification required by paragraph (j) of this AD terminates the repetitive inspections required by this paragraph.

(h) Interim Modification

For airplanes in groups 1 and 2 as identified in Boeing Alert Service Bulletin 747-53A2427, Revision 6, dated July 14, 2011, on which no cracking was found during any inspection required by paragraph (g) of this AD: At the applicable times specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2427, Revision 6, dated July 14, 2011, except as provided by paragraph (m)(2) of this AD, do the interim modification, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2427, Revision 6, dated July 14, 2011. Doing the interim modification terminates the repetitive inspection requirement of paragraph (g) of this AD in the area of the modification only. The repetitive inspections of the bulkhead lower web, as specified in paragraph (g) of this AD, must be done. If the aft inner chord repair or upper web repair specified in Boeing Alert Service Bulletin 747-53A2427, Revision 6, dated July 14, 2011, has been accomplished, an interim modification on the side of the airplane that has the repair is not required by this paragraph.

(i) Post-Repair Inspection or Post-Interim Modification Inspection

For airplanes on which an interim modification, or aft inner chord repair, or upper web repair has been done as specified in paragraph (g) or (h) of this AD: At the applicable times specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2427, Revision 6, dated July 14, 2011, except as specified in paragraph (m)(1), (m)(2), or (m)(3), as applicable, of this AD, do the actions specified in paragraph (i)(1) and (i)(2) of this AD, and all applicable corrective actions, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2427, Revision 6, dated July 14, 2011, except as required by paragraph (m)(4) of this AD. Do all applicable corrective actions before further flight. Repeat the inspections thereafter at the applicable intervals specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2427, Revision 6, dated July 14, 2011. Doing the modification required by paragraph (j) of this AD terminates the repetitive inspections required by this paragraph.

(1) Do forward side surface HFEC inspections for cracking of the bulkhead forward inner chord, splice fitting, and frame support.

(2) Do surface and open-hole HFEC inspections for cracking in the repaired area of the bulkhead.

(j) Bulkhead (Support Frame) Modification and Inspections

For airplanes on which the bulkhead (support frame) modification specified in Boeing Alert Service Bulletin 747-53A2473, dated March 24, 2005; Revision 1, dated February 20, 2007; Revision 2, dated August 28, 2009; Revision 3, dated July 14, 2011; or Revision 4, dated December 1, 2011, has not been done as of the effective date of this AD: At the applicable time in tables 2 and 3 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2473, Revision 4, dated December 1, 2011, do the bulkhead (support frame) modification and inspections and all applicable related investigative and corrective actions; in accordance with steps 3.B.3., 3.B.4., and 3.B.5. of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2473, Revision 4, dated December 1, 2011, except as required by paragraph (m)(4) of this AD. Do all applicable related investigative and corrective actions before further flight. Doing the modification in this paragraph terminates the inspections required by paragraphs (g) and (i) of this AD.

(k) Post Modification Inspections

(1) For airplanes on which the bulkhead (support frame) modification has been done as specified in Boeing Service Bulletin 747-53A2473, dated March 24, 2005; Revision 1, dated February 20, 2007; Revision 2, dated August 28, 2009; Revision 3, dated July 14, 2011; or Revision 4, dated December 1, 2011: Except as provided by paragraphs (m)(7) and (m)(8) of this AD, at the applicable time in tables 6, 7, 8, and 9 of paragraph 1.E., “Compliance” of Boeing Service Bulletin 747-53A2473, Revision 4, dated December 1, 2011, do support frame post-modification inspections, and open-hole HFEC inspection for cracking in the hinge support, and do all applicable related investigative and corrective actions, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-53A2473, Revision 4, dated December 1, 2011, except as required by paragraph (m)(4). Do all applicable related investigative and corrective actions before further flight. Repeat the inspections thereafter at the applicable times in tables 6, 7, 8, and 9 of paragraph 1.E., “Compliance,” of Boeing Service Bulletin 747-53A2473, Revision 4, dated December 1, 2011.

(2) For airplanes on which the support frame modification has been done as specified in Boeing Service Bulletin 747-53A2473, Revision 1, dated February 20, 2007: Except as specified in paragraphs (m)(7) and (m)(8) of this AD, at the applicable time in tables 4 and 5 of paragraph 1.E., “Compliance” of Boeing Service Bulletin 747-53A2473, Revision 4, dated December 1, 2011, do a one-time general visual inspection of the frame web and upper shear deck (floor support) chord aft side for fasteners that were installed as part of an inner chord repair removal; and a one-time general visual inspection of the upper forward inner chord, frame support fitting and splice fitting, for the installation of certain fasteners; and do all applicable related investigative and corrective actions; in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-53A2473, Revision 4, dated December 1, 2011, except as required by paragraph (m)(4) of this AD. Do all applicable related investigative and corrective actions at the applicable times specified in tables 4 and 5 of paragraph 1.E., “Compliance” of Boeing Service Bulletin 747-53A2473, Revision 4, dated December 1, 2011.

(3) For airplanes on which the support frame modification has been done as specified in Boeing Service Bulletin 747-53A2473, dated March 24, 2005: Except as specified in paragraphs (m)(7) and (m)(8) of this AD, at the applicable time in tables 5 and 10 of paragraph 1.E., “Compliance” of Boeing Service Bulletin 747-53A2473, Revision 4, dated December 1, 2011, do a one-time general visual inspection of the upper forward inner chord, frame support fitting, and splice fitting for the installation of certain fasteners; a one-time general visual inspection for any repair installed on the left and right side of the aft inner chord; and do all applicable related investigative and corrective actions; in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-53A2473, Revision 4, dated December 1, 2011, except as required by paragraph (m)(4) of this AD. Do all applicable related investigative and corrective actions at the applicable times specified in tables 5 and 10 of paragraph 1.E., “Compliance” of Boeing Service Bulletin 747-53A2473, Revision 4, dated December 1, 2011.

(4) For airplanes on which a post-modification inspection was done in accordance with paragraph 3.B.8. of Part 1 of the Accomplishment Instructions of Boeing Service Bulletin 747-53A2473, Revision 3, dated July 14, 2011: Except as required by paragraphs (m)(7) and (m)(8) of this AD, at the applicable time in table 11 of paragraph 1.E., “Compliance” of Boeing Service Bulletin 747-53A2473, Revision 4, dated December 1, 2011, do a one-time surface HFEC inspection of the support frame outer chord for cracking, in accordance with Part 1 of the Accomplishment Instructions of Boeing Service Bulletin 747-53A2473, Revision 4, dated December 1, 2011. If any cracking is found, repair before further flight, using a method approved in accordance with the procedures specified in paragraph (o) of this AD.

(l) Post-Modification Post-Repair Inspections

For airplanes on which post-modification inspection cracks were repaired by doing the installation of an upper or lower corner post-modification web crack repair as specified in Boeing Service Bulletin 747-53A2473, Revision 4, dated December 1, 2011: At the applicable times specified in tables 6 and 8 of paragraph 1.E., “Compliance” of Boeing Service Bulletin 747-53A2473, Revision 4, dated December 1, 2011, do a bulkhead (support frame) post-repair inspection, and do all applicable corrective actions, in accordance with paragraph a., b., or c. of Part 4 of paragraph 3.B.8 of the Accomplishment Instructions of Boeing Service Bulletin 747-53A2473, Revision 4, dated December 1, 2011, as applicable, except as required by paragraph (m)(4) of this AD. Repeat the inspection, thereafter, at the applicable times specified in tables 6 and 8 of paragraph 1.E., “Compliance,” of Boeing Service Bulletin 747-53A2473, Revision 4, dated December 1, 2011.

(m) Exceptions

(1) Where Boeing Alert Service Bulletin 747-53A2427, Revision 6, dated July 14, 2011, specifies a compliance time after the date on Revision 2 of this service bulletin, this AD requires compliance within the specified compliance time as of August 28, 2001 (the effective date of AD 2001-15-03, Amendment 39-12337 (66 FR 38365, July 24, 2001)).

(2) Where Boeing Alert Service Bulletin 747-53A2427, Revision 6, dated July 14, 2011, specifies a compliance time after the date on Revision 4 of this service bulletin, this AD requires compliance within the specified compliance time as of April 13, 2006 (the effective date of AD 2006-05-06, Amendment 39-14503 (71 FR 12125, March 9, 2006)).

(3) Where Boeing Alert Service Bulletin 747-53A2427, Revision 6, dated July 14, 2011, specifies a compliance time after the date on Revision 6 of this service bulletin, this AD requires compliance within the specified compliance time “after the effective date of this AD.”

(4) If any cracking is found during any inspection required by this AD, and Boeing Alert Service Bulletin 747-53A2427, Revision 6, dated July 14, 2011; or Boeing Service Bulletin 747-53A2473, Revision 4, dated December 1, 2011; specifies to contact Boeing for appropriate action: Before further flight, repair the crack using a method approved in accordance with the procedures specified in paragraph (o) of this AD.

(5) If, during any inspection required by paragraph (g) of this AD, any cracking is found in the doubler, before further flight, repair, using a method approved in accordance with the procedures specified in paragraph (o) of this AD.

(6) Where Part 1 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2427, Revision 6, dated July 14, 2011, specifies accomplishing inspections for cracks for forward and aft inner chords, splice fittings, floor supports, and upper and lower web panels, this AD also requires doing an open-hole HFEC inspection of the doubler.

(7) Where Boeing Service Bulletin 747-53A2473, Revision 4, dated December 1, 2011, specifies a compliance time after the date on Revision 2 of the service bulletin, this AD requires compliance within the specified compliance time as of August 5, 2010 (the effective date of AD 2010-14-07, Amendment 39-16352 (75 FR 38001, July 1, 2010)).

(8) Where Boeing Service Bulletin 747-53A2473, Revision 4, dated December 1, 2011, specifies a compliance time after the date on Revision 3 or 4 of the service bulletin, this AD requires compliance within the specified compliance time “after the effective date of this AD.”

(n) Terminating Action for Certain Requirements of AD 2010-14-07, Amendment 39-16352 (75 FR 38001, July 1, 2010)

(1) Accomplishing the inspections, repairs, and modification in accordance with Boeing Service Bulletin 747-53A2473, Revision 4, dated December 1, 2011, is a terminating action for the corresponding inspections, repairs, and modification at the STA 2598 support frame required by paragraphs (i), (j), (k)(1), (m), (n), (o), (p), (q), (r), (s), (t), (u), and (v) of AD 2010-14-07, Amendment 39-16352 (75 FR 38001, July 1, 2010). When Boeing Service Bulletin 747-53A2473, Revision 4, dated December 1, 2011, specifies to contact Boeing for repair instructions, the repair instructions must be approved by the FAA in accordance with paragraph (o) of this AD. All provisions of AD 2010-14-07 that are not specifically referenced in this paragraph remain fully applicable and must be complied with.

(2) Accomplishing the inspections, repairs and interim modification in accordance with Boeing Service Bulletin 747-53A2427, Revision 6, dated July 14, 2011, is a terminating action for the corresponding inspections, repairs and interim modification at the STA 2598 bulkhead required by paragraphs (i), (j), (o), (s), (t), (u), and (v) of AD 2010-14-07, Amendment 39-16352 (75 FR 38001, July 1, 2010). When Boeing Service Bulletin 747-53A2427, Revision 6, dated July 14, 2011, specifies to contact Boeing for repair data, the repair data must be approved by the FAA in accordance with paragraph (o) of this AD. All provisions of AD 2010-14-07 that are not specifically reference in this paragraph remain fully applicable and must be complied with.

(o) 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.

(p) Related Information

(1) For more information about this AD, contact Bill Ashforth, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 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 May 17, 2013.

Jeffrey E. Duven,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.