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Proposed Rule

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

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble

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 certain Boeing Model 747-200C and -200F series airplanes. The existing 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 proposed AD would reduce the compliance time for all initial inspections and reduce the repetitive interval for a certain inspection. This proposed AD is prompted by new reports of cracks in the upper deck floor beams occurring at lower flight cycles. We are proposing 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:

We must receive comments on this proposed AD by October 31, 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: (202) 493-2251.
  • 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 Airplanes, 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-2005-22423; the directorate identifier for this docket is 2005-NM-068-AD.

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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 (425) 917-6437; fax (425) 917-6590.

End Further Info End Preamble Start Supplemental Information

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-2005-22423; Directorate Identifier 2005-NM-068-AD” at the beginning of your comments. We specifically invite Start Printed Page 54669comments 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 can review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you can visit http://dms.dot.gov.

Examining the Docket

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 (800) 647-5227) 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 Docket Management System (DMS) receives them.

Discussion

On January 29, 2004, we issued AD 2004-03-11, amendment 39-13455 (69 FR 5920, February 9, 2004), for certain Boeing Model 747-200C and -200F series airplanes. That AD requires repetitive inspections to find fatigue cracking in the upper chord of certain upper deck floor beams, and repair if necessary. For certain airplanes, that AD also provides an optional repair/modification, which extends certain repetitive inspection intervals. That AD was prompted by a report of fatigue cracking of the station (STA) 340 upper deck floor beam. We issued that 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.

Actions Since Existing AD Was Issued

Since we issued AD 2004-03-11, we have received new reports of cracks in the upper deck floor beams on several airplanes. The airplanes had accumulated between 19,580 and 23,561 total flight cycles. In one case, the aft reinforcing strap of the upper chord of the floor beam at station 520 was found severed at 19,580 total flight cycles. Another airplane with 19,687 total flight cycles had significant cracks in the same area. The threshold for the initial inspection required by AD 2004-03-11 is 22,000 total flight cycles. Therefore, we have determined that the initial inspections and a certain repetitive inspection required by that AD need to be done earlier to detect cracks in the upper deck floor beams in a timely manner.

Relevant Service Information

We have reviewed Revision 1 of Boeing Alert Service Bulletin 747-53A2439, dated March 10, 2005. The inspections, repair, and optional repair/modification described in Revision 1 are essentially identical to those in the original issue, which is referenced in AD 2004-03-11 as the appropriate source of service information for the required actions. Revision 1 reduces the compliance time for all initial inspections and reduces the repetitive inspection interval for surface high frequency eddy current (HFEC) inspection of the upper deck floor beams (header beams) at STAs 440 and 520. The compliance time for accomplishing the inspection of repaired areas ranges between 5,000 and 15,000 flight cycles depending on the diameter of the fastener hole. Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition.

FAA's Determination and Requirements of the Proposed AD

The unsafe condition described previously is likely to exist or develop on other airplanes of the same type design that may be registered in the U.S. at some time in the future. We are proposing to supersede AD 2004-03-11. This proposed AD would continue to require repetitive inspections to find fatigue cracking in the upper chord of the upper deck floor beams, and repair if necessary. This proposed AD would also continue to provide, for certain airplanes, an optional repair/modification, which extends certain repetitive inspection intervals. This proposed AD would also reduce the compliance time for all initial inspections and reduce the repetitive interval for a certain inspection. The actions would be required to be accomplished in accordance with the service bulletin described previously, except as discussed under “Differences Between the Proposed AD and Service Bulletin.”

Differences Between the Proposed AD and Service Bulletin

The service bulletin provides the following information in Note 9 of the Accomplishment Instructions: “For the purposes of this service bulletin, do not count flight-cycles with a cabin pressure differential of 2.0 psi or less. However, any flight-cycle with momentary spikes in cabin pressure differential above 2.0 psi must be included as a full-pressure flight-cycle.” We have determined that an adjustment of flight cycles due to a lower cabin differential pressure is not substantiated and will not be allowed for use in determining the flight cycle threshold for this proposed AD.

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.

Although the Accomplishment Instructions of the service bulletin describe procedures for submitting inspection results to Boeing, this proposed AD would not require that action. We do not need this information from operators.

Change to Existing AD

This proposed AD would retain certain requirements of AD 2004-03-11. Since AD 2004-03-11 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 2004-03-11Corresponding requirement in this proposed AD
Paragraph (a)Paragraphs (f) and (g).
Paragraph (b)Paragraph (h).

Costs of Compliance

There are about 78 airplanes of the affected design in the worldwide fleet. This proposed AD would affect about 21 airplanes of U.S. registry. Start Printed Page 54670

The inspections that are required by AD 2004-03-11 and retained in this proposed 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 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.

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:

Start Part

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 39-13455 (69 FR 5920, February 9, 2004) and adding the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2005-22423; Directorate Identifier 2005-NM-068-AD.

Comments Due Date

(a) The Federal Aviation Administration must receive comments on this AD action by October 31, 2005.

Affected ADs

(b) This AD supersedes AD 2004-03-11, amendment 39-13455.

Applicability

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

Unsafe Condition

(d) This AD was prompted by 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.

Requirements of AD 2004-03-11

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. As of the effective date of this AD, the actions must be done per the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, Revision 1, dated March 10, 2005.

(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. As of the effective date of this AD, do the applicable inspection of the repaired area per Parts 1 and 6 of the Work Instructions of the service bulletin at the applicable time per Table 1 of Part 3 of the Work Instructions of the service bulletin, and repeat the applicable inspection thereafter at intervals not to exceed 3,000 flight cycles.

(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, 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 open-hole HFEC inspection method was used: Repeat that inspection at intervals not to exceed 3,000 flight cycles.

(ii) If the surface HFEC inspection method was used at stations 340 through 420 inclusive and station 500: Repeat that inspection at intervals not to exceed 750 flight cycles.

(iii) If the surface HFEC inspection method was used at stations 440 and 520: Repeat that inspection 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. Start Printed Page 54671

(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 airplanes 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 airplanes 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. 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 per Figure 1 of the service bulletin. As of the effective date of this AD, the actions must be done per Parts 1, 3, and 6 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, Revision 1, dated March 10, 2005, as applicable, and repeat the applicable inspection thereafter at intervals not to exceed 3,000 flight cycles.

(2) Do the modification of the attachment hole of the floor panel per Figure 5 of the service bulletin. 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 per Figure 1 of the service bulletin. As of the effective date of this AD, the actions must be done per Figure 5 and Part 1 of the Work Instructions of Boeing Alert Service Bulletin 747-53A2439, Revision 1, dated March 10, 2005, and repeat the inspection thereafter at intervals not to exceed 3,000 flight cycles.

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.

No Reporting Requirement

(j) 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)

(k)(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) and (g) of this AD.

Start Signature

Issued in Renton, Washington, on September 7, 2005.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

End Signature End Part End Supplemental Information

[FR Doc. 05-18403 Filed 9-15-05; 8:45 am]

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