AD 2001-17-25

[Federal Register Volume 66, Number 168 (Wednesday, August 29, 2001)]
[Rules and Regulations]
[Pages 45573-45575]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 01-21492]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-294-AD; Amendment 39-12416; AD 2001-17-25]
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 supersedes an existing airworthiness directive 
(AD), applicable to certain Boeing Model 747 series airplanes, that 
currently requires inspection of the aft trunnion of the wing landing 
gear for cracks and corrosion, and corrective action, if necessary. 
This amendment requires new repetitive inspections for cracks or 
corrosion of the aft trunnion outer cylinders of the wing landing gear, 
follow-on actions, and repetitive overhaul of the wing landing gear. 
The new actions also apply to airplanes not included in the 
applicability of the existing AD. The actions specified by this AD are 
intended to find and fix cracking or corrosion of the aft trunnion of 
the wing landing gear, which could result in collapse of the wing 
landing gear and consequent reduced controllability of the airplane.

DATES: Effective October 3, 2001.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of October 3, 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), 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 90-06-18 R1, 
amendment 39-6706 (55 FR 33650, August 17, 1990), which is applicable 
to certain Boeing Model 747 series airplanes, was published in the 
Federal Register on April 25, 2001 (66 FR 20763). The action proposed 
to continue to require inspection of the aft trunnion of the wing 
landing gear for cracks and corrosion, and corrective action, if 
necessary. The action also proposed to require new repetitive 
inspections for cracks or corrosion of the aft trunnion outer cylinders 
of the wing landing gear, follow-on actions, and repetitive overhaul of 
the wing landing gear. The new proposed actions would also apply to 
airplanes not included in the applicability of the existing AD.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the single comment received.

Clarify Requirements of Paragraph (c) for New Production Airplanes

    One commenter states that paragraph (c) of the proposed rule does 
not give credit for new-production airplanes and asks that the FAA 
clarify requirements for such new airplanes.
    We infer that the commenter is concerned about the compliance time 
for the actions required by paragraph (c) of this AD, and we concur 
that we need to revise the compliance time to accommodate new 
airplanes. As

[[Page 45574]]

paragraph (c) is written in the proposed rule, new airplanes delivered 
after 180 days after the effective date of this AD may be grounded 
until the actions required by paragraph (c) of this AD are done. 
Therefore, we have revised the compliance time of paragraph (c) of this 
AD to 180 days since the airplane's date of manufacture, or 180 days 
after the effective date of this AD, whichever occurs later. We find 
that this compliance time will allow adequate time for new airplanes to 
continue to operate before complying with paragraph (c) of this AD 
without compromising safety.

Conclusion

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

Cost Impact

    There are approximately 1,132 Model 747 series airplanes of the 
affected design in the worldwide fleet.
    In AD 90-06-18 R1, the FAA estimated that the actions in that AD 
would affect 163 airplanes of U.S. registry. The actions that are 
currently required by AD 90-06-18 R1 take approximately 45 work hours 
per airplane to accomplish, at an average labor rate of $60 per work 
hour. Based on these figures, the FAA estimates the cost impact of the 
currently required actions on U.S. operators to be $440,100, or $2,700 
per airplane, per inspection cycle.
    The FAA estimates that this new AD will affect 233 airplanes of 
U.S. registry. The new inspections required by this AD will take 
approximately 8 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Based on these figures, the FAA 
estimates the cost impact of these required inspections on U.S. 
operators to be $111,840, or $480 per airplane, per inspection cycle.
    The new overhaul required by this AD action will take approximately 
320 work hours per airplane to accomplish, at an average labor rate of 
$60 per work hour. Based on these figures, the FAA estimates the cost 
impact of the required overhaul on U.S. operators to be $4,473,600, or 
$19,200 per airplane, per overhaul.
    The cost impact figures discussed above are 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) 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 39-6706 (55 FR 
33650, August 17, 1990), and by adding a new airworthiness directive 
(AD), amendment 39-12416, to read as follows:

2001-17-25 Boeing: Amendment 39-12416. Docket 2000-NM-294-AD. 
Supersedes AD 90-06-18 R1, Amendment 39-6706.

    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 find and fix cracking or corrosion of the aft trunnion of the 
wing landing gear, which could result in collapse of the wing 
landing gear and consequent reduced controllability of the airplane, 
accomplish the following:

Restatement of Requirements of AD 90-06-18 R1

Repetitive Inspections and Corrective Actions (Certain Airplanes)

    (a) For airplanes listed in Groups 1, 2, and 3 in Boeing Service 
Bulletin 747-32-2190, Revision 4, dated October 26, 1989, inspect as 
follows:
    (1) Within the next 120 days after August 17, 1990 (the 
effective date of AD 90-06-18 R1, amendment 39-6706), perform a 
visual inspection, or a visual-plus-eddy-current inspection, of the 
wing landing gear at the trunnion, for cracks and corrosion, in 
accordance with Boeing Service Bulletin 747-32-2190, Revision 4, 
dated October 26, 1989.
    (2) If no cracks or corrosion are found, repeat the inspection 
described in paragraph (a)(1) of this AD at intervals not to exceed 
6 months if the visual inspection option was selected for the 
previous inspection, or at intervals not to exceed 18 months if the 
visual-plus-eddy-current inspection option was selected for the 
previous inspection. Doing paragraph (b), (c), or (d) of this AD 
ends the repetitive inspections required by this paragraph.
    (3) Except as provided by paragraph (a)(4) of this AD, if cracks 
or corrosion are found, prior to further flight, remove and rework 
or replace cracked/corroded parts in accordance with Boeing Service 
Bulletin 747-32-2190, Revision 4, dated October 26, 1989.
    (4) If only corrosion is found, as an alternative to paragraph 
(a)(3) of this AD, accomplish the terminating action described in 
Boeing Service Bulletin 747-32-2190, Revision 4, dated October 26, 
1989, within 12 months after detection of corrosion, but no later 
than 36 months after August 17, 1990; and high frequency eddy 
current inspect the

[[Page 45575]]

wing landing gear trunnion at intervals not to exceed 6 months, 
until the terminating action is accomplished. Doing paragraph (b), 
(c), or (d) of this AD ends the repetitive inspections required by 
this paragraph.

Optional Terminating Action for Requirements of Paragraph (a)

    (b) For airplanes listed in Groups 1, 2, and 3 in Boeing Service 
Bulletin 747-32-2190, Revision 4, dated October 26, 1989: 
Modification in accordance with Boeing Service Bulletin 747-32-2190, 
Revision 4, dated October 26, 1989, constitutes terminating action 
for the reinspection requirements of paragraph (a) of this AD.

New Requirements of This AD

Repetitive Detailed Visual Inspections and Follow-On Actions (All 
Airplanes)

    (c) Within 180 days since the airplane's date of delivery or 180 
days after the effective date of this AD, whichever occurs later, do 
a detailed visual inspection using a borescope to find cracking and 
corrosion of the aft trunnion outer cylinders of the wing landing 
gear. Do the inspection per Figure 2 of Boeing Alert Service 
Bulletin 747-32A2465, Revision 1, dated July 20, 2000. The detailed 
visual inspection is contained in Part 1 of the service bulletin. 
Thereafter, repeat the inspection at intervals not to exceed 6 
months.
    (1) If no corrosion or cracking is found during any inspection 
per paragraph (c) of this AD, before further flight, apply corrosion 
preventative compound, per the service bulletin. Repeat the 
application of corrosion preventative compound after each inspection 
per paragraph (c) of this AD.
    (2) If any corrosion or cracking is found during any inspection 
per paragraph (c) 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 (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 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.''

Overhaul (All Airplanes)

    (d) At the applicable compliance time stated in paragraph (d)(1) 
or (d)(2) of this AD, and thereafter at intervals not to exceed 10 
years, overhaul the wing landing gear per Flag Note 2 of Figure 1 of 
Boeing Alert Service Bulletin 747-32A2465, Revision 1, dated July 
20, 2000. If any cracking or corrosion outside the overhaul limits 
is found during this overhaul, before further flight, repair per a 
method approved by the Manager, Seattle ACO; or per data meeting the 
type certification basis of the airplane approved by a Boeing 
Company 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. For affected airplanes, 
doing this overhaul ends the repetitive inspections required by 
paragraph (a) of this AD.
    (1) For Group 1 airplanes listed in Boeing Alert Service 
Bulletin 747-32A2465, Revision 1, on which the wing landing gear has 
NOT been modified per Flag Note 1 of Figure 1 of the service 
bulletin: Overhaul the wing landing gear within 48 months after the 
effective date of this AD.
    (2) For Group 1 airplanes listed in Boeing Alert Service 
Bulletin 747-32A2465, Revision 1, on which the wing landing gear HAS 
been modified per Flag Note 1 of Figure 1 of the service bulletin; 
OR for Groups 2 and 3 airplanes listed in Boeing Alert Service 
Bulletin 747-32A2465, Revision 1: Overhaul the wing landing gear 
within 10 years since delivery of the airplane or last overhaul, or 
within 180 days after the effective date of this AD, whichever comes 
later.

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 90-06-18 R1, amendment 39-6706, are approved as 
alternative methods of compliance for paragraphs (a) and (b) 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.

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 paragraphs (c)(2) and (d) of this AD, 
the actions shall be done in accordance with Boeing Service Bulletin 
747-32-2190, Revision 4, dated October 26, 1989; and Boeing Alert 
Service Bulletin 747-32A2465, Revision 1, dated July 20, 2000; as 
applicable. 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 October 3, 2001.

    Issued in Renton, Washington, on August 20, 2001.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-21492 Filed 8-28-01; 8:45 am]
BILLING CODE 4910-13-U