Airworthiness Directives; Boeing Model 747-100, 747-200, 747-300, 747SP, and 747SR Series Airplanes Powered by Pratt & Whitney JT9D-3 and JT9D-7 Series Engines

[Federal Register Volume 66, Number 121 (Friday, June 22, 2001)]
[Rules and Regulations]
[Pages 33459-33460]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-15572]



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Federal Register / Vol. 66, No. 121 / Friday, June 22, 2001 / Rules 
and Regulations

[[Page 33459]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-354-AD; Amendment 39-12279; AD 2001-12-23]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-100, 747-200, 747-300, 
747SP, and 747SR Series Airplanes Powered by Pratt & Whitney JT9D-3 and 
JT9D-7 Series Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to certain Boeing Model 747-100, 747-200, 747-300, 
747SP, and 747SR series airplanes powered by Pratt & Whitney JT9D-3 or 
JT9D-7 series engines, that currently requires inspections of the 
vertical chords of the aft torque bulkhead of the outboard nacelle 
struts, and corrective action, if necessary. That AD also gives an 
optional modification of the vertical chords, which ends the 
inspections. This amendment requires the previously optional 
modification. The actions specified by this AD are intended to prevent 
cracking of the vertical chords adjacent to the lower spar fitting, 
which could result in separation of the diagonal brace load path. 
Continued operation with a separated diagonal brace load path increases 
loads on the upper link, midspar fitting, and dual side links, which 
could result in separation of the strut and engine from the airplane.

DATES: Effective July 27, 2001.
    The incorporation by reference of Boeing Alert Service Bulletin 
747-54A2201, dated September 28, 2000, as listed in the regulations, 
was approved previously by the Director of the Federal Register as of 
December 13, 2000 (65 FR 70781, November 28, 2000).

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 Anderson, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, 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 superseding AD 2000-23-25, 
amendment 39-11998 (65 FR 70781, November 28, 2000), which is 
applicable to certain Boeing Model 747-100, 747-200, 747-300, 747SP, 
and 747SR series airplanes powered by Pratt & Whitney JT9D-3 and JT9D-7 
series engines, was published in the Federal Register on December 21, 
2000 (65 FR 80388). The action proposed to continue to require 
inspections of the vertical chords of the aft torque bulkhead of the 
outboard nacelle struts, and corrective action, if necessary. The 
action also proposed to require a previously optional modification of 
the vertical chords, which would end the inspections.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were submitted in response 
to the proposal or the FAA's determination of the cost to the public.

Conclusion

    The FAA has determined that air safety and the public interest 
require the adoption of the rule as proposed.

Cost Impact

    There are approximately 366 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 115 airplanes of U.S. registry 
will be affected by this AD.
    The detailed visual inspections that are currently required by AD 
2000-23-25 take approximately 18 work hours per airplane, at an average 
labor rate of $60 per work hour. Based on these figures, the FAA 
estimates that the cost impact of these inspections on U.S. operators 
is $124,200, or $1,080 per airplane, per inspection cycle.
    The ultrasonic and eddy current inspections that are currently 
required by AD 2000-23-25 take approximately 18 work hours per 
airplane, at an average labor rate of $60 per work hour. Based on these 
figures, the FAA estimates that the cost impact of these inspections on 
U.S. operators is $124,200, or $1,080 per airplane, per inspection 
cycle.
    The new modification that is required by this AD will take 
approximately 48 work hours per airplane, at an average labor rate of 
$60 per work hour. Required parts will cost approximately $10,000 per 
airplane. Based on these figures, the FAA estimates that the cost 
impact of the new modification on U.S. operators is $1,481,200, or 
$12,880 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the current or new 
requirements of this AD, 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 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 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. A final evaluation has been prepared 
for this action and it is

[[Page 33460]]

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 39-11998 (65 FR 
70781, November 28, 2000), and by adding a new airworthiness directive 
(AD), amendment 39-12279, to read as follows:

2001-12-23  Boeing: Amendment 39-12279. Docket 2000-NM-354-AD. 
Supersedes AD 2000-23-25, Amendment 39-11998.

    Applicability: Model 747-100, 747-200, 747-300, 747SP, and 747SR 
series airplanes powered by Pratt & Whitney JT9D-3 or JT9D-7 series 
engines; as listed in Boeing Alert Service Bulletin 747-54A2201, 
dated September 28, 2000; 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 prevent cracking of the vertical chords adjacent to the lower 
spar fitting, which could result in separation of the diagonal brace 
load path and lead to separation of the strut and engine from the 
airplane, accomplish the following:

Restatement of Requirements of AD 2000-23-25: Inspections

    (a) Except as provided by paragraph (b) of this AD, prior to the 
accumulation of 14,000 total flight cycles, or within 90 days after 
December 13, 2000 (the effective date of AD 2000-23-25), whichever 
occurs later: Accomplish paragraphs (a)(1) and (a)(2) of this AD.
    (1) Perform a detailed visual inspection to detect cracking of 
the vertical chords of the aft torque bulkhead of the outboard 
nacelle struts, in accordance with Part 2 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-54A2201, dated 
September 28, 2000. Thereafter, repeat this inspection at intervals 
not to exceed 600 flight cycles until paragraph (d) of this AD is 
accomplished.
    (2) Perform surface eddy current and ultrasonic inspections to 
detect cracking of the vertical chords of the aft torque bulkhead of 
the outboard nacelle struts, in accordance with Part 3 of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
54A2201, dated September 28, 2000. Thereafter, repeat these 
inspections at intervals not to exceed 1,200 flight cycles until 
paragraph (d) of this AD is accomplished.

    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.''

Optional Compliance Time

    (b) If Boeing Service Letter 747-54-055, dated April 24, 1998, 
was accomplished on the airplane during the modification of the 
nacelle strut in accordance with AD 95-10-16, amendment 39-9233: 
Accomplishment of the initial inspection in paragraph (a) of this AD 
may be deferred until 3,000 flight cycles after accomplishment of 
the service letter.

Repair

    (c) If any cracking is detected during any inspection or 
modification required by this AD: Prior to further flight, 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 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.

New Requirements of this AD: Modification (Terminating Action)

    (d) Within 4 years after the effective date of this AD, do the 
modification of the vertical chords of the aft torque bulkhead of 
the outboard nacelle struts according to Part 4 of Boeing Alert 
Service Bulletin 747-54A2201, dated September 28, 2000. After this 
modification, stop the repetitive inspections required by paragraph 
(a) of 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 3: 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) Except as provided by paragraph (c) of this AD, the actions 
shall be done in accordance with Boeing Alert Service Bulletin 747-
54A2201, dated September 28, 2000. The incorporation by reference of 
that document was approved previously by the Director of the Federal 
Register as of December 13, 2000 (65 FR 70781, November 28, 2000). 
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 July 27, 2001.

    Issued in Renton, Washington, on June 14, 2001.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-15572 Filed 6-21-01; 8:45 am]
BILLING CODE 4910-13-U

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