06-3432. Airworthiness Directives; Boeing Model 747-200C and -200F Series Airplanes

AGENCY:

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

ACTION:

Final rule.

SUMMARY:

The FAA is superseding an existing airworthiness directive (AD), which applies to certain Boeing Model 747-200C and -200F series airplanes. That AD currently requires repetitive inspections to find fatigue cracking in the upper chord of the upper deck floor beams, and repair if necessary. For certain airplanes, the existing AD also provides an optional repair/modification, which extends certain repetitive inspection intervals. This new AD reduces the compliance time for all initial inspections and reduces the repetitive interval for a certain inspection. This AD results from new reports of cracks in the upper deck floor beams occurring at lower flight cycles. We are issuing this AD to find and fix cracking in certain upper deck floor beams. Such cracking could extend and sever floor beams at a floor panel attachment hole location and could result in rapid decompression and loss of controllability of the airplane.

DATES:

This AD becomes effective May 17, 2006.

The Director of the Federal Register approved the incorporation by reference of Boeing Alert Service Bulletin 747-53A2439, Revision 1, dated March 10, 2005, as listed in the AD as of May 17, 2006.

On March 15, 2004 (69 FR 5920, February 9, 2004), the Director of the Federal Register approved the incorporation by reference of Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001.

ADDRESSES:

You may examine the AD docket on the Internet at http://dms.dot.gov or in person at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC.

Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for service information identified in this AD.

FOR FURTHER INFORMATION CONTACT:

Ivan Li, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Examining the Docket

You may examine the airworthiness directive (AD) docket on the Internet at http://dms.dot.gov or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone [phone]) is located on the plaza level of the Nassif Building at the street address stated in the ADDRESSES section.

Discussion

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that supersedes AD 2004-03-11, amendment 39-13455 (69 FR 5920, February 9, 2004). The existing AD applies to certain Boeing Model 747-200C and -200F series airplanes. That NPRM was published in the Federal Register on September 16, 2005 (70 FR 54668). That NPRM proposed to require repetitive inspections to find fatigue cracking in the upper chord of the upper deck floor beams, and repair if necessary. For certain airplanes, the NPRM also proposed an optional repair/modification, which extends certain repetitive inspection intervals.

Comments

We provided the public the opportunity to participate in the development of this AD. We have considered the comments that have been received on the NPRM.

Request To Revise Initial Inspection Threshold for Certain Airplanes

For airplanes that have accumulated 17,000 or more total flight cycles, the Air Transport Association (ATA) on behalf of one of its members, Northwest Airlines, requests that we revise the grace period for the initial inspection threshold specified in paragraph (f)(2) of the NPRM from 90 days to 500 flight cycles. They state that this change would implement a definitive inspection limit to more accurately measure fatigue-related concerns and would align with operators' regularly scheduled heavy maintenance check.

We partially agree. We agree with ATA and Northwest Airlines that cracking of the affected upper deck floor beams is attributed to fatigue, and that a compliance time based on flight cycles is appropriate for inspecting for fatigue cracking. However, we do not agree with their request to revise the grace period for the inspections required by this AD. In developing an appropriate compliance time for this AD, we considered the safety implications, the airplane manufacturer's recommended compliance time, and normal maintenance schedules for the timely accomplishment of the inspections and repair if necessary. In consideration of these items, as well as the reports of significant cracking at the affected floor beams on airplanes that had accumulated as low as 19,580 total flight cycles, we have determined that the 90-day grace period specified in paragraph (f)(2) of this AD is appropriate. For high-cycle airplanes that have accumulated 17,000 or more total flight cycles as of the effective date of this AD, the 90-day grace period is merely a time that we provide the operators to plan for the necessary actions and to avoid immediate grounding of airplanes. This grace period will ensure an acceptable level of safety and will allow the required inspections to be done during scheduled maintenance intervals for most affected operators. However, under the provisions of paragraph (l) of the AD, we may approve requests for adjustments to the compliance time if data are submitted to substantiate that such an adjustment would provide an acceptable level of safety. Therefore, we find that no change to the final rule is necessary in this regard.

Request To Clearly Distinguish the Old and New Requirements

Boeing requests that we revise paragraphs (g)(1), (h)(1), and (h)(2) of the NPRM to more clearly distinguish between the old and new requirements. They state that those paragraphs specify requirements from AD 2004-03-11, as well as new requirements. They believe that this could cause operators to be confused as to which requirements to comply with. They also state that paragraphs (f) through (k) of the NPRM are under a header titled, “REQUIREMENTS OF AD 2004-03-11,” which would imply that those paragraphs have no new information.

We agree. For clarification purposes, we have revised the AD as follows:

• Revised the header “REQUIREMENTS OF AD 2004-03-11” to “RESTATEMENT OF REQUIREMENTS OF AD 2004-03-11, BUT WITH A NEW REDUCED THRESHOLD AND REDUCED REPETITIVE INTERVALS FOR CERTAIN FLOOR BEAMS”;
• Added a new header, “NEW REQUIREMENTS OF THIS AD”;
• Moved paragraphs (i) and (j) of the NPRM under the new header and reidentified paragraph (j) as paragraph (k);
• Moved the sentences in paragraphs (g), (g)(1), and (h)(1) that require operators to do the required actions, as of the effective date of this AD, in accordance with Boeing Alert Service Bulletin 747-53A2439, Revision 1, dated March 10, 2005; to new paragraph (j), “New Revision of Service Bulletin,” in the AD; and
• Clarified in paragraphs (h)(1) and (h)(2) that the repetitive inspection interval is 3,000 flight cycles, as shown in Figure 1 of the service bulletin.

Request To Delete Reference to Part 1 of the Service Bulletin in Paragraphs (g)(1) and (h)(1)

Boeing also requests that we delete the reference to “Part 1” of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, Revision 1, dated March 10, 2005, in the last sentence of paragraph (g)(1) and in the second sentence of paragraph (h)(1). They state that Revision 1 of the service bulletin specifies that repaired areas are inspected only in accordance with Part 6 of the Work Instructions, and that there is no path that could lead back to Part 1. They also state that paragraph (h) of the NPRM is relevant to repair and post-repair inspections, and that Part 1 applies to neither.

We partially agree. We agree with Boeing that Revision 1 of Boeing Alert Service Bulletin 747-53A2439 refers only to Part 6 for post-repair inspections, and that paragraph (h) is relevant to repair and post-repair inspections. Part 6 describes procedures for inspecting areas that have been repaired in accordance with Figure 8, 9, 10, or 12 of the service bulletin. However, we do not agree with them that the reference to Part 1 should be deleted. The procedures specified in Part 1 are applicable to areas that have been repaired by hole over-sizing only (without reinforcement) in accordance with Part 3. We find that no change to the AD is necessary in this regard.

Request To Clarify Repetitive Inspection Interval

Boeing also requests that we clarify the repetitive inspection intervals in paragraphs (g)(2)(i) through (g)(2)(iii) and (g)(2)(iii)(A) of the NPRM. Because paragraph (g)(2) of the NPRM specifies repetitive inspection requirements, they believe that specifying “repeat” in paragraphs (g)(2)(i) through (g)(2)(iii) is redundant. They also note that paragraphs (g)(2)(ii) and (g)(2)(iii) state, “Repeat that inspection * * *.” They point out that, at the time of any inspection if no crack is found, an operator has a choice of doing the inspection specified in paragraph (g) of the NPRM in accordance with Part 1 or 2 and thus the interval could change. Therefore, they suggest that the compliance time in paragraphs (g)(2)(i) through (g)(2)(iii) apply only to the “next inspection.”

We partially agree. We agree with Boeing that clarification is necessary. We have revised paragraph (g) to clarify that, during the repetitive inspections, any combination of the applicable inspection methods may be used, provided that the corresponding repetitive interval is used. We do not agree with the changes that they suggested to paragraph (g)(2)(iii)(A). We used that language to correspond with the requirements of paragraph (a)(2) of AD 2004-03-11, which has been revised and re-identified as paragraph (g)(2)(iii)(A) in this AD.

Request To Refer to Upper Chords Rather Than Airplanes

In addition, Boeing requests that paragraph (h) of the NPRM refer to “upper chords” instead of “airplanes.” They believe that some operators will inspect or have inspected some upper chords in accordance with Part 1 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001; or Revision 1, dated March 10, 2005; and will inspect or have inspected other chords in accordance with Part 2 of the Work Instructions due to more difficult access. They note that the service bulletin recommends the proposed inspection in accordance with Part 2 at some locations.

We partially agree. We agree with Boeing's rationale for revising paragraph (h). However, we find that using the term “areas” rather than “upper chord,” as they suggested, in that paragraph will capture all areas that are being inspected in accordance with paragraph (g) of this AD. We have revised paragraph (h) accordingly.

Request Not To Delay Repetitive Inspections if Optional Repair/Modification Is Done

In addition, Boeing requests that we delete the second sentence in paragraph (h). As an alternative if that sentence is not deleted, they request that the requirement be clarified in the preamble under “Differences Between the Proposed AD and Service Bulletin.” They state that Part 2 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001; and Revision 1, dated March 10, 2005; provides no instructions path for operators to jump from Part 2 to Part 3, because operators would not choose to do hole repairs if fasteners have not been removed and no cracks have been found.

We do not agree. As explained in the preamble of the NPRM under “Change to Existing AD,” this AD retains certain requirements of AD 2004-03-11. The optional repair/modification specified in paragraph (h) of this AD corresponds to requirements in paragraph (b) of AD 2004-03-11. As explained in the preamble under “Request To Expand Provisions for Optional Repair/Modification” of AD 2004-03-11, we added the second sentence of paragraph (h) of this AD (paragraph (b) of AD 2004-03-11) based on a request from Boeing. We have determined that providing the optional repair/modification specified in paragraph (h) is beneficial to operators. The repair procedures in Part 3 of the Work Instructions include procedures for doing an open hole high frequency eddy current inspection of the affected fastener holes. Therefore, we have determined that doing the optional repair/modification provides an acceptable level of safety and thus warrants an extension of the threshold for the initiation of the repetitive inspections required by paragraph (g)(2). In addition, we do not agree that this optional action differs from the service bulletin. We find that no change to the final rule is necessary in this regard.

Request To Add New Inspections and Reduce Inspection Threshold

Boeing also requests that, for floor beam chords at stations 440 and 520, we revise paragraph (h)(1) of the NPRM to lower the inspection threshold and to add new inspection requirements for a certain post-repair/modification. They state that analysis has shown that additional inspections and a reduced inspection threshold are needed of the holes in the flange adjacent to the trim-out.

We acknowledge Boeing's concern, but do not agree with their request. Since the suggested changes would expand the scope of the actions in this AD, additional rulemaking (i.e., supplemental NPRM) would be necessary to reopen the comment period. We find that to delay issuance of the AD would be inappropriate in light of the identified unsafe condition, and that the required inspections must be conducted to ensure continued safety. We may consider additional rulemaking, however, once the new inspection method is developed, approved, and available. We find that no change is necessary to this AD in this regard.

Request To Allow Not Counting Flight Cycles When Cabin Differential Is at 2.0 Pounds Per Square Inch (psi) or Less

Further, Boeing requests that we revise paragraph (i) of the NPRM to allow not counting flight cycles in which cabin differential pressure is at 2.0 psi or less, when determining the number of flight cycles for compliance times. They state that this change would be consistent with the previous requirements for these inspections and is a continuance of the allowance for the upper deck floor beams given in paragraph (c) of AD 2004-03-11.

We do not agree. There have been several instances on other in-service reports where analytical rationales, similar to that of the commenter, have indicated that pressurization cycles less than 2.0 psi should not be counted. However, when fleet records have been examined, the airplanes engaging in such operations are having the same or greater occurrences of crack findings compared to those on which all pressurized flights are counted. As a result, we carefully consider such matters based on all available factors, including individual operator's specific maintenance programs, technical rationale, and fleet experience. We have found that such provisions are applicable only to a small number of operators that may not pressurize their airplanes above 2.0 psi in all their flights. We have determined that the best way to handle such circumstances is for operators to request an alternative method of compliance (AMOC) in accordance with paragraph (l) of this AD, rather than increasing the complexity of the AD by addressing each operator's unique situation.

Request To Give Credit to Previously Approved AMOC

Boeing also requests that we revise paragraph (k)(3) of the NPRM (re-identified as paragraph (l)(3) in this AD) to add provisions for previously approved AMOCs that require post-modification/repair inspections. They contend that previously approved AMOCs meet the intent of paragraph (h) of the NPRM. They state that this change will reduce the need for new AMOCs.

We agree and have added a reference to paragraph (h) in paragraph (l)(3) of this AD.

Request To Refer to Supplemental Structural Inspection Document (SSID) AD

Lastly, Boeing requests that additional language be added to the NPRM to address its impact on AD 2004-07-22, amendment 39-13566 (69 FR 18250, April 7, 2004), which mandated the SSID program for Boeing Model 747 airplanes. (One correction of that AD was published in the Federal Register on April 13, 2004 (69 FR 19618); another correction was published on May 3, 2004 (69 FR 24063).) They state that, if the AD is adopted as proposed, operators will be required to do the SSID inspections and the inspections specified in Boeing Alert Service Bulletin 747-53A2439, Revision 1, without an allowance of doing the inspections specified in the service bulletin as a substitute for the SSID inspections. They also state that the inspections in the service bulletin provide damage detection as good as or better than SSID items F-19C for stations 340 through 420 inclusive, and 500; and F-20A for stations 440 and 520. In addition, they prefer that operators do the inspections in accordance with the service bulletin, because of the level of detailed instructions.

We do not agree. We acknowledge that doing the inspections specified in Boeing Alert Service Bulletin 747-53A2439, Revision 1, may be acceptable for compliance with certain requirements of AD 2004-07-22; however, no request for an AMOC to that AD has been submitted to us for approval in this regard. In addition, it is more appropriate to address AMOCs under the provisions of the applicable AD rather than a related AD. Under the provisions of paragraph (g) of AD 2004-07-22, we may consider requests for approval of an AMOC if sufficient data are submitted to substantiate that such action would provide an acceptable level of safety. We find that no change to this AD is necessary in this regard.

Clarification of AMOC Paragraph

We have revised this action to clarify the appropriate procedure for notifying the principal inspector before using any approved AMOC on any airplane to which the AMOC applies.

Conclusion

We have carefully reviewed the available data, including the comments that have been received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We have determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

Costs of Compliance

There are about 78 airplanes of the affected design in the worldwide fleet. This AD will affect about 21 airplanes of U.S. registry.

The inspections that are required by AD 2004-03-11 and retained in this AD take about 29 work hours per airplane, at an average labor rate of $65 per work hour. Based on these figures, the estimated cost of the currently required inspections for U.S. airplanes is $39,585, or $1,885 per airplane, per inspection cycle.

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 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 DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and

(3) 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.

We prepared a regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation.

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 Federal Aviation Administration (FAA) amends § 39.13 by removing amendment 39-13455 ( 69 FR 5920, February 9, 2004) and by adding the following new airworthiness directive (AD):

2006-08-02 Boeing: Amendment 39-14556. Docket No. FAA-2005-22423; Directorate Identifier 2005-NM-068-AD.

Effective Date

(a) This AD becomes effective May 17, 2006.

Affected ADs

(b) This AD supersedes AD 2004-03-11.

Applicability

(c) This AD applies to Boeing Model 747-200C and -200F series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001.

Unsafe Condition

(d) This AD results from new reports of cracks in the upper deck floor beams occurring at lower flight cycles. We are issuing this AD to find and fix cracking in certain upper deck floor beams, which could extend and sever floor beams at a floor panel attachment hole location and could result in rapid decompression and loss of controllability of the airplane.

Compliance

(e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

Restatement of Requirements of AD 2004-03-11, but With a New Reduced Threshold and Reduced Repetitive Intervals for Certain Floor Beams:

Initial Compliance Time at a New Reduced Threshold

(f) At the earliest of the times specified in paragraphs (f)(1) through (f)(3) of this AD, do the inspection required by paragraph (g) of this AD.

(1) Before the accumulation of 22,000 total flight cycles, or within 1,000 flight cycles after March 15, 2004 (the effective date of AD 2004-03-11), whichever occurs later.

(2) For airplanes with 17,000 or more total flight cycles as of the effective date of this AD: Before the accumulation of 18,000 total flight cycles, or within 90 days after the effective date of this AD, whichever occurs later.

(3) For airplanes with fewer than 17,000 total flight cycles as of the effective date of this AD: Before the accumulation of 15,000 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later.

Inspections at Reduced Intervals for Certain Floor Beams and Repair

(g) Do the applicable inspection to find fatigue cracking in the upper chord of the upper deck floor beams as specified in Part 1 (Open-Hole High Frequency Eddy Current (HFEC) Inspection Method) or Part 2 (Surface HFEC Inspection Method) of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001. Do the inspections per the service bulletin, except as provided by paragraph (j) of this AD. Any combination of the applicable inspection methods specified in Parts 1 and 2 may be used, provided that the corresponding repetitive inspection interval is used.

(1) If any crack is found, before further flight, repair per Part 3 (Upper Chord Repair) of the Work Instructions of the service bulletin; except where the service bulletin specifies to contact Boeing for appropriate action, before further flight, repair according to a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or according to data meeting the certification basis of the airplane approved by an a Boeing Company Designated Engineering Representative (DER) or Authorized Representative for the Boeing Delegation Option Authorization Organization who has been authorized by the Manager, Seattle ACO, to make such findings. For a repair method to be approved by the Manager, Seattle ACO, as required by this paragraph, the Manager's approval letter must specifically reference this AD. Do the applicable inspection of the repaired area per Part 1 of the Work Instructions of the service bulletin at the applicable time per Part 3 of the Work Instructions of the service bulletin, and repeat the applicable inspection at the applicable interval per Figure 1 of the service bulletin.

(2) If no crack is found, repeat the applicable inspection per paragraph (g) of this AD at the applicable time specified in paragraphs (g)(2)(i) through (g)(2)(iii) of this AD. As an option to the repetitive inspections, accomplishment of paragraph (h)(1) or (h)(2) of this AD, before further flight, extends the threshold for the initiation of the repetitive inspections required by this paragraph.

(i) If the immediately preceding inspection was conducted using an open-hole HFEC inspection method: Conduct the next inspection of that area within 3,000 flight cycles of the last inspection.

(ii) If the immediately preceding inspection was conducted using a surface HFEC inspection method at stations 340 through 420 inclusive and station 500: Conduct the next inspection of that area within 750 flight cycles of the last inspection.

(iii) If the immediately preceding inspection was conducted using a surface HFEC inspection method at stations 440 and 520: Conduct the next inspection of that area at the earlier of the times specified in paragraphs (g)(2)(iii)(A) and (g)(2)(iii)(B) of this AD, and thereafter at intervals not to exceed 250 flight cycles.

(A) Within 750 flight cycles since the last surface HFEC inspection required by paragraph (g) of this AD.

(B) Within 250 flight cycles after the effective date of this AD.

Optional Repair/Modification

(h) For areas on which the inspection required by paragraph (g) of this AD is done per Part 1 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001, or Revision 1, dated March 10, 2005; and on which no cracking is found: Accomplishment of the actions specified in either paragraph (h)(1) or (h)(2) of this AD extends the threshold for the initiation of the repetitive inspections required by paragraph (g)(2) of this AD. For areas on which the inspection required by paragraph (g) of this AD is done per Part 2 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001, or Revision 1, dated March 10, 2005; and on which no cracking is found: Accomplishment of the actions specified in paragraph (h)(1) of this AD extends the threshold for the initiation of the repetitive inspections required by paragraph (g)(2) of this AD.

(1) Do the applicable repair per Part 3 of the Work Instructions of the service bulletin, except as provided by paragraph (j) of this AD. At the applicable time specified in Table 1 of Part 3 of the Work Instructions of the service bulletin, do the applicable inspection of the repaired area per Part 1 of the Work Instructions of the service bulletin. Repeat the inspection thereafter within the applicable interval of 3,000 flight cycles per Figure 1 of the service bulletin.

(2) Do the modification of the attachment hole of the floor panel per Figure 5 of the service bulletin, except as provided by paragraph (j) of this AD. Within 10,000 flight cycles after accomplishment of the modification, do the inspection of the modified area per Part 1 of the Work Instructions of the service bulletin. Repeat the inspection thereafter within the applicable interval of 3,000 flight cycles per Figure 1 of the service bulletin.

New Requirements of This AD

Determining the Number of Flight Cycles for Compliance Time

(i) For the purposes of calculating the compliance threshold and repetitive intervals for actions required by paragraphs (f), (g), or (h) of this AD: As of the effective date of this AD, all flight cycles, including the number of flight cycles in which cabin differential pressure is at 2.0 pounds per square inch (psi) or less, must be counted when determining the number of flight cycles that have occurred on the airplane.

New Revision of Service Bulletin

(j) As of the effective date of this AD, use only the service bulletin specified in Table 1 of this AD.

Table 1.—Service Information

Do—	In accordance with—
(1) The actions required by paragraph (g) of this AD	Parts 1 and 2 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, Revision 1, dated March 10,2005; as applicable.
(2) The applicable inspection of the repaired area required by paragraph (g)(1) of this AD	Parts 1 and 6 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, Revision 1, dated March 10, 2005; as applicable; at the applicable time per Table 1 of Part 3 of the Work Instructions of the service bulletin.
(3) The actions required by paragraph (h)(1) of this AD	Parts 1, 3, and 6 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, Revision 1, dated March 10, 2005; as applicable.
(4) The actions required by paragraph (h)(2) of this AD	Figure 5 and Part 1 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, Revision 1, dated March 10, 2005; as applicable.

No Reporting Requirement

(k) Although the service bulletin referenced in this AD specifies to submit certain information to the manufacturer, this AD does not include that requirement.

Alternative Methods of Compliance (AMOCs)

(l)(1) The Manager, Seattle Aircraft Certification Office (SACO), FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

(2) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD, if it is approved by an Authorized Representative for the Boeing Delegation Option Authorization Organization who 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.

(3) AMOCs approved previously according to AD 2004-03-11 are approved as AMOCs for the corresponding provisions of paragraphs (f) through (h) of this AD.

(4) Before using any AMOC approved in accordance with § 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office.

Material Incorporated by Reference

(m) You must use Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001; or Boeing Alert Service Bulletin 747-53A2439, Revision 1, dated March 10, 2005; as applicable; to perform the actions that are required by this AD, unless the AD specifies otherwise.

(1) The Director of the Federal Register approved the incorporation by reference of Boeing Alert Service Bulletin 747-53A2439, Revision 1, dated March 10, 2005, in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.

(2) On March 15, 2004 (69 FR 5920, February 9, 2004), the Director of the Federal Register approved the incorporation by reference of Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001.

(3) Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for a copy of this service information. You may review copies at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Room PL-401, Nassif Building, Washington, DC; on the Internet at http://dms.dot.gov;​; or at the National Archives and Records Administration (NARA).

For information on the availability of this material at the NARA, call [phone], or go to http://www.archives.gov/​federal_​register/​code_​of_​federal_​regulations/​ibr_​locations.html.

Issued in Renton, Washington, on March 31, 2006.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.