[Federal Register Volume 66, Number 108 (Tuesday, June 5, 2001)]
[Proposed Rules]
[Pages 30109-30112]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-14043]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-220-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD), applicable to all Boeing Model 747 series 
airplanes, that currently requires a one-time inspection of the 
fuselage skin adjacent to the drag splice fitting to detect cracking, 
and follow-on actions, if necessary. This action would mandate new 
repetitive inspections for cracking of the fuselage skin adjacent to 
the drag splice fitting. This proposal is prompted by reports of 
fatigue cracking in the fuselage skin and adjacent structure. The 
actions specified by the proposed AD are intended to detect and correct 
such cracking, which could result in reduced structural integrity of 
the fuselage, and consequent rapid depressurization of the airplane.

DATES: Comments must be received by July 20, 2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2000-NM-220-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9:00 a.m. and 3 p.m., Monday through Friday, except 
Federal holidays. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2000-NM-220-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.
    The service information referenced in the proposed rule may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: Rick Kawaguchi, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-1153; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications shall identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this action may be changed in 
light of the comments received.
     Submit comments using the following format:
     Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
     For each issue, state what specific change to the proposed 
AD is being requested.
     Include justification (e.g., reasons or data) for each 
request.

[[Page 30110]]

    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2000-NM-220-AD.'' The postcard will be date stamped 
and returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules 
Docket No. 2000-NM-220-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On July 3, 2000, the FAA issued AD 2000-14-04, amendment 39-11813 
(65 FR 43219, July 13, 2000), applicable to all Boeing Model 747 series 
airplanes, to require a one-time inspection of the fuselage skin 
adjacent to the drag splice fitting to detect cracking, and follow-on 
actions, if necessary. The requirements of that AD are intended to 
detect and correct fatigue cracking of the fuselage skin, which could 
result in reduced structural integrity of the fuselage, and consequent 
rapid depressurization of the airplane.

Actions Since Issuance of Previous Rule

    In the preamble to AD 2000-14-04, the FAA specified that the 
actions required by that AD were considered ``interim action'' and that 
the FAA was considering a separate rulemaking action to address the 
procedures for repetitive ultrasonic, high frequency eddy current, and 
detailed visual inspections of the fuselage skin adjacent to the drag 
splice fitting to detect additional cracking, and repair of any 
cracking detected, as described in Boeing Service Bulletin 747-53A2444, 
Revision 1, dated June 15, 2000 (which was referenced as the 
appropriate source of service information in that AD). The FAA now has 
determined that further rulemaking action is indeed necessary, and this 
proposed AD follows from that determination.

New Service Information

    Since the issuance of AD 2000-14-04, the FAA has received a report 
of severe cracking on a Model 747 series airplane at approximately 
14,540 flight cycles. In light of this report, the FAA has reviewed and 
approved Boeing Alert Service Bulletin 747-53A2444, Revision 2, dated 
May 24, 2001. Revision 2 is essentially the same as Revision 1 of the 
service bulletin, but Revision 2 specifies more comprehensive 
repetitive inspection procedures and reduces the compliance times 
specified in Revision 1. Revision 2 also references a procedure in the 
747 Structural Repair Manual for the repair of certain cracking without 
further FAA approval.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would supersede AD 2000-14-04 to continue to require a one-
time inspection of the fuselage skin adjacent to the drag splice 
fitting to detect cracking, and follow-on actions, if necessary. This 
proposed AD also mandates new repetitive inspections for cracking of 
the fuselage skin adjacent to the drag splice fitting.

Differences Between Alert Service Bulletin and This Proposed AD

    The service bulletin references the 747 Structural Repair Manual 
(SRM) Subject 53-30-03, Figure 60, as an appropriate source of service 
information for accomplishment of the repair of the fuselage skin. 
Certain revisions to this chapter of the 747 SRM allow the use of 7075-
T6 aluminum as an option for skin replacement when accomplishing the 
repair on the fuselage skin. Because 7075-T6 aluminum is significantly 
less durable than 2024-T3 aluminum, the FAA has determined that use of 
7075-T6 as a repair material cannot be allowed. Future repairs of the 
subject area that require skin replacement may only use the 2024-T3 
material. Existing repairs of the subject area already made from 7075-
T6 aluminum will require follow-on inspections accomplished in a manner 
approved by the FAA.
    Although the service bulletin specifies that the manufacturer may 
be contacted for disposition of certain repair conditions, this 
proposal would require the repair of those conditions to be 
accomplished per a method approved by the FAA, or 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 Aircraft Certification Office, to make such findings.

Interim Action

    This is interim action. The manufacturer has advised that it is 
developing a modification that will positively address the unsafe 
condition addressed by this AD. Once this modification is developed, 
approved, and available, the FAA may consider additional rulemaking.

Cost Impact

    There are approximately 1,301 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 260 airplanes of U.S. 
registry would be affected by this proposed AD.
    The actions that are currently required by AD 2000-14-04 take 
approximately 2 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Based on these figures, the cost 
impact of the currently required actions on U.S. operators is estimated 
to be $31,200, or $120 per airplane.
    The new inspections that are proposed in this AD action would take 
approximately 7 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Based on these figures, the cost 
impact of the new proposed requirements of this AD on U.S. operators is 
estimated to be $109,200, or $420 per airplane, per inspection cycle.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the current or proposed 
requirements of this AD action, and that no operator would accomplish 
those actions in the future if this AD were not adopted. The cost 
impact figures discussed in AD rulemaking actions represent only the 
time necessary to perform the specific actions actually required by the 
AD. These figures typically do not include incidental costs, such as 
the time required to gain access and close up, planning time, or time 
necessitated by other administrative actions.

Regulatory Impact

    The regulations proposed herein 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. Therefore, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    For the reasons discussed above, I certify that this proposed 
regulation (1)

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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) if promulgated, 
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. A copy of the draft regulatory evaluation 
prepared for this action is contained in the Rules Docket. A copy of it 
may be obtained by contacting the Rules Docket at the location provided 
under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
part 39 of the Federal Aviation Regulations (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.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing amendment 39-11813 (65 FR 
43219, July 13, 2000), and by adding a new airworthiness directive 
(AD), to read as follows:

Boeing: Docket 2000-NM-220-AD. Supersedes AD 2000-14-04, Amendment 
39-11813.

    Applicability: All Model 747 series airplanes, certificated in 
any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (e)(1) 
of this AD. The request should include an assessment of the effect 
of the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To detect and correct fatigue cracking of certain areas of the 
fuselage skin, which could result in reduced structural integrity of 
the fuselage, and consequent rapid depressurization of the airplane; 
accomplish the following:

Restatement of Requirements of AD 2000-14-04

One-Time Detailed Visual Inspection

    (a) Prior to the accumulation of 13,000 total flight cycles or 
within 60 days after July 28, 2000 (the effective date of AD 2000-
14-04, amendment 39-11813), whichever occurs later: Perform a one-
time external detailed visual inspection of the fuselage skin 
adjacent to the drag splice fitting as illustrated in Figure 2 of 
Boeing Service Bulletin 747-53A2444, Revision 1, dated June 15, 
2000. If no cracking is detected, no further action is required by 
this paragraph.

    Note 2: For the purposes of this AD, a detailed visual 
inspection is defined as: ``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.''

Corrective Action

    (b) If any cracking is detected during any inspection required 
by this AD, prior to further flight, repair in accordance with 
Boeing Alert Service Bulletin 747-53A2444, Revision 2, dated May 24, 
2001. Where the service bulletin specifies to contact Boeing for 
repair instructions, 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) 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 
approval letter must specifically reference this AD.

    Note 3: Repairs accomplished prior to the effective date of this 
AD in accordance with a method approved by the Manager, Seattle ACO, 
FAA, or in accordance with data meeting the type certification basis 
of the airplane approved by a Boeing Company DER, are considered 
acceptable for compliance with the repair specified in paragraph (b) 
of this AD.


    Note 4: Boeing Alert Service Bulletin 747-53A2444, Revision 2, 
dated May 24, 2001, references the 747 Structural Repair Manual 
(SRM) as an appropriate source of service information for 
accomplishment of the repair of the fuselage skin. However, the use 
of 7075-T6 aluminum as specified in certain revisions of the SRM is 
not an option for skin replacement when accomplishing the subject 
repair.

Secondary Inspection

    (c) For airplanes on which cracking is detected during any 
inspection required by paragraph (a) or (d) of this AD, prior to 
further flight after accomplishment of paragraph (b) of this AD: 
Determine if a secondary inspection of adjacent structure is 
required, using the Logic Diagram illustrated in Figure 1 of Boeing 
Service Bulletin 747-53A2444, Revision 1, dated June 15, 2000, or 
Boeing Alert Service Bulletin 747-53A2444, Revision 2, dated May 24, 
2001. If required, before further flight, accomplish the inspection 
in accordance with the service bulletin.

    Note 5: Inspections and repairs accomplished prior to July 28, 
2000, in accordance with Boeing Alert Service Bulletin 747-53A2444, 
dated May 25, 2000, are considered acceptable for compliance with 
the applicable actions specified in this amendment.

New Requirements of This AD

Repetitive Inspections

    (d) Perform ultrasonic, high frequency eddy current, and 
detailed visual inspections in accordance with the Work Instructions 
of Boeing Alert Service Bulletin 747-53A2444, Revision 2, dated May 
24, 2001, at the applicable times specified in Figure 1 of the Logic 
Diagram of the service bulletin; except where the compliance time in 
the logic diagram specifies an interval of ``after the release date 
of the service bulletin,'' this AD requires compliance within the 
interval specified in the service bulletin ``after the effective 
date of this AD.'' Repeat the applicable inspections at the 
intervals shown in Figure 1 of the Logic Diagram of the service 
bulletin. Accomplishment of the inspections required by this 
paragraph ends the inspections required by paragraph (a) of this AD.

    Note 6: Where there are differences between the AD and the 
service bulletin, the AD prevails.

Alternative Methods of Compliance

    (e)(1) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Seattle ACO. Operators shall submit 
their requests through an appropriate FAA Principal Maintenance 
Inspector, who may add comments and then send it to the Manager, 
Seattle ACO.
    (2) Alternative methods of compliance, approved previously in 
accordance with AD 2000-14-04, amendment 39-11813, are approved as 
alternative methods of compliance with this AD.

    Note 7: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Special Flight Permits

    (f) Special flight permits may be issued in accordance with 
Secs. 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 
21.197 and 21.199) to operate the airplane to a location where the 
requirements of this AD can be accomplished.


[[Page 30112]]


    Issued in Renton, Washington, on May 30, 2001.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-14043 Filed 6-4-01; 8:45 am]
BILLING CODE 4910-13-U