05-5388. Airworthiness Directives; Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-300, 747SP, and 747SR 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 747-100, 747-100B, 747-100B SUD, 747-200B, 747-300, 747SP, and 747SR series airplanes. That AD currently requires one-time inspections for cracking in certain upper deck floor beams and follow-on actions. This new AD expands the existing inspection area and requires inspecting fastener holes in certain areas of airplanes modified previously, and taking corrective actions if necessary. This action also defines new sources for instructions for repairs and post-modification/repair inspections. This AD is prompted by reports of fatigue cracking of the upper chord of certain upper deck floor beams. We are issuing this AD to find and fix cracking in certain upper deck floor beams, which could extend and sever floor beams adjacent to the body frame and result in rapid depressurization and loss of controllability of the airplane.

DATES:

This AD becomes effective April 25, 2005.

The incorporation by reference of Boeing Service Bulletin 747-53A2459, Revision 1, dated March 11, 2004, is approved by the Director of the Federal Register as of April 25, 2005.

On October 16, 2002 (67 FR 57510, September 11, 2002), the Director of the Federal Register approved the incorporation by reference of Boeing Alert Service Bulletin 747-53A2459, dated January 11, 2001.

ADDRESSES:

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

Docket: The AD docket contains the proposed AD, comments, and any final disposition. You can examine the 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 U.S. Department of Transportation, 400 Seventh Street, SW., room PL-401, Washington, DC. This docket number is FAA-2004-19535; the directorate identifier for this docket is 2004-NM-78-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:

The FAA proposed to amend part 39 of the Federal Aviation Regulations (14 CFR Part 39) with an AD to supersede AD 2002-18-04, amendment 39-12878 (67 FR 57510, September 11, 2002). The existing AD applies to certain Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-300, 747SP, and 747SR series airplanes. The proposed AD was published in the Federal Register on November 5, 2004 (69 FR 64525), to continue to require one-time inspections for cracking in certain upper deck floor beams and follow-on actions. The proposed AD would expand the existing inspection area, and would require inspecting fastener holes in certain areas of airplanes modified previously, and taking corrective actions if necessary. The proposed AD also would define new sources for instructions for repairs and post-modification/repair inspections.

Comments

We provided the public the opportunity to participate in the development of this AD. We have considered the comments that have been submitted on the proposed AD by a single commenter.

Request To Revise Delegation Language

The commenter requests that we revise the proposed AD to change references to approval of repairs or alternative methods of compliance (AMOCs) by Boeing Company Designated Engineering Representatives (DERs). The commenter states that these provisions should refer to approval by Authorized Representatives (ARs) of the Boeing Delegation Option Authorization (DOA) Organization. The commenter notes that, since the issuance of the proposed AD, Boeing has received a DOA.

We concur. We have revised paragraphs (h)(1)(i), (h)(2), and (i) of this AD (which are restated requirements of AD 2002-18-04) to delegate the authority to approve a repair to a Boeing Company DER or to an AR of the Boeing DOA Organization. We have revised paragraphs (m) and (o)(2) to delegate the authority to approve a repair or an AMOC to an AR of the Boeing DOA.

Request To Revise Note 2 to Acknowledge Terminating Action

The commenter requests that we revise Note 2 of the proposed AD, which states:

There is no terminating action at this time for the repetitive post-modification/repair inspections in accordance with paragraph (i) of this AD, and instructions for those inspections are not provided in the original issue of Boeing Alert Service Bulletin 747-53A2459, dated January 11, 2001.

The commenter notes that paragraph (l) of the proposed AD states that doing the initial inspection required by that paragraph terminates the repetitive inspections required by paragraph (i).

We agree. Note 2 was carried over with the other requirements of AD 2002-18-04. We inadvertently failed to revise the note to reflect the fact that inspecting in accordance with paragraph (l) of this AD terminates the requirements of paragraph (i) of this AD. We have revised Note 2 of this AD to remove the statement that there is no terminating action for the inspections in paragraph (i) of this AD.

Request To Revise Paragraph (j)

The commenter requests that we clarify paragraph (j) of the proposed AD to specify that only the holes not previously inspected in accordance with Boeing Alert Service Bulletin 747-53A2459, dated January 11, 2001, need to be inspected in accordance with that paragraph. The commenter points out that paragraph (g) of the proposed AD requires modifying the upper deck floor beams at STA 340 and STA 360. If this modification is not done at the time of the inspection required by paragraph (f) of the proposed AD, paragraph (g) specifies that the inspection in paragraph (f) must be repeated immediately prior to accomplishing the modification in paragraph (g). The commenter notes that, after the effective date of the AD, this repeat inspection must be accomplished in accordance with Boeing Service Bulletin 747-53A2459, Revision 1, dated March 11, 2004. Thus, paragraph (j) need only require the inspection of holes not previously inspected by the original issue of the service bulletin.

We agree with the commenter's intent, but we find that no change to this AD is necessary to meet the commenter's intent. Paragraph (j) of the proposed AD already specifies doing “* * * inspections for cracking of the fastener holes inboard of the body frame that were not previously inspected on the STA 340 and STA 360 upper deck floor beams.” After further review, however, we have determined that the detailed inspection that would have been required by paragraph (j) of this AD is the same as the one required by paragraph (f) of this AD. Therefore, we have revised paragraph (j) of this AD to remove the requirement to perform a detailed inspection.

The commenter also requests that we allow the inspections required by paragraph (j) of the proposed AD to be accomplished in accordance with Part 6 of the Accomplishment Instructions of Boeing Service Bulletin 747-53A2459, Revision 1. The commenter states no rationale for its request.

We do not concur. We note that the inspections and corrective actions specified in Part 6 of the Accomplishment Instructions of Boeing Service Bulletin 747-53A2459, Revision 1, are applicable only to airplanes modified in accordance with the initial release of Boeing Alert Service Bulletin 747-53A2459. No change to the AD is necessary in this regard.

Request To Revise Paragraph (l)

The commenter requests that we revise paragraph (l) of the proposed AD to acknowledge an equivalent inspection for the purposes of establishing the applicable compliance time for the initial inspection specified in Table 3 of the proposed AD. The commenter states that an inspection in accordance with Part 6, Figure 14, of Boeing Service Bulletin 747-53A2459, Revision 1, is equivalent to an inspection in accordance with Figure 12 of Boeing Service Bulletin 747-53A2459, Revision 1. The commenter states that the same holes are covered by Figure 14 and Figure 12, and the same method is used for the inspection.

We concur, for the reasons stated by the commenter. We have revised paragraph (l) of this AD to specify that, for the purposes of paragraph (l) and Table 3 of this AD, an inspection in accordance with Part 6, Figure 14, of the Accomplishment Instructions of Boeing Service Bulletin 747-53A2459, Revision 1, is equivalent to an inspection in accordance with Part 5, Figure 12, of that service bulletin.

Conclusion

We have carefully reviewed the available data, including the comments that have been submitted, 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

This AD will affect about 433 airplanes worldwide. The following table provides the estimated costs for U.S. operators to comply with this AD.

Estimated Costs

Action	Work hours	Average labor rate per hour	Cost per airplane	Number of U.S.-registered airplanes	Fleet cost
Initial inspections (required by AD 2002-18-04)	8	$65	$520	125	$65,000
Modification/permanent repair (required by AD 2002-18-04)	24	65	1,560	125	195,000
Post-mod/repair inspection (required by AD 2002-18-04)	1 24	65	1 1,560	125	1 195,000
One-time inspection of fastener holes inboard of the body frame (new requirement)	24	65	1,560	N/A	2 1,560
1 Per inspection cycle.
2 Per airplane.

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. 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 FAA amends § 39.13 by removing amendment 39-12878 ( 67 FR 57510, September 11, 2002), and by adding the following new airworthiness directive (AD):

2005-06-12 Boeing: Amendment 39-14020. Docket No. FAA-2004-19535; Directorate Identifier 2004-NM-78-AD.

Effective Date

(a) This AD becomes effective April 25, 2005.

Affected ADs

(b) This AD supersedes AD 2002-18-04, amendment 39-12878.

Applicability

(c) This AD applies to Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-300, 747SP, and 747SR series airplanes; line numbers 1 through 810 inclusive; certificated in any category; and not equipped with a nose cargo door.

Unsafe Condition

(d) This AD was prompted by reports of fatigue cracking of the upper chord of certain upper deck floor beams. We are issuing this AD to find and fix cracking in certain upper deck floor beams, which could extend and sever floor beams adjacent to the body frame and result in rapid depressurization 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.

Requirements of AD 2002-18-04

Inspections

(f) At the compliance time specified in paragraph (f)(1) or (f)(2) of this AD, as applicable, perform one-time detailed and open-hole high-frequency eddy current (HFEC) inspections for cracking in the upper deck floor beams at station (STA) 340 and STA 360, in accordance with Boeing Alert Service Bulletin 747-53A2459, dated January 11, 2001; or Boeing Service Bulletin 747-53A2459, Revision 1, dated March 11, 2004. As of the effective date of this AD, only Revision 1 may be used. For the purposes of this AD, flight cycles with a cabin differential pressure of 2.0 psi or less are not calculated into the compliance thresholds specified in this AD. However, all cabin pressure records must be maintained for each airplane, and no fleet averaging of cabin pressure is allowed.

Note 1:

For the purposes of this AD, a detailed inspection is: “An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required.”

(1) For airplanes with 22,000 or fewer total flight cycles as of October 16, 2002 (the effective date of AD 2002-18-04): Do the inspections prior to the accumulation of 16,000 total flight cycles, or within 1,500 flight cycles after October 16, 2002, whichever is later.

(2) For airplanes with more than 22,000 total flight cycles as of the effective date of this AD: Do the inspections within 500 flight cycles after October 16, 2002.

Modification

(g) If no crack is found during the inspections in accordance with paragraph (f) of this AD: Within 5,000 flight cycles after the initial inspections, modify the upper deck floor beams at STA 340 and STA 360, in accordance with Boeing Alert Service Bulletin 747-53A2459, dated January 11, 2001; or Boeing Service Bulletin 747-53A2459, Revision 1, dated March 11, 2004. As of the effective date of this AD, only Revision 1 may be used. If this modification is not done before further flight after the inspections required by paragraph (f) of this AD, those inspections must be repeated one time, immediately before accomplishing the modification in this paragraph. If any crack is found during these repeat inspections, before further flight, accomplish paragraph (h)(2) of this AD.

Repair

(h) If any crack is found during the inspections in accordance with paragraph (f) of this AD: Before further flight, repair in accordance with either paragraph (h)(1) or (h)(2) of this AD.

(1) Accomplish repairs in accordance with paragraphs (h)(1)(i) and (h)(1)(ii) of this AD.

(i) Accomplish a time-limited repair (including removing certain fasteners and the existing strap, performing open-hole HFEC inspections of the chord and web, stop-drilling web cracks, replacing the outboard section of the web, if applicable, and installing new straps) in accordance with Boeing Alert Service Bulletin 747-53A2459, dated January 11, 2001; or Boeing Service Bulletin 747-53A2459, Revision 1, dated March 11, 2004; except where the service bulletin specifies to contact Boeing for appropriate action, repair in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or in accordance with data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative (DER), or an Authorized Representative (AR) for the Boeing Delegation Option Authorization (DOA) Organization, who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved as required by this paragraph, the approval must specifically reference this AD. As of the effective date of this AD, only Revision 1 of the service bulletin may be used.

(ii) Within 18 months or 1,500 flight cycles after installation of the time-limited repair in accordance with paragraph (h)(1)(i) of this AD, whichever is first, do paragraph (h)(2) of this AD.

(2) Accomplish a permanent repair in accordance with Boeing Alert Service Bulletin 747-53A2459, dated January 11, 2001; or Boeing Service Bulletin 747-53A2459, Revision 1, dated March 11, 2004; except where the service bulletin specifies to contact Boeing for appropriate action, 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 a Boeing Company DER, or an AR for the Boeing DOA Organization, who has been authorized by the Manager, Seattle ACO, to make such findings. For a repair method to be approved as required by this paragraph, the approval must specifically reference this AD. As of the effective date of this AD, only Revision 1 of the service bulletin may be used.

Repetitive Inspections: Post-Modification/Repair

(i) Within 15,000 flight cycles after modification of the upper deck floor beams in accordance with paragraph (g) of this AD, or after permanent repair of the upper deck floor beams in accordance with paragraph (h) of this AD, as applicable: Perform either open-hole HFEC inspections for cracking of fastener holes common to the upper chord, reinforcement straps, and the body frame; or surface HFEC inspections for cracking along the lower edge of the upper chord of the floor beam at the intersection with the body frame; and repeat these inspections at the interval specified in paragraph (i)(1) or (i)(2) of this AD, as applicable, until the initial inspection required by paragraph (l) of this AD is complete. Perform these inspections and repair any cracking found during these inspections 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 a Boeing Company DER, or an AR for the Boeing DOA Organization, who has been authorized by the Manager, Seattle ACO, to make such findings. For an inspection or repair method to be approved as required by this paragraph, the approval must specifically reference this AD.

(1) If the most recent inspection used the surface HFEC method: Repeat the inspection within 1,000 flight cycles.

(2) If the most recent inspection used the open-hole HFEC method: Repeat the inspection every 3,000 flight cycles.

Note 2:

Instructions for post-modification/repair inspections are not provided in the original issue of Boeing Alert Service Bulletin 747-53A2459, dated January 11, 2001.

New Requirements of This AD

One-Time Inspection for Airplanes Inspected Previously

(j) For airplanes on which the inspection in paragraph (f) of this AD has been done prior to the effective date of this AD in accordance with Boeing Alert Service Bulletin 747-53A2459, dated January 11, 2001, but the modification specified in paragraph (g) or the permanent repair specified in paragraph (h) of this AD has not been done: At the applicable time specified in Table 1 of this AD, do a one-time open-hole HFEC inspection for cracking of the fastener holes inboard of the body frame that were not previously inspected on the STA 340 and STA 360 upper deck floor beams. Do this inspection in accordance with Part 1 of the Accomplishment Instructions of Boeing Service Bulletin 747-53A2459, Revision 1, dated March 11, 2004.

Table 1.—Compliance Times for Paragraph (j)

Total number of accumulated flight cycles as of the effective date of this AD	Compliance time
22,000 or fewer	Within 5,000 flight cycles after the initial open-hole HFEC inspection for cracking in accordance with paragraph (f) of this AD, or within 1,000 flight cycles after the effective date of this AD, whichever is later.
22,001 or more	Prior to the accumulation of 25,000 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever is later.

One-Time Inspection for Airplanes Modified/Repaired Previously

(k) For airplanes on which the modification specified in paragraph (g) or the permanent repair specified in paragraph (h) of this AD has been done prior to the effective date of this AD in accordance with Boeing Alert Service Bulletin 747-53A2459, dated January 11, 2001: At the applicable time specified in Table 2 of this AD, do a one-time open-hole HFEC inspection for cracking of fastener holes common to the modification straps, in accordance with Part 6 of the Accomplishment Instructions of Boeing Service Bulletin 747-53A2459, Revision 1, dated March 11, 2004.

Table 2.—Compliance Times for Paragraph (k)

Total number of accumulated flight cycles when the modification or permanent repair was done	Compliance time
22,000 or fewer	Within 3,000 flight cycles after doing the modification or permanent repair, or 1,000 flight cycles after the effective date of this AD, whichever is later.
22,001 or more	Within 1,500 flight cycles after doing the modification or permanent repair, or 1,000 flight cycles after the effective date of this AD, whichever is later.

Repetitive Inspections: Post-Modification/Repair

(l) Do open-hole HFEC inspections for cracking of the STA 340 and STA 360 upper deck floor beams at fastener holes common to the upper chord, reinforcement straps, and body frame; or do surface HFEC inspections for cracking along the lower edge of the upper chord and reinforcement straps of the floor beams. Do the applicable inspection in accordance with Part 5 of the Accomplishment Instructions of Boeing Service Bulletin 747-53A2459, Revision 1, dated March 11, 2004. Do the initial inspections at the applicable times specified in Table 3 of this AD, and repeat the inspection at the applicable interval specified in Figure 9 of the service bulletin. Completing the initial inspection required by this paragraph terminates the repetitive inspections required by paragraph (i) of this AD. For airplanes on which paragraph (i) of this AD has not been done, doing the initial inspection required by this paragraph at the specified compliance time eliminates the need to comply with paragraph (i) of this AD. For the purposes of this paragraph and Table 3 of this AD, an inspection in accordance with Part 6, Figure 14, of the Accomplishment Instructions of Boeing Service Bulletin 747-53A2459, Revision 1, is equivalent to an inspection in accordance with Part 5, Figure 12, of the Accomplishment Instructions of Boeing Service Bulletin 747-53A2459, Revision 1.

Table 3.—Compliance Times for Initial Inspection Required By Paragraph(l)

For the inspections identified in the following figures referenced in Figure 9 of the service bulletin—	For these airplanes—	Do the inspection—
Figure 10 or 11	Airplanes not inspected previously in accordance with paragraph (i) of this AD	Within 15,000 flight cycles after doing the modification or permanent repair.
Figure 10 or 11	Airplanes inspected previously in accordance with paragraph (i) of this AD using the surface HFEC method for the most recent inspection	Within 1,000 flight cycles after the most recent inspection.
Figure 10 or 11	Airplanes inspected previously in accordance with paragraph (i) of this AD using the open-hole HFEC method for the most recent inspection	Within 3,000 flight cycles after the most recent inspection.
Figure 12 or 13	All airplanes	Within 6,000 flight cycles after doing the modification or permanent repair, or within 1,000 flight cycles after the effective date of this AD, whichever is later.

Repair

(m) If any crack is found during any inspection required by paragraph (j), (k), or (l) of this AD: Before further flight, repair in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-53A2459, Revision 1, dated March 11, 2004; except where the service bulletin specifies to contact Boeing for appropriate action, 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 an AR for the Boeing DOA Organization who has been authorized by the Manager, Seattle ACO, to make such findings. For a repair method to be approved, the approval must specifically reference this AD.

Reporting Not Required

(n) Although Boeing Service Bulletin 747-53A2459, Revision 1, dated March 11, 2004, specifies to report certain body frame cracks on certain airplanes, this AD does not include that requirement.

Alternative Methods of Compliance (AMOCs)

(o)(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.

(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 AR for the Boeing DOA Organization who has been authorized by the Manager, Seattle ACO, to make such findings.

(3) AMOCs approved previously in accordance with AD 2002-18-04 are approved as alternative methods of compliance with paragraphs (f), (g), (h), and (i) of this AD.

Material Incorporated by Reference

(p) You must use Boeing Alert Service Bulletin 747-53A2459, dated January 11, 2001; or Boeing Service Bulletin 747-53A2459, Revision 1, dated March 11, 2004; to perform the actions that are required by this AD, unless the AD specifies otherwise.

(1) The Director of the Federal Register approves the incorporation by reference of Boeing Service Bulletin 747-53A2459, Revision 1, dated March 11, 2004, in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.

(2) The Director of the Federal Register previously approved the incorporation by reference of Boeing Alert Service Bulletin 747-53A2459, dated January 11, 2001, as of October 16, 2002 (67 FR 57510, September 11, 2002).

(3) The Director of the Federal Register approves the incorporation by reference of these documents in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. For copies of the service information, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. For information on the availability of this material at the National Archives and Records Administration (NARA), call [phone], or go to http://www.archives.gov/​federal_​register/​code_​of_​federal_​regulations/​ibr_​locations.html. You may view the AD docket at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW, room PL-401, Nassif Building, Washington, DC.

Issued in Renton, Washington, on March 9, 2005.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.