2012-20470. 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 all The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. The existing AD currently requires repetitive inspections to detect cracking of the lower corners of the door frame and cross beam of the forward cargo door, and corrective actions if necessary. The existing AD also requires eventual modification of the outboard radius of the lower corners of the door frame and reinforcement of the cross beam of the forward cargo door, which would constitute terminating action for the existing repetitive inspections. Since we issued that AD, we have received additional reports of fatigue cracking in the radius of the lower frames and in the lower number 5 cross beam of the forward cargo door. This proposed AD would revise the compliance times for the preventive modification; add certain inspections for cracks in the number 5 cross beam of the forward cargo door; and add inspections of the number 4 cross beam if cracks are found in the number 5 cross beam, and corrective actions if necessary. For certain airplanes, this proposed AD would also add a one-time inspection for airplanes previously modified or repaired, and a one-time inspection of the reinforcement angle for excessive shimming or fastener pull-up, and corrective actions if necessary. We are proposing this AD to prevent fatigue cracking of the lower corners of the door frame and number 5 cross beam of the forward cargo door, which could result in rapid depressurization of the airplane.

DATES:

We must receive comments on this proposed AD by October 5, 2012.

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 AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, Washington 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, Washington. 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:

Alan Pohl, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton, Washington 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-2012-0855; Directorate Identifier 2011-NM-136-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 March 31, 2000, we issued AD 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000), for Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. That AD requires repetitive inspections to detect cracking of the lower corners of the door frame and cross beam of the forward cargo door, and corrective actions, if necessary. That AD also requires eventual modification of the outboard radius of the lower corners of the door frame and reinforcement of the cross beam of the forward cargo door, which would constitute terminating action for the repetitive inspections. That AD resulted from reports indicating that fatigue cracks were detected in the lower corners of the door frame and cross beam of the forward cargo door. We issued that AD to prevent fatigue cracking of the lower corners of the door frame and cross beam of the forward cargo door, which could result in rapid depressurization of the airplane.

Actions Since AD 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000) Was Issued

Since we issued AD 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000), we have received additional reports of fatigue cracking in the radius of the lower frames and in the Web of the number 5 lower cross beam of the forward cargo door. One report was of a rapid loss of cabin pressure during descent, as a result of a door crack. Other reports indicated improper nesting when installing the aft reinforcement angle during accomplishment of the modification specified in Boeing Service Bulletin 737-52-1100, Revision 2, dated March 31, 1994; and Boeing Alert Service Bulletin 737-52A1100, Revision 3, dated July 20, 2000.

Relevant Service Information

We reviewed Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011; and Boeing Special Attention Service Bulletin 737-52-1149, dated December 11, 2003. For information on the procedures and compliance times, see this service information at http://www.regulations.gov.

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 these same type designs.

Proposed AD Requirements

This proposed AD would retain all of the requirements of AD 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000). This proposed AD would also require accomplishing the actions specified in the service information described previously, except as discussed under “Differences Between the Proposed AD and the Service Information.” Related investigative actions include inspecting the number 4 cross beam on the forward cargo door for cracking if cracking is found on the number 5 cross beam, a one-time high frequency eddy current inspection for cracking of the lower corner frame, and a one-time inspection of the reinforcement angle. Corrective actions include the following: Installing a preventive modification, replacing the frame and repairing any cracking, repairing or replacing the number 5 cross beam, and replacing the reinforcement angle.

Explanation of Changes Made to Existing Requirements

The compliance times required by AD 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000), are specified in flight cycles on the airplane. However, the compliance times in the new actions specified in the revised service information are specified in door flight cycles, which are flight cycles accumulated on the forward cargo doors. These doors are interchangeable between airplanes and they are often interchanged. Since the unsafe condition stems from the total flight cycles accumulated on the door and not on the airplane itself, this proposed AD will specify door flight cycles for the new compliance times.

We have changed all references to a “detailed visual inspection” in the retained requirements of the existing AD to a “detailed inspection” in this proposed AD.

Boeing Commercial Airplanes has received an ODA. We have revised the retained requirements of the existing AD to delegate the authority to approve an alternative method of compliance for any repair required by this proposed AD to the Boeing Commercial Airplanes ODA rather than a Designated Engineering Representative (DER).

We have included Note 2 of the restated requirements of AD 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000), in paragraph (h) of this proposed AD. Note 3 of the restated requirements of AD 2000-07-06 is no longer applicable and has been removed from this proposed AD. These changes do not add any additional burden on the public with regard to the restated requirements of the existing AD.

We have added Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011, to paragraph (i)(2) of this AD as the source of service information for accomplishing the preventive modification and the reinforcement modification.

Differences Between the Proposed AD and the Service Information

Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 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:

• In accordance with a method that we approve; or
• Using data that meet the certification basis of the airplane, and that have been approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) whom we have authorized to make those findings.

Changes to Existing AD 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000) Format

This proposed AD would retain all requirements of AD 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000). Since AD 2000-07-06 was issued, the AD format has been revised, and certain paragraphs have been rearranged. As a result, the corresponding paragraph identifiers have changed in this proposed AD, as listed in the following table:

Revised Paragraph Identifiers

Requirement in AD 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000)	Corresponding requirement in this proposed AD
paragraph (a)	paragraph (g)
paragraph (b)	paragraph (h)
paragraph (c)	paragraph (i)
paragraph (d)	paragraph (j)

Explanation of Change to Costs of Compliance

Since issuance of AD 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000), we have increased the labor rate used in the Costs of Compliance from $80 per work-hour to $85 per work-hour. The Costs of Compliance information, below, reflects this increase in the specified labor rate.

Costs of Compliance

We estimate that this proposed AD affects 581 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 from AD 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000)	1 work-hour × $85 per hour = $85 per inspection cycle	$0	$85 per inspection cycle	$49,385 per inspection cycle.
Modification retained from AD 2000-07-06	18 work-hours × $85 per hour = $1,530	$1,865	$3,395	$1,972,495.
Inspections, new proposed action	9 work-hours × $85 per hour = $765	$0	$765	$444,465.

We estimate the following costs to do any necessary modifications that would be required based on the results of the proposed inspections. We have no way of determining the number of aircraft that might need these modifications:

On-Condition Costs

Action	Labor cost	Parts cost	Cost per product
Modification	84 work-hours × $85 per hour = $7,140	$12,395	$19,535

We have received no definitive data that would enable us to provide cost estimates for the on-condition repairs/replacements 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) 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000), and adding the following new AD:

The Boeing Company: Docket No. FAA-2012-0855; Directorate Identifier 2011-NM-136-AD.

(a) Comments Due Date

The FAA must receive comments on this AD action by October 5, 2012.

(b) Affected ADs

This AD supersedes AD 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000).

(c) Applicability

This AD applies to all The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes, certificated in any category.

(d) Subject

Joint Aircraft System Component (JASC)/Air Transport Association (ATA) of America Code 52, Doors.

(e) Unsafe Condition

This AD was prompted by additional reports of fatigue cracking in the radius of the lower frames and in the lower number 5 cross beam of the forward cargo door. We are issuing this AD to prevent fatigue cracking of the lower corners of the door frame and number 5 cross beam of the forward cargo door, which could result in rapid depressurization of the airplane.

(f) Compliance

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

(g) Retained High Frequency Eddy Current (HFEC) Initial/Repetitive Inspections

This paragraph restates the requirements of paragraph (a) of AD 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000), with revised service information. Within 1 year or 4,500 flight cycles after May 16, 2000 (the effective date of AD 2000-07-06), whichever occurs later, perform an HFEC inspection to detect cracking of the lower corners (forward and aft) of the door frame of the forward cargo door, in accordance with Boeing 737 Nondestructive Test (NDT) Manual, D6-37239, Part 6, Section 51-00-00, Figure 4, dated August 5, 1997, or April 5, 2007, or Figure 23, dated August 5, 1997 or April 5, 2004, as applicable.

(1) If no cracking is detected, repeat the HFEC inspection thereafter at intervals not to exceed 4,500 flight cycles, until the requirements of paragraph (i) of this AD have been accomplished.

(2) If any cracking is detected during any inspection required by paragraph (g) of this AD, prior to further flight, accomplish the requirements of paragraphs (g)(2)(i) and (g)(2)(ii) of this AD, which constitute terminating action for the repetitive inspections required by paragraph (g)(1) of this AD.

(i) Accomplish the requirements of paragraph (g)(2)(i)(A) or (g)(2)(i)(B) of this AD, and install a cross beam repair and reinforcement modification of the cross beam, in accordance with Boeing Service Bulletin 737-52-1100, Revision 2, dated March 31, 1994.

(A) Repair the door frame of the forward cargo door in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate; or 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 such findings. For a repair or modification method to be approved by the Manager, Seattle ACO, as required by this paragraph, and paragraphs (g)(2)(ii), (h)(2), (h)(3)(ii), and (i)(2) of this AD, the Manager's approval letter must specifically reference this AD.

(B) Replace the door frame of the forward cargo door with a new door frame, in accordance with Boeing Service Bulletin 737-52-1100, Revision 2, dated March 31, 1994.

(ii) Modify the repaired or replaced door frame of the forward cargo door, in accordance with a method approved by the Manager, Seattle ACO, or in accordance with data meeting the type certification basis of the airplane approved by the Boeing Commercial Airplanes ODA that has been authorized by the Manager, Seattle ACO, to make those findings.

Note 1 to paragraphs (g), (h), (i), and (j) of this AD:

Accomplishment of Boeing Service Bulletin 737-52-1100, Revision 2, dated March 31, 1994, does not supersede the requirements of AD 90-06-02, Amendment 39-6489 (55 FR 8372, March 7, 1990).

(h) Retained Initial Detailed Inspection and Repetitive Inspections

This paragraph restates the requirements of paragraph (b) of AD 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000). Within 1 year or 4,500 flight cycles after May 16, 2000 (the effective date of AD 2000-07-06), whichever occurs later, perform a detailed inspection to detect cracking of the cross beam (i.e., upper and lower chord and Web sections) of the forward cargo door, in accordance with Boeing Service Bulletin 737-52-1100, Revision 2, dated March 31, 1994. For the purposes of this AD, a detailed inspection is: “An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirror, magnifying lenses, etc., may be necessary. Surface cleaning and elaborate procedures may be required.”

(1) If no cracking is detected, repeat the inspection thereafter at intervals not to exceed 4,500 flight cycles until the requirements of paragraph (i) of this AD have been accomplished.

(2) If any cracking is detected on the lower chord section of the cross beam during any inspection required by paragraph (h) of this AD, prior to further flight, repair in accordance with a method approved by the Manager, Seattle ACO, or in accordance with data meeting the type certification basis of the airplane approved by the Boeing Commercial Airplanes ODA that has been authorized by the Manager, Seattle ACO, to make those findings.

(3) If any cracking is detected on any area excluding the lower chord section of the cross beam (i.e., upper chord and Web section) during any inspection required by paragraph (h) of this AD, prior to further flight, accomplish the requirements of paragraph (h)(3)(i) or (h)(3)(ii) of this AD, as applicable, which constitutes terminating action for the repetitive inspections required by paragraph (h)(1) of this AD.

(i) For airplanes with line numbers 1 through 1231: Install a cross beam repair and preventative modification of the outboard radius of the lower corners (forward and aft) of the door frame, in accordance with Boeing Service Bulletin 737-52-1100, Revision 2, dated March 31, 1994.

(ii) For airplanes with line numbers 1232 and subsequent: Install a cross beam repair and preventative modification of the outboard radius of the lower corners (forward and aft) of the door frame, in accordance with a method approved by the Manager, Seattle ACO, or in accordance with data meeting the type certification basis of the airplane approved by the Boeing Commercial Airplanes ODA that has been authorized by the Manager, Seattle ACO, to make those findings.

(i) Retained Terminating Action

This paragraph restates the requirements of paragraph (c) of AD 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000), with revised service information. Within 4 years or 12,000 flight cycles after May 16, 2000 (the effective date of AD 2000-07-06), whichever occurs later: Install the preventative modification of the outboard radius of the lower corners (forward and aft) of the door frame and the reinforcement modification of the cross beam of the forward cargo door, in accordance with paragraph (i)(1) or (i)(2) of this AD, as applicable. Accomplishment of paragraph (i)(1) or (i)(2) of this AD, as applicable, constitutes terminating action for the repetitive inspections required by paragraphs (g)(1) and (h)(1) of this AD.

(1) For airplanes with line numbers 1 through 1231: Accomplish the preventative modification and the reinforcement modification, in accordance with Boeing Service Bulletin 737-52-1100, Revision 2, dated March 31, 1994.

(2) For airplanes with line numbers 1232 and subsequent: Accomplish the preventative modification and the reinforcement modification, in accordance with a method approved by the Manager, Seattle ACO, or in accordance with data meeting the type certification basis of the airplane approved by the Boeing Commercial Airplanes ODA that has been authorized by the Manager, Seattle ACO, to make those findings; or in accordance with Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011. As of the effective date of this AD, use only Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011, to accomplish the modifications required by this paragraph.

(j) Retained Action for Airplanes on Which Modifications Were Accomplished Previously

This paragraph restates the requirements of paragraph (d) of AD 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000). For all airplanes on which modifications of the forward lower corner of the door frame and the cross beam of the forward cargo door were accomplished in accordance with Boeing Service Bulletin 737-52-1100, dated August 25, 1988, or Revision 1, dated July 20, 1989; or in accordance with the requirements of AD 90-06-02, Amendment 39-6489 (55 FR 8372, March 7, 1990): Within 4 years or 12,000 flight cycles after May 16, 2000 (the effective date of AD 2000-07-06), whichever occurs later, install the reinforcement modification of the aft corner of the door frame of the forward cargo door, in accordance with Boeing Service Bulletin 737-52-1100, Revision 2, dated March 31, 1994. Accomplishment of such modification constitutes terminating action for the repetitive inspections required by paragraphs (g)(1) and (h)(1) of this AD.

(k) New Inspections and Corrective Actions

Except as provided by paragraphs (m)(1) and (m)(2) of this AD: At the applicable time specified in paragraph 1.E, “Compliance,” of Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011, do the inspections required by paragraphs (k)(1) and (k)(2) of this AD, as applicable. Do all applicable related investigative and corrective actions before further flight, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011; except as required by paragraph (m)(3) of this AD. Accomplishment of the inspections required by paragraph (k) of this AD terminates the requirements of the repetitive inspections required by paragraphs (g)(1) and (h)(1) of this AD. If any cracking is found in the number 4 cross beam, before further flight, repair in accordance with Boeing Special Attention Service Bulletin 737-52-1149, dated December 11, 2003.

Note 2 to paragraph (k) of this AD:

Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011, refers to Boeing Special Attention Service Bulletin 737-52-1149, dated December 11, 2003, as an additional source of guidance for the inspection for cracks of the number 4 cross beam.

(1) For airplanes identified in Tables 1 and 2 of paragraph 1.E, “Compliance,” of Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011: Do a one-time HFEC inspection of the applicable location for cracks, in accordance with the Work Instructions, Part I, of Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011.

(2) For airplanes identified in Table 3 of paragraph 1.E, “Compliance,” of Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011: Do a one-time general visual inspection of the reinforcement angle for excessive shimming or fastener pull-up, in accordance with the Work Instructions, Part III, of Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011.

(l) No Supplemental Structural Inspections Required by This AD

(1) The supplemental structural inspections specified in Table 4 of paragraph 1.E., “Compliance,” and Part 5 of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011, are not required by this AD.

(2) The supplemental structural inspections specified in Table 4 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011, may be used in support of compliance with section 121.1109(c)(2) or 129.109(c)(2) of the Federal Aviation Regulations (14 CFR 121.1109(c)(2) or 14 CFR 129.109(c)(2)). The corresponding actions specified in the Accomplishment Instructions of Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011, are not required by this AD.

(m) Exceptions to Certain Service Information

(1) Where paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011, specifies a compliance time relative to the Revision 5 issue date of the service bulletin, this AD requires compliance within the specified compliance time after the effective date of this AD.

(2) Where Table 1, “Condition” column of Paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011, specifies “airplanes without either the repair or modification accomplished in accordance with previous releases of this service bulletin,” the corresponding condition in this AD is for “airplanes on which either a repair or modification was not accomplished before the effective date of this AD.''

(3) Where Boeing Alert Service Bulletin 737-52A1100, Revision 5, dated February 14, 2011, specifies to contact Boeing for certain actions: Before further flight, do the repair using a method approved in accordance with the procedures specified in paragraph (n)(1) of this AD.

(n) Alternative Methods of Compliance (AMOCs)

(1) The Manager, Seattle ACO, 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 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 2000-07-06, Amendment 39-11660 (65 FR 19302, April 11, 2000), are approved as AMOCs for the corresponding requirements of this AD.

(o) Related Information

(1) For more information about this AD, contact Alan Pohl, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle ACO, 1601 Lind Avenue SW., Renton, Washington 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, Washington 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, Washington. For information on the availability of this material at the FAA, call 425-227-1221.

Issued in Renton, Washington, on August 13, 2012.

John P. Piccola,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.