AD 2001-16-02

[Federal Register Volume 66, Number 153 (Wednesday, August 8, 2001)]
[Rules and Regulations]
[Pages 41440-41443]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 01-19245]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-314-AD; Amendment 39-12370; AD 2001-16-02]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Boeing Model 747 series airplanes, that requires 
repetitive inspections to find cracking of the frame web, strap, inner 
chords, and inner chord angle of the forward edge frame of the number 5 
main entry door cutout, and repair, if necessary. These actions are 
necessary to find and fix such cracking, which could result in severing 
of the frame, inability of the edge frame to react door stop loads, and 
consequent rapid depressurization of the airplane. This action is 
intended to address the identified unsafe condition.

DATES: Effective September 12, 2001.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of September 12, 2001.

ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the Federal 
Aviation Administration (FAA),

[[Page 41441]]

Transport Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., 
Renton, Washington; or at the Office of the Federal Register, 800 North 
Capitol Street, NW., suite 700, Washington, DC.

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: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain Boeing Model 747 series 
airplanes was published in the Federal Register on March 20, 2001 (66 
FR 15662). That action proposed to require repetitive inspections to 
find cracking of the frame web, strap, inner chords, and inner chord 
angle of the forward edge frame of the number 5 main entry door cutout; 
and repair, if necessary.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    Two commenters have no objection to the proposed rule.

Limit Applicability

    One commenter, the manufacturer, states that, subsequent to 
issuance of Revision 2 of the referenced service bulletin, it committed 
to a production revision at line number 1305, Production Revision 
Request 85415, which eliminates the need for the inspections in the 
proposed rule for airplanes with and after that line number. The 
commenter recommends that the applicability in the proposed rule be 
limited to Model 747 series airplanes, line numbers 1 through 1304, 
except Model 747SP.
    The FAA partially agrees. We will change the applicability section 
in the final rule to specify all affected models in the subject line of 
the final rule; it will not include the 747SP series airplane. However, 
because the Production Revision Request has not yet been incorporated, 
we cannot limit the line number applicability.

Clarification of Compliance Time--Paragraph (a)

    One commenter asks that paragraph (a) of the proposed rule be 
changed. The commenter states that paragraph (a)(1) of the proposed 
rule does not actually state a compliance time or refer to the 
referenced service bulletin as a means of compliance. The commenter 
adds that paragraph (a)(2) of the proposed rule calls for the 
inspection to be done within 3,000 flight cycles after the first 
inspection in the bulletin. Therefore, the inspection may never be done 
if operators decide not to do the bulletin, but the commenter presumes 
this statement has been added for those operators that did the 
inspection before the release of the AD, per the bulletin. The 
commenter notes paragraph (a)(2) is redundant because repeat 
inspections will already have been carried out per the bulletin. The 
commenter states that the specified compliance times are very difficult 
to understand and suggests the following wording for the compliance 
times be used in the proposed rule:
    <bullet> At the times specified in the logic diagram of the 
referenced service bulletin, except substituting ``receipt of service 
bulletin'' for ``effective date of this AD.'' Or
    <bullet> Within 3,000 flight cycles from the effective date of the 
AD, whichever is later. The commenter's interpretation of paragraph 
(a)(2) of the proposed rule is that the commenter would have until 
3,000 flight cycles after the inspection at 16,000 flight cycles to 
inspect its oldest airplane.
    The FAA partially concurs. (The paragraph numbering in the final 
rule has been revised.) Paragraph (b) of the final rule has been 
changed for clarification, to specifically cite accomplishment of the 
inspection at the applicable time specified in the logic diagram in 
Figure 1 of the service bulletin. However, we do not concur that 
paragraph (c) of the final rule should be revised to within 3,000 
flight cycles from the effective date of the AD. Paragraph (c) 
addresses those operators who have already accomplished the inspections 
per previous revisions of the service bulletin. The 3,000-flight-cycle 
threshold allows operators to transition from the old revisions to the 
revision of the service bulletin specified in this final rule.
    Additionally, we do not concur that the commenter would have until 
3,000 flight cycles after the inspection at 16,000 flight cycles to 
accomplish the initial inspection on its airplanes. The commenter has 
not accomplished the inspections on its airplanes per the old revisions 
to the service bulletin, so paragraph (c) does not apply, and the 
commenter must accomplish the initial inspection at the 16,000-flight-
cycle threshold as mandated by paragraph (b) of the final rule.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Interim Action

    This is considered to be interim action. The manufacturer has 
advised that it currently 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 1,314 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 258 airplanes of U.S. 
registry will be affected by this AD, that it will take approximately 
16 work hours per airplane to accomplish the required inspections, and 
that the average labor rate is $60 per work hour. Based on these 
figures, the cost impact of the inspections required by this AD on U.S. 
operators is estimated to be $247,680, or $960 per airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the 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 adopted herein 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. Therefore, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.
    For the reasons discussed above, I certify that this action (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)

[[Page 41442]]

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 final evaluation has been prepared for 
this action and it is contained in the Rules Docket. A copy of it may 
be obtained from the Rules Docket at the location provided under the 
caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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 adding the following new 
airworthiness directive:

2001-16-02  Boeing: Amendment 39-12370. Docket 2000-NM-314-AD.

    Applicability: All Model 747-100, -200B, -200F, -200C, -100B, -
300, -100B SUD, -400, -400D, -400F, and 747SR 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) 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 find and fix cracking of the frame web, strap, inner chords, 
and inner chord angle of the forward edge frame of the number 5 main 
entry door cutout, which could result in severing of the frame, 
inability of the edge frame to react door stop loads, and consequent 
rapid depressurization of the airplane, accomplish the following:

Repetitive Inspections (No Terminating Action)

    (a) Inspect the airplane for cracks per Boeing Alert Service 
Bulletin 747-53A2450, Revision 2, including Appendix A, dated 
January 4, 2001; at the later of the times specified in either 
paragraph (b) or (c) of this AD, per Table 1 as follows:

                    Table 1.--Inspection Requirements
------------------------------------------------------------------------
                Type of inspection                     Area to inspect
------------------------------------------------------------------------
(1) Detailed Visual...............................  Strap 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 HFEC................................  Station 2231 frame
                                                     fastener locations
                                                     per Figures 4 and
                                                     7, and either
                                                     Figure 5 or 6 of
                                                     the service
                                                     bulletin, as
                                                     applicable.
(4) Surface HFEC..................................  Around 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 Current....................  Station 2231 frame
                                                     strap in areas
                                                     covered by the
                                                     reveal per Figure 5
                                                     or Figure 6 of the
                                                     service bulletin,
                                                     as applicable.
------------------------------------------------------------------------

    (b) Do the inspections per Table 1 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 the effective date of this AD.'' Repeat the inspections 
after that at intervals not to exceed 3,000 flight cycles.
    (c) 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 after that at intervals not to exceed 3,000 
flight cycles.

    Note 2: There is no terminating action currently available for 
the inspections required by paragraph (a) of this AD.


    Note 3: Where there are differences between the AD and the alert 
service bulletin, the AD prevails.

Repair

    (d) If any cracking is found during any inspection required by 
paragraph (a) of this AD, before further flight, repair per a method 
approved by the Manager, Seattle Aircraft Certification Office 
(ACO), 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 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.

Alternative Methods of Compliance

    (e) 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.

    Note 4: 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 
sections 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.

Incorporation by Reference

    (g) The inspections shall be done in accordance with Boeing 
Alert Service Bulletin 747-53A2450, Revision 2, including Appendix 
A, dated January 4, 2001. This incorporation by reference was 
approved by the Director of the Federal Register in accordance with 
5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from 
Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 
98124-2207. Copies may be inspected at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the 
Office of the Federal Register, 800 North Capitol Street, NW., suite 
700, Washington, DC.

Effective Date

    (h) This amendment becomes effective on September 12, 2001.


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    Issued in Renton, Washington, on July 26, 2001.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-19245 Filed 8-7-01; 8:45 am]
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