[Federal Register Volume 64, Number 90 (Tuesday, May 11, 1999)]
[Rules and Regulations]
[Pages 25197-25198]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-11616]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-286-AD; Amendment 39-11163; AD 99-10-10]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-200, -300, and -400 
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 747-200, -300, and -400 series 
airplanes, that requires replacement of fuse pins in the upper link, 
midspar fittings, and diagonal brace of the nacelle strut with new 
corrosion-resistant pins. This amendment is prompted by reports of 
cracked fuse pins in the upper link, midspar fittings, and diagonal 
brace of the nacelle strut due to fatigue and corrosion. The actions 
specified by this AD are intended to prevent cracking or corrosion of 
the fuse pins of the nacelle strut, which could result in failure of 
the fuse pin and strut-to-wing attachment, and consequent loss of the 
strut and separation of the engine from the airplane.

DATES: Effective June 15, 1999.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of June 15, 1999.

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), 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: 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) to include an airworthiness 
directive (AD) that is applicable to certain Boeing Model 747-200, -
300, and -400 series airplanes was published in the Federal Register on 
February 18, 1999 (64 FR 8024). That action proposed to require 
replacement of fuse pins in the upper link, midspar fittings, and 
diagonal brace of the nacelle strut with new corrosion-resistant pins.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the two comments received.
    One commenter supports the proposed rule. The second commenter 
states that the proposed rule will have no impact on it; therefore, the 
commenter supports the proposed 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 as proposed.

Cost Impact

    There are approximately 282 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 43 airplanes of U.S. registry 
will be affected by this AD, that it will take approximately 105 work 
hours per airplane to accomplish the required replacement, and that the 
average labor rate is $60 per work hour. Required parts will be 
provided by the manufacturer at no cost to the operators. Based on 
these figures, the cost impact of the AD on U.S. operators is estimated 
to be $270,900, or $6,300 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.

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 
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 adding the following new 
airworthiness directive:

99-10-10 Boeing: Amendment 39-11163. Docket 98-NM-286-AD.

    Applicability: Model 747-200 and -300 series airplanes equipped 
with General Electric Model CF6-80C2 series engines, and Model 747-
400 series airplanes; as listed in Boeing Service Bulletin 747-54-
2155, Revision 2, dated June 6, 1996, certificated in any category; 
except those airplanes on which modifications of the strut/wing

[[Page 25198]]

structure have been accomplished in accordance either of the 
following AD's:
     AD 95-13-05, amendment 39-9285 (60 FR 33333, June 28, 
1995), or
     AD 95-13-06, amendment 39-9286 (60 FR 33338, 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) 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 prevent cracking or corrosion of the fuse pins of the nacelle 
strut, which could result in failure of the fuse pin and strut-to-
wing attachment, and consequent loss of the strut and separation of 
the engine from the airplane, accomplish the following:
    (a) Within 10 months after the effective date of this AD, 
replace the fuse pins in the upper link, midspar fittings, and 
diagonal brace of the nacelle strut with new corrosion-resistant 
pins, in accordance with the Accomplishment Instructions of Boeing 
Service Bulletin 747-54-2155, Revision 2, dated June 6, 1996.

    Note 2: Replacement of the fuse pins accomplished prior to the 
effective date of this AD in accordance with the Accomplishment 
Instructions of Boeing Service Bulletin 747-54-2155, dated September 
23, 1993, or Revision 1, dated December 8, 1994, is considered 
acceptable for compliance with the applicable action specified in 
this amendment.
    Note 3: All fuse pins in the strut do not have to be replaced at 
the same time; however, the fuse pins do have to be replaced in 
sets, as specified in Boeing Service Bulletin 747-54-2155, Revision 
2, dated June 6, 1996.

    (b) Accomplishment of the replacement of the fuse pins specified 
in paragraph (a) of this AD constitutes terminating action for the 
repetitive inspections of the fuse pins of the upper link, required 
by AD 97-14-06, amendment 39-10064; of the fuse pins of the midspar 
fitting, required by AD 92-24-51, amendment 39-8439; and of the fuse 
pins of the diagonal brace, required by AD 93-03-14, amendment 39-
8518.

Alternative Methods of Compliance

    (c) 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.
    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

    (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.

Incorporation by Reference

    (e) The replacement shall be done in accordance with Boeing 
Service Bulletin 747-54-2155, Revision 2, dated June 6, 1996. 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.
    (f) This amendment becomes effective on June 15, 1999.

    Issued in Renton, Washington, on May 3, 1999.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-11616 Filed 5-10-99; 8:45 am]
BILLING CODE 4910-13-P