05-7155. Airworthiness Directives; Boeing Model 747-100, -100B, -100B SUD, -200B, and -300 Series Airplanes; and Model 747SP and 747SR Series Airplanes

AGENCY:

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

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to supersede an existing airworthiness directive (AD) for certain Boeing Model 747 series airplanes. That AD currently requires repetitive inspections to detect cracks in various areas of the fuselage internal structure, and repair if necessary. This proposed AD would require repetitive inspections of additional areas of the fuselage internal structure, and related investigative/corrective actions if necessary. This proposed AD also would remove certain requirements from the existing AD. This proposed AD is prompted by the results of fatigue testing of the fuselage structure of a Boeing Model 747SR series airplane. We are proposing this AD to prevent the loss of the structural integrity of the fuselage, which could result in rapid depressurization of the airplane.

DATES:

We must receive comments on this proposed AD by May 26, 2005.

ADDRESSES:

Use one of the following addresses to submit comments on this proposed AD.

• DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
• Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street SW, Nassif Building, room PL-401, Washington, DC 20590.

Fax: [phone].

• Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street SW, Washington, DC, 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 Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207.

You can examine the contents of this 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, room PL-401, on the plaza level of the Nassif Building, Washington, DC. This docket number is FAA-2005-20880; the directorate identifier for this docket is 2003-NM-229-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:

Comments Invited

We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2005-20880; Directorate Identifier 2003-NM-229-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

We will post all comments we receive, without change, to http://dms.dot.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of our docket web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov.

Examining the Docket

You can examine the AD docket 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 DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the DMS receives them.

Discussion

On May 14, 2002, we issued AD 2002-10-10, amendment 39-12756 (67 FR 36081, May 23, 2002), for certain Boeing Model 747 series airplanes. That AD requires repetitive inspections to detect cracking in various areas of the fuselage internal structure, and repair if necessary. That AD was prompted by the results of fatigue testing that revealed severed upper chords of the upper deck floor beams due to fatigue cracking. We issued that AD to prevent loss of the structural integrity of the fuselage, which could result in rapid depressurization of the airplane.

Actions Since Existing AD Was Issued

Since we issued AD 2002-10-10, the manufacturer reported that cracking was found on the fatigue test airplane in areas not included in Boeing Service Bulletin 747-53-2349, dated June 27, 1991; or Boeing Alert Service Bulletin 747-53A2349, Revision 1, dated October 12, 2000. (Those service bulletins were referenced as the appropriate sources of service information in AD 2002-10-10.) The new areas are the fuselage skin at all four corners of the main electronics bay access door cutout, and certain nose wheel well (NWW) sidewall panels and stiffeners, and certain main deck floor beams at the NWW vertical beams.

Relevant Service Information

We have reviewed Boeing Service Bulletin 747-53A2349, Revision 2, dated April 3, 2003. The service bulletin describes procedures that are essentially the same as the procedures in Boeing Alert Service Bulletin 747-53A2349, Revision 1. Revision 2 includes a new inspection area, Area 9. Area 9 includes the fuselage skin at all four corners of the main electronics bay access door cutout. Revision 2 also includes additional inspections in Area 7. Area 7 now includes certain NWW sidewall panels and stiffeners between STA 340 and STA 400, and the STA 360 and 380 main deck floor beams at the NWW vertical beams. The actions described in Revision 2 also affect Area 1. Among other things, for Group 3 airplanes only, Area 1 has also been redefined.

For airplanes on which any cracking is found, Revision 2 references the Boeing 747 Structural Repair Manual for repair instructions. For airplanes with damage that is beyond the limits specified in the service bulletin, the service bulletin specifies contacting Boeing for repair data.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other products of this same type design. Therefore, we are proposing this AD, which would supersede AD 2002-10-10. This proposed AD would continue to require repetitive inspections to detect cracks in various areas of the fuselage internal structure, and repair if necessary. This proposed AD would also require repetitive inspections of additional areas of the fuselage internal structure, and related investigative/corrective actions if necessary. This proposed AD also would remove all requirements related to the upper deck floor beams from the existing AD, as discussed below under “Other Related Rulemaking.” This proposed AD would require you to use the service information described previously to perform these actions, except as discussed under “Differences Between the Proposed AD and Service Information.”

Other Related Rulemaking

Operators should note that we plan to issue a separate AD rulemaking action (reference Directorate Identifier 2004-NM-55-AD) to address the identified unsafe condition as it relates to the upper deck floor beams. Therefore, all requirements from AD 2002-10-10 that relate to the upper deck floor beams are in that separate AD rulemaking action.

Differences Between the Proposed AD and Service Information

The service bulletin specifies that you may contact the manufacturer for instructions on how to repair certain conditions, but this proposed AD would require you to repair those conditions in one of the following ways:

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

Change to Existing AD

This proposed AD would retain certain requirements of AD 2002-10-10. Since AD 2002-10-10 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 2002-10-10	Corresponding requirement in this proposed AD
Paragraph (a)	Paragraph (f).
Paragraph (b)	Paragraph (g).
Paragraph (c)	Paragraph (h).

Costs of Compliance

This proposed AD would affect about 489 airplanes worldwide, and 155 airplanes of U.S. registry. The following table provides the estimated costs for U.S. operators to comply with this proposed AD.

Estimated Costs

Action	Work hours	Average labor rate per hour	Parts	Cost per airplane, per inspection cycle	Number of U.S. registered airplanes	Fleet cost
Inspections, excluding upper deck floor beams, per inspection cycle (required by AD 2002-10-10)	145	$65	None	$9,425	155	$1,460,875
Inspections (new proposed AD)	130	65	None	8,450	155	1,309,750

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); 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 proposed 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
• 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 amendment 39-12756 (67 FR 36081, May 23, 2002) and adding the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2005-20880; Directorate Identifier 2003-NM-229-AD.

Comments Due Date

(a) The Federal Aviation Administration must receive comments on this airworthiness directive (AD) action by May 26, 2005.

Affected ADs

(b) This AD supersedes AD 2002-10-10, amendment 39-12756 (67 FR 36081, May 23, 2002).

Applicability

(c) This AD applies to Boeing Model 747-100, -100B, -100B SUD, -200B, and -300 series airplanes; and Model 747SP and 747SR series airplanes; certificated in any category; identified in Boeing Service Bulletin 747-53A2349, Revision 2, dated April 3, 2003.

Unsafe Condition

(d) This AD was prompted by the results of fatigue testing of the fuselage structure of a Boeing Model 747SR series airplane. We are issuing this AD to prevent the loss of the structural integrity of the fuselage, which could result in rapid depressurization 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 2002-10-10 (Excluding Upper Deck Floor Beams)

Repetitive Inspections

(f) Prior to the accumulation of 22,000 total flight cycles, or within 1,000 flight cycles after June 11, 1993 (the effective date of AD 93-08-12, amendment 39-8559), whichever occurs later, unless accomplished previously within the last 2,000 flight cycles; and thereafter at intervals not to exceed 3,000 flight cycles: Perform an internal detailed inspection to detect cracks in the areas of the fuselage internal structure specified in paragraphs (f)(1) through (f)(6) of this AD; in accordance with Boeing Service Bulletin 747-53-2349, dated June 27, 1991; Boeing Alert Service Bulletin 747-53A2349, Revision 1, dated October 12, 2000; or Boeing Service Bulletin 747-53A2349, Revision 2, dated April 3, 2003. After the effective date of this AD, only Revision 2 of Boeing Service Bulletin 747-53A2349 may be used. Continue doing the inspections until the inspections required by paragraph (i) of this AD are done.

(1) Section 42 upper lobe frames.

(2) Section 46 lower lobe frames.

(3) Section 42 lower lobe frames.

(4) Main entry door cutouts.

(5) Section 41 body station 260, 340, and 400 bulkheads.

(6) Main entry doors.

Note 1:

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.”

(g) Prior to the accumulation of 25,000 total flight cycles, or within 1,000 flight cycles after June 11, 1993, whichever is later, unless already done within the last 2,000 flight cycles; and thereafter at intervals not to exceed 3,000 flight cycles: Do an internal detailed inspection to detect cracks in the Section 46 upper lobe frames, in accordance with Boeing Service Bulletin 747-53-2349, dated June 27, 1991; Boeing Alert Service Bulletin 747-53A2349, Revision 1, dated October 12, 2000; or Boeing Service Bulletin 747-53A2349, Revision 2, dated April 3, 2003. After the effective date of this AD, only Revision 2 of Boeing Service Bulletin 747-53A2349 may be used.

Repair

(h) Before further flight, repair any cracks detected during the inspections done per paragraph (f) or (g) of this AD, in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or according to data meeting the certification basis of the airplane approved a Boeing Company Designated Engineering Representative (DER) who has been authorized by the Manager, Seattle ACO, to make such findings; or by 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, the approval must specifically reference this AD.

New Requirements of This AD

Repetitive Inspections

(i) Do an internal detailed inspection to detect cracking in the areas of the fuselage internal structure specified in paragraphs (i)(1), (i)(2), (i)(3), and (i)(5) of this AD, and internal and external detailed inspections of the areas specified in paragraphs (i)(4), (i)(6), and (i)(7) of this AD. Do the inspections in accordance with Boeing Service Bulletin 747-53A2349, Revision 2, dated April 3, 2003. Do the inspections at the applicable time specified in paragraph (j) of this AD. Accomplishment of these inspections terminates the requirements of paragraph (f) of this AD.

(1) Section 42 upper lobe frames.

(2) Section 46 lower lobe frames.

(3) Section 42 lower lobe frames.

(4) Main entry door cutouts.

(5) Nose wheel well bulkheads, sidewall panels, and the STA 360 and 380 floor beams. These areas include the Section 41 body station 260, 340, and 400 bulkheads.

(6) Main entry doors.

(7) Main electronics bay access door cutout.

(j) Do the inspections required by paragraph (i) of this AD at the applicable time specified in paragraph (j)(1), (j)(2), or (j)(3) of this AD. Repeat the inspections thereafter at intervals not to exceed 3,000 flight cycles.

(1) For airplanes on which the inspections required by paragraphs (f)(1), (f)(2), (f)(3), (f)(4), and (f)(6) of this AD have been done before the effective date of this AD, but the inspections required by paragraphs (i)(5) and (i)(7) of this AD have not been done: Within 3,000 flight cycles since accomplishment of the most recent inspection required by paragraphs (f)(1), (f)(2), (f)(3), (f)(4), and (f)(6) of this AD.

(2) For airplanes on which the inspections required by paragraphs (i)(5) and (i)(7) have been done before the effective date of this AD: Within 3,000 flight cycles since accomplishment of the most recent inspection required by paragraphs (i)(5) and (i)(7) of this AD, or within 1,000 flight cycles after the effective date of this AD, whichever is later.

(3) For airplanes on which the inspections required by paragraph (f) of this AD have not been done before the effective date of this AD: Prior to the accumulation of 22,000 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever is later.

Repair

(k) Before further flight, repair any cracking found during any inspection required by paragraph (i) of this AD in accordance with Boeing Service Bulletin 747-53A2349, Revision 2, dated April 3, 2003. Where the service bulletin specifies to contact Boeing for repair instructions, 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, and that have been approved by an AR for the Boeing DOA who has been authorized by the FAA to make those findings. For a repair method to be approved by the Manager, Seattle ACO, as required by this paragraph, the approval letter must specifically reference this AD.

Actions Previously Accomplished

(l) Inspections required by paragraph (i) of this AD, accomplished before the effective date of this AD, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-53-2349, dated June 27, 1991; or Boeing Alert Service Bulletin 747-53A2349, Revision 1, dated October 12, 2000; are acceptable for compliance with the corresponding action required by paragraph (i) of this AD.

Alternative Methods of Compliance (AMOCs)

(m)(1) The Manager, Seattle ACO, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19.

(2) Alternative methods of compliance and FAA-approved repairs, approved previously in accordance with AD 2002-10-10 or AD 93-08-12, are approved as alternative methods of compliance with the corresponding requirements of this AD.

Issued in Renton, Washington, on April 1, 2005.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.