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Proposed Rule

Airworthiness Directives; Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, and 747SR Series Airplanes

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Information about this document as published in the Federal Register.

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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) that applies to all Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, and 747SR series airplanes. The existing AD currently requires repetitive inspections to find cracking of the web, strap, inner chords, and inner chord angle of the forward edge frame of the number 5 main entry door cutouts, and repair, if necessary. This proposed AD would expand the inspection areas to include the frame segment between stringers 16 and 23. This proposed AD would reinstate the repetitive inspections specified above for certain airplanes. This proposed AD would also require repetitive inspections for cracking of repairs. This proposed AD results from additional reports of cracks that have been found in the strap and inner chord of the forward edge frame of the number 5 main entry door cutouts, between stringers 16 and 23. We are proposing this AD to detect and correct such cracks. This condition, if not corrected, could cause damage to the adjacent body structure, which could result in depressurization of the airplane in flight.

DATES:

We must receive comments on this proposed AD by January 4, 2010.

ADDRESSES:

You may send comments by any of the following methods:

  • Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
  • Fax: 202-493-2251.
  • 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: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this proposed AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-544-5000, extension 1; fax 206-766-5680; e-mail me.boecom@boeing.com; 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 or 425-227-1152.

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 (telephone 800-647-5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

Start Further Info

FOR FURTHER INFORMATION CONTACT:

Ivan Li, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6437; fax (425) 917-6590.

End Further Info End Preamble Start Supplemental Information

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-2009-1069; Directorate Identifier 2009-NM-036-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 July 26, 2001, we issued AD 2001-16-02, amendment 39-12370 (66 FR 41440, August 8, 2001), for certain Boeing Model 747 series airplanes. That AD requires repetitive inspections to find cracking of the web, strap, inner chords, and inner chord angle of the forward edge frame of the number 5 main entry door cutouts, and repair, if necessary. That AD resulted from reports of cracks in the web, strap, inner chords, and inner chord angle of the forward edge frame of the number 5 main entry door cutouts. We issued that AD to detect and correct such cracks, which could result in severing of the frame, inability of the frame to react loads from the door stops, and consequent rapid depressurization of the airplane in flight.

Actions Since Existing AD Was Issued

Since we issued AD 2001-16-02, Boeing stated that production line numbers 1305 and on have an improved frame design and issued Boeing Service Bulletin 747-53A2450, Revision 3, dated July 24, 2003, which removed those line numbers from the effectivity. We referred to Boeing Alert Service Bulletin 747-53A2450, Revision 2, including Appendix A, dated January 4, 2001, as the appropriate source of service information for accomplishing the required actions of AD 2001-16-02. Based on Revision 3 of the service bulletin, we approved an alternative Start Printed Page 60216method of compliance (AMOC), dated September 22, 2003, which allowed an alternative applicability to AD 2001-16-02. AD 2001-16-02 is applicable to all Model 747 airplanes except Model 747SP series airplanes; the AMOC allowed an alternative applicability of Model 747 airplanes, production line numbers 1 through 1304, excluding Model 747SP airplanes.

After approving the AMOC, we have since received reports of cracks in the left and right Station 2231 frame inner chord and strap between stringers 16 and 23. Subsequently, we have determined that line numbers 1305 and on are again subject to the unsafe condition.

Relevant Service Information

We have reviewed Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009. Revision 5 of the service bulletin also adds airplanes having production line numbers 1305 and on to the effectivity. Revision 5 describes the same repetitive inspections as those specified in Revision 2 of the service bulletin but it also identifies expanded inspection areas that include the frame segment between stringers 16 and 23.

Revision 5 also specifies repetitive post-repair inspections of the repaired frame segments for cracks and repair if necessary. The post-repair inspections include a detailed inspection, an open hole high frequency eddy current (HFEC) inspection, a surface HFEC inspection, and a subsurface low frequency eddy current inspection, and corrective actions if necessary.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to develop on other airplanes of the same type design. For this reason, we are proposing this AD, which would supersede AD 2001-16-02 and would retain the requirements of the existing AD. This proposed AD would also require accomplishing the actions specified in Relevant Service Information described previously, except as discussed under “Differences Between the Proposed AD and Relevant Service Information.”

Difference Between the Proposed AD and Relevant Service Information

The service bulletin 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:

  • 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 Commercial Airplanes Delegation Option Authorization Organization whom we have authorized to make those findings.

Change to Existing AD

This proposed AD would retain all requirements of AD 2001-16-02. Since AD 2001-16-02 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 2001-16-02Corresponding requirement in this proposed AD
paragraph (a)paragraph (g)
paragraph (b)paragraph (h)
paragraph (c)paragraph (i)

Boeing Commercial Airplanes has received a Delegation Option Authorization (DOA). In paragraph (l) of this AD, we have referred to paragraph (m) of this AD to delegate the authority to approve an alternative method of compliance for any repair required by this AD to an Authorized Representative for the Boeing Commercial Airplanes DOA rather than a Designated Engineering Representative (DER).

Costs of Compliance

There are about 163 airplanes of the affected design in the worldwide fleet. The following table provides the estimated costs for U.S. operators to comply with this proposed AD.

Estimated Costs

ActionWork hoursAverage labor rate per hourPartsCost per airplaneNumber of U.S.-registered airplanesFleet cost
Inspections (required by AD 2001-16-02)16$80None$1,280, per inspection cycle163$208,640, per inspection cycle.
Inspections (new proposed action)28 depending on airplane configuration80NoneUp to $2,240, per inspection cycle; depending on airplane configuration163Up to $365,120, per inspection cycle; depending on airplane configuration.

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 Start Printed Page 60217under the criteria of the Regulatory Flexibility Act.

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

Start List of Subjects

List of Subjects in 14 CFR Part 39

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The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

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PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Start Authority

Authority: 49 U.S.C. 106(g), 40113, 44701.

End Authority
[Amended]

2. The FAA amends § 39.13 by removing amendment 39-12370 (66 FR 41440, August 8, 2001) and adding the following new AD:

Boeing: Docket No. FAA-2009-1069; Directorate Identifier 2009-NM-036-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by January 4, 2010.

Affected ADs

(b) This AD supersedes AD 2001-16-02.

Applicability

(c) This AD applies to Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, and 747SR series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009.

Subject

(d) Air Transport Association (ATA) of America Code 53: Fuselage.

Unsafe Condition

(e) This AD results from additional reports of cracks that have been found in the strap and inner chord of the forward edge frame of the number 5 main entry door cutouts, between stringers 16 and 23. Based on these reports, we have determined that the frame segment between stringers 16 and 23 is also susceptible to the unsafe condition. The Federal Aviation Administration is issuing this AD to detect and correct such cracks. This condition, if not corrected, could cause damage to the adjacent body structure, which could result in depressurization of the airplane in flight.

Compliance

(f) 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 AD 2001-16-02, With New Service Information

Repetitive Inspections for Frame Segment Between Stringers 23 and 31 (No Terminating Action)

(g) For airplanes having line numbers 1 through 1304 inclusive: Inspect the airplane for cracks between stringers 23 and 31 per Boeing Alert Service Bulletin 747-53A2450, Revision 2, including Appendix A, dated January 4, 2001; or Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009; at the later of the times specified in either paragraph (h) or (i) of this AD, per Table 1, as follows. After the effective date of this AD, use only Revision 5 of Boeing Service Bulletin 747-53A2450.

Table 1—Inspection Requirements

Type of inspectionArea to inspect
(1) Detailed VisualStrap inner chords forward and aft of the web, and exposed web adjacent to the inner chords on station 2231 frame from stringer 23 through 31 per Figure 5 or Figure 6 of the service bulletin, as applicable.
(2) Surface High Frequency Eddy Current (HFEC)Station 2231 inner chord angles at lower main sill interface per Figure 5 or Figure 6 of the service bulletin, as applicable.
(3) Open Hole HFECStation 2231 frame fastener locations per Figures 4 and 7, and either Figure 5 or 6 of the service bulletin, as applicable.
(4) Surface HFECAround fastener locations on station 2231 inner chords from stringer 23 through 31 per Figure 5 or Figure 6 of the service bulletin, as applicable.
(5) Low Frequency Eddy CurrentStation 2231 frame strap in areas covered by the reveal per Figure 5 or Figure 6 of the service bulletin, as applicable.

(h) Do the inspections specified in paragraph (g) of this AD at the applicable times specified in paragraph (h)(1) or (h)(2) of this AD. Repeat the inspections at intervals not to exceed 3,000 flight cycles.

(1) Do the inspections per Table 1 of this AD at the applicable time specified in the logic diagram in Figure 1 of Boeing Alert Service Bulletin 747-53A2450, Revision 2, including Appendix A, dated January 4, 2001. Where the compliance time in the logic diagram specifies a compliance time beginning, “from receipt of this service bulletin,” this AD requires that the compliance time begin “after September 12, 2001 (the effective date of AD 2001-16-02).”

(2) After the effective date of this AD, do the inspections per Table 1 of this AD at the applicable compliance time specified in paragraph 1.E., “Compliance” of the Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009. Where the compliance time in the service bulletin specifies a compliance time beginning, “after the date on Revision 2 of this service bulletin,” this AD requires that the compliance time begin “after September 12, 2001 (the effective date of AD 2001-16-02).”

(i) Within 3,000 flight cycles after accomplishment of the inspections specified in Figure 1 of Boeing Alert Service Bulletin 747-53A2450, dated May 4, 2000, or Revision 1, dated July 6, 2000, repeat the inspections at intervals not to exceed 3,000 flight cycles.

Note 1:

There is no terminating action currently available for the inspections required by paragraph (g) of this AD.

Note 2:

Where there are differences between the AD and the alert service bulletin, the AD prevails.

New Requirements of This AD

Additional Repetitive Inspections (For Frame Segment Between Stringers 16 and 23)

(j) For all airplanes: Before the accumulation of 16,000 total flight cycles, or within 1,500 flight cycles after the effective date of this AD, whichever occurs later, do a detailed inspection, an open hole high frequency eddy current (HFEC) inspection, a surface HFEC inspection, and a subsurface low frequency eddy current (LFEC) inspection for cracking of the forward edge frame of the number 5 main entry door cutouts, at station 2231, between stringers 16 and 23; in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009. Repeat the inspections thereafter at intervals not to exceed 3,000 flight cycles.

Repetitive Inspections for Line Numbers 1305 and On (For Frame Segment Between Stringers 23 and 31)

(k) For airplanes having line numbers 1305 and on: Before 16,000 total flight cycles or within 1,500 flight cycles after the effective date of this AD, whichever occurs later, do a detailed inspection, an open hole HFEC inspection, a surface HFEC inspection, and a Start Printed Page 60218subsurface LFEC inspection for cracking of the forward edge frame of the number 5 main entry door cutouts, at station 2231, between stringers 23 and 31; in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009. Repeat the inspections thereafter at intervals not to exceed 3,000 flight cycles.

Corrective Action

(l) If any crack is found during any inspection required this AD, before further flight repair the crack per a method approved by the Manager, Seattle Aircraft Certification Office (SACO), FAA; Per data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative who has been authorized by the Manager, Seattle ACO, to make such findings; or in accordance with Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009. 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. As of the effective date of this AD, repair the crack using a method approved in accordance with the procedures specified in paragraph (o) of this AD.

Post-Repair Inspections

(m) Except as required by paragraph (n) of this AD, for airplanes on which the forward edge frame of the number 5 main entry door cutouts, at station 2231, between stringers 16 and 31, is repaired in accordance with Boeing Alert Service Bulletin 747-53A2450: Within 3,000 flight cycles after doing the repair or within 1,500 flight cycles after the effective date of this AD, whichever occurs later, do the detailed, LFEC, and HFEC inspections of the repaired area for cracks in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009. If no cracking is found, repeat the inspections thereafter at intervals not to exceed 3,000 flight cycles. If any crack is found, before further flight, repair using a method approved in accordance with the procedures specified in paragraph (o) of this AD. Doing the inspections specified in paragraph (m) of this AD terminates the repetitive inspections required by paragraphs (g), (h), (i), (j), and (k) of this AD for the repaired area.

(n) For any frame that is repaired in accordance with a method other than the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 29, 2009, do the inspection in accordance with a method approved in accordance with the procedures specified in paragraph (o) of this AD.

Alternative Methods of Compliance (AMOCs)

(o)(1) The Manager, Seattle Aircraft Certification Office (SACO), FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Ivan Li, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6437; fax (425) 917-6590; Or, e-mail information to 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.

(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD.

(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 an Authorized Representative for the Boeing Commercial Airplanes 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.

(4) AMOCs approved previously in accordance with AD 2001-16-02, amendment 39-12370, are approved as AMOCs for the corresponding provisions of paragraphs (g), (h), (i), and (l) of this AD.

Start Signature

Issued in Renton, Washington, on November 6, 2009.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.

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[FR Doc. E9-27963 Filed 11-19-09; 8:45 am]

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