AD Amdt-39-10982

[Federal Register Volume 64, Number 4 (Thursday, January 7, 1999)]
[Rules and Regulations]
[Pages 985-986]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 99-186]



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Federal Register / Vol. 64, No. 4 / Thursday, January 7, 1999 / Rules 
and Regulations

[[Page 985]]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-308-AD; Amendment 39-10982; AD 97-20-01 R1]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment revises an existing airworthiness directive 
(AD), applicable to certain Boeing Model 747 series airplanes, that 
currently requires repetitive inspections to detect cracks, corrosion, 
or damage of the lower spar fitting body and lug, and corrective 
actions, if necessary. That AD also provides for optional terminating 
action for the repetitive inspection requirements. That AD was prompted 
by reports that fatigue cracking was found in the lower spar fitting 
lug on the number 3 pylon and in the lower spar fitting body. The 
actions specified by that AD are intended to detect and correct such 
fatigue cracking, which could result in failure of the strut and 
separation of the engine from the airplane. This amendment references 
additional service bulletins for accomplishment of the optional 
replacement, and clarifies that accomplishment of certain AD's 
terminates the repetitive inspections.

DATES: Effective February 11, 1999.
    The incorporation by reference of certain publications, as listed 
in the regulations, was approved previously by the Director of the 
Federal Register as of October 7, 1997 (62 FR 49431, September 22, 
1997).

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 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.

FOR FURTHER INFORMATION CONTACT: Tamara L. Anderson, Aerospace 
Engineer, Airframe Branch, ANM-120S, FAA, Transport Airplane 
Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue, 
SW., Renton, Washington 98055-4056; telephone (425) 227-2771; fax (425) 
227-1181.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by revising AD 97-20-01, 
amendment 39-10139 (62 FR 49431, September 22, 1997), which is 
applicable to certain Boeing Model 747 series airplanes, was published 
in the Federal Register on April 3, 1998 (63 FR 16449). That action 
proposed to continue to require repetitive inspections to detect 
cracks, corrosion, or damage of the lower spar fitting body and lug, 
and corrective actions, if necessary. The action also proposed to 
provide for optional terminating action for the repetitive inspection 
requirements.

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.

Support for the Proposal

    Two commenters support the proposed rule.

Requests To Withdraw the Proposal

    Two commenters state that the proposed revision of AD 97-20-01 is 
not necessary because the intent of the revision was approved 
previously by the FAA under the ``global'' alternative method of 
compliance (AMOC) 97-120S-743, which was issued to Boeing on November 
12, 1997, and under Boeing letter B-T113-97-5439, dated November 5, 
1997.
    The FAA infers from these remarks that the commenters request that 
the proposed AD be withdrawn. The FAA does not concur. Although the FAA 
agrees that the intent of the proposed revision to AD 97-20-01 is the 
same as the previously referenced AMOC for that AD, the FAA has 
determined that the revision to that AD is necessary. First, the 
revision clarifies the requirements for any future operators who may 
not be aware of an existing AMOC. Second, any non-U.S. registered 
airplanes that are subsequently placed on the U.S. Register will be 
required to comply with the revision to AD 97-20-01. In addition, the 
revision will assist FAA principal maintenance inspectors in 
determining compliance with the final rule. In light of these factors, 
the FAA considers it necessary to issue the final rule. Paragraph 
(c)(2) has been added to the final rule to clarify that AMOC's, 
approved previously in accordance with AD 97-20-01, are approved as 
AMOC's with the requirements of this AD.

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 as proposed. The FAA has 
determined that these changes will neither increase the economic burden 
on any operator nor increase the scope of the AD.

Cost Impact

    There are approximately 367 Model 747 series airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 152 
airplanes of U.S. registry will be affected by this AD, that it will 
take approximately 19 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 $173,280, or 
$1,140 per airplane, per inspection cycle.
    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.

Regulatory Impact

    The regulations adopted herein will not have substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and

[[Page 986]]

responsibilities among the various levels of government. Therefore, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    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) 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 removing amendment 39-10139 (62 FR 
49431, September 22, 1997) and by adding a new airworthiness directive 
(AD), amendment 39-10982, to read as follows:

97-20-01 R1  Boeing: Amendment 39-10982. Docket 97-NM-308-AD. 
Revises AD 97-20-01, Amendment 39-10139.

    Applicability: Model 747 series airplanes, having line numbers 1 
through 500 inclusive, equipped with Pratt & Whitney Model JT9D-3, -
7, or -7Q engines, or having line numbers 202, 204, 232, or 257, 
equipped with General Electric Model CF6 series engines; 
certificated in any category; and on which the strut/wing 
modification has not been accomplished in accordance with either of 
the following AD's:
    <bullet> AD 95-10-16, amendment 39-9233 (60 FR 27008, May 22, 
1995), or
    <bullet> AD 95-13-07, amendment 39-9287 (60 FR 33336, June 28, 
1995).

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
otherwise 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 (c)(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 in the lower spar fitting 
lug or the lower spar fitting body, which could result in failure of 
the strut and separation of the engine from the airplane, accomplish 
the following:
    (a) Within 90 days after October 7, 1997 (the effective date of 
AD 97-20-01, amendment 39-10139) perform a detailed visual 
inspection and an ultrasonic inspection to detect cracks, corrosion, 
or damage of the lower spar fitting body and lug, as applicable, in 
accordance with Figures 9 and 10 of Boeing Service Bulletin 747-54-
2062, Revision 8, dated August 21, 1997.

    Note 2: This AD does not require an inspection of the inboard 
strut-to-diagonal brace attach fitting as described in Figure 1 of 
Boeing Service Bulletin 747-54-2062, Revision 8, dated August 21, 
1997. However, this inspection is required to be accomplished as 
part of AD 95-20-05, amendment 39-9383 (60 FR 51705, October 10, 
1995).

    (1) If no crack, corrosion, or damage is detected, repeat the 
detailed visual and ultrasonic inspections thereafter at intervals 
not to exceed 400 landings.
    (2) If any crack, corrosion, or damage is detected, prior to 
further flight, accomplish either paragraph (a)(2)(i) or (a)(2)(ii) 
of this AD.
    (i) Replace the lower spar fitting with a new steel lower spar 
fitting, in accordance with Part II of the Accomplishment 
Instructions of the service bulletin. Or
    (ii) Modify the nacelle strut and wing structure in accordance 
with AD 95-10-16, amendment 39-9233 (60 FR 27008, May 22, 1995), or 
AD 95-13-07, amendment 39-9287 (60 FR 33336, June 28, 1995).
    (b) Replacement of the lower spar fitting with a new steel lower 
spar fitting, in accordance with Part II of the Accomplishment 
Instructions of any of the following service bulletins listed below, 
or accomplishment of modification of the nacelle strut and wing 
structure required by AD 95-10-16, amendment 39-9233 (60 FR 27008, 
May 22, 1995), or AD 95-13-07, amendment 39-9287 (60 FR 33336, June 
28, 1995); constitutes terminating action for the repetitive 
inspection requirements of this AD.
    <bullet> Boeing Service Bulletin 747-54-2062, Revision 1, dated 
November 13, 1980;
    <bullet> Boeing Service Bulletin 747-54-2062, Revision 2, dated 
March 19, 1981;
    <bullet> Boeing Service Bulletin 747-54-2062, Revision 3, dated 
August 28, 1981;
    <bullet> Boeing Service Bulletin 747-54-2062, Revision 4, dated 
June 30, 1982;
    <bullet> Boeing Service Bulletin 747-54-2062, Revision 5, dated 
June 1, 1984;
    <bullet> Boeing Service Bulletin 747-54-2062, Revision 6, dated 
October 2, 1986;
    <bullet> Boeing Service Bulletin 747-54-2062, Revision 7, dated 
December 21, 1994;
    <bullet> Boeing Service Bulletin 747-54-2062, Revision 8, dated 
August 21, 1997.
    (c)(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 Aircraft Certification 
Office (ACO), FAA, Transport Airplane Directorate. 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 97-20-01, are approved as alternative methods of 
compliance with the requirements of this AD.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

    (d) 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.
    (e) Certain actions shall be done in accordance with Boeing 
Service Bulletin 747-54-2062, Revision 8, dated August 21, 1997. The 
incorporation by reference of this document was approved previously 
by the Director of the Federal Register, in accordance with 5 U.S.C. 
552(a) and 1 CFR part 51, as of October 7, 1997 (62 FR 49431, 
September 22, 1997). 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, 
Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., 
Renton, Washington; or at the Office of the Federal Register, 800 
North Capitol Street, NW., suite 700, Washington, DC.
    (f) This amendment becomes effective on February 11, 1999.

    Issued in Renton, Washington, on December 30, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-186 Filed 1-6-99; 8:45 am]
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