Airworthiness Directives; Boeing Model 747 Series Airplanes

[Federal Register Volume 66, Number 142 (Tuesday, July 24, 2001)]
[Rules and Regulations]
[Pages 38365-38367]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-18139]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-331-AD; Amendment 39-12337; AD 2001-15-03]
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 all Boeing Model 747 series airplanes, that 
currently requires repetitive inspections to detect cracking of the 
forward and aft inner chords and the splice fitting of the forward 
inner chord of the station 2598 bulkhead, and repair, if necessary. 
This amendment adds repetitive inspections of an expanded inspection 
area, which ends the inspections specified in the existing AD. This 
amendment also limits the applicability of the existing AD. This 
amendment is prompted by reports indicating that fatigue cracking was 
found on airplanes that had accumulated fewer total flight cycles than 
the threshold specified in the existing AD. The actions specified by 
this AD are intended to detect and correct fatigue cracking of the 
forward and aft inner chords, the frame support, and the splice fitting 
of the forward inner chord of the upper corner of the station 2598 
bulkhead, which could result in reduced structural capability of the 
bulkhead and the inability of the structure to carry horizontal 
stabilizer flight loads.

DATES: Effective August 28, 2001.
    The incorporation by reference of Boeing Alert Service Bulletin 
747-53A2427, Revision 2, October 5, 2000, as listed in the regulations, 
is approved by the Director of the Federal Register, as of August 28, 
2001.
    The incorporation by reference of Boeing Alert Service Bulletin 
747-53A2427, dated December 17, 1998; and Boeing Alert Service Bulletin 
747-53A2427, Revision 1, dated October 28, 1999; as listed in the 
regulations, was approved previously by the Director of the Federal 
Register as of June 5, 2000 (65 FR 25281, May 1, 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: 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) by superseding AD 2000-08-21, 
amendment 39-11707 (65 FR 25281, May 1, 2000), which is applicable to 
all Boeing Model 747 series airplanes, was published in the Federal 
Register on April 19, 2001 (66 FR 20111). The action proposed to 
continue to require repetitive inspections to detect cracking of the 
forward and aft inner chords and the splice fitting of the forward 
inner chord of the station 2598 bulkhead, and repair, if necessary. The 
action also proposed to add repetitive inspections of an expanded 
inspection area, which would end the inspections specified in the 
existing AD, and to limit the applicability of the existing AD.

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 1,115 Model 747 series 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.
    The high frequency eddy current (HFEC) inspection that currently is 
required by AD 2000-08-21 takes approximately 2 work hours per airplane 
to accomplish, at an average labor rate of $60 per work hour. Based on 
these figures, the cost impact of this inspection is estimated to be 
$120 per airplane.
    The detailed visual inspection that currently is required by AD 
2000-08-21 takes approximately 2 work hours per airplane to accomplish, 
at an average labor rate of $60 per work hour. Based on these figures, 
the cost impact of this inspection is estimated to be $120 per 
airplane, per inspection cycle.
    The HFEC inspections that are required by this new AD will take 
approximately 2 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Based on these figures, the cost 
impact of this inspection is estimated to be $120 per airplane, per 
inspection cycle.
    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,

[[Page 38366]]

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 39-11707 (65 FR 
25281, May 1, 2000) and by adding a new airworthiness directive (AD), 
amendment 39-12337, to read as follows:

2001-15-03  Boeing: Amendment 39-12337. Docket 2000-NM-331-AD. 
Supersedes AD 2000-08-21, Amendment 39-11707.

    Applicability: Model 747 series airplanes, line numbers 1 
through 1307 inclusive, 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 (g)(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 cracking of the forward and aft inner 
chords, the frame support, and the splice fitting of the forward 
inner chord of the upper corner of the station 2598 bulkhead, which 
could result in reduced structural capability of the bulkhead and 
the inability of the structure to carry horizontal stabilizer flight 
loads, accomplish the following:

Restatement of Requirements of AD
2000-08-21

Initial Inspection

    (a) Prior to the accumulation of 13,000 total flight cycles, or 
within 1,000 flight cycles after June 5, 2000 (the effective date of 
AD 2000-08-21, amendment 39-11707), whichever occurs later: 
Accomplish the requirements specified in paragraphs (a)(1) and 
(a)(2) of this AD.
    (1) Perform a high frequency eddy current inspection (HFEC) to 
detect cracking of the forward and aft inner chords of the station 
2598 bulkhead, in accordance with Boeing Alert Service Bulletin 747-
53A2427, dated December 17, 1998; or in accordance with Figure 2, 
Steps 1 and 2, of Boeing Alert Service Bulletin 747-53A2427, 
Revision 1, dated October 28, 1999.
    (2) Perform an HFEC inspection to detect cracking of the splice 
fitting along the upper and lower attachment to the forward inner 
chord of the station 2598 bulkhead, as shown in Figure 2, Detail A, 
of Boeing Alert Service Bulletin 747-53A2427, dated December 17, 
1998; or in accordance with Figure 2, Step 3, of Boeing Alert 
Service Bulletin 747-53A2427, Revision 1, dated October 28, 1999.

    Note 2: Operators should note that, although the splice fitting 
is NOT highlighted in Figure 2, Detail A, of Boeing Alert Service 
Bulletin 747-53A2427, dated December 17, 1998, as it is in Figure 2 
of Boeing Alert Service Bulletin 747-53A2427, Revision 1, dated 
October 28, 1999, the inspection required by paragraph (a)(2) of 
this AD must still be accomplished.

Repetitive Inspections

    (b) Within 3,000 flight cycles after accomplishment of the 
inspections required by paragraph (a) of this AD: Accomplish the 
inspections specified in paragraphs (b)(1) and (b)(2) of this AD. 
Repeat the inspections thereafter at intervals not to exceed 3,000 
flight cycles.
    (1) Perform a detailed visual inspection to detect cracking of 
the forward and aft inner chords of the station 2598 bulkhead, in 
accordance with Boeing Alert Service Bulletin 747-53A2427, dated 
December 17, 1998; or in accordance with Figure 3, Steps 1 and 2, of 
Boeing Alert Service Bulletin 747-53A2427, Revision 1, dated October 
28, 1999.

    Note 3: 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.''

    (2) Perform a detailed visual inspection to detect cracking of 
the splice fitting along the upper and lower attachment to the 
forward inner chord of the station 2598 bulkhead, as shown in Figure 
3, Detail A, of Boeing Alert Service Bulletin 747-53A2427, dated 
December 17, 1998; or in accordance with Figure 3, Step 3, of Boeing 
Alert Service Bulletin 747-53A2427, Revision 1, dated October 28, 
1999.

    Note 4: Operators should note that, although the splice fitting 
is NOT highlighted in Figure 3, Detail A, of Boeing Alert Service 
Bulletin 747-53A2427, dated December 17, 1998, as it is in Figure 3 
of Boeing Alert Service Bulletin 747-53A2427, Revision 1, dated 
October 28, 1999, the inspections required by paragraph (b)(2) of 
this AD must still be accomplished.

Repair

    (c) If any cracking is detected during the inspections required 
by paragraph (a)(1) or (b)(1) of this AD, prior to further flight, 
repair in accordance with Boeing Alert Service Bulletin 747-53A2427, 
dated December 17, 1998, Revision 1, dated October 28, 1999, or 
Revision 2, dated October 5, 2000; except as provided by paragraph 
(d) of this AD.
    (d) If any cracking is detected during the inspections required 
by paragraph (a)(2) or (b)(2) of this AD, or the alert service 
bulletin specifies that the manufacturer may be contacted for 
disposition of certain repair conditions, prior to further flight, 
repair in accordance with a method approved by the Manager, Seattle 
Aircraft Certification Office (ACO); or in accordance with 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.

New Requirements of This AD

Repetitive Inspections

    (e) Do a surface HFEC inspection of the forward and aft inner 
chords, the frame support, and the splice fitting of the forward 
inner chord of the upper corner of the station 2598 bulkhead to find 
cracking, in accordance with Boeing Alert Service Bulletin 747-
53A2427, Revision 2, dated October 5, 2000; at the latest of the 
times specified in paragraphs (e)(1) and (e)(2) of this AD, as 
applicable. Repeat the inspection after that at intervals not to 
exceed 1,500 flight cycles. Doing these inspections ends the 
inspections required by paragraphs (a) and (b) of this AD.
    (1) For airplanes having line numbers 1 through 1241 inclusive:
    (i) Before the accumulation of 6,000 total flight cycles.

[[Page 38367]]

    (ii) Within 500 flight cycles after the effective date of this 
AD.
    (iii) If the inspections specified in paragraph (a) or (b) of 
this AD were done before the effective date of this AD: Within 1,500 
flight cycles after accomplishment of the last inspection required 
by paragraph (a) or (b) of this AD, as applicable.
    (2) For airplanes having line numbers 1242 through 1307 
inclusive:
    (i) Before the accumulation of 16,000 total flight cycles.
    (ii) Within 500 flight cycles after the effective date of this 
AD.
    (iii) If the inspections specified in paragraph (a) or (b) of 
this AD were done before the effective date of this AD: Within 1,500 
flight cycles after accomplishment of the last inspection required 
by paragraph (a) or (b) of this AD, as applicable.

Repair

    (f) If any cracking is found during the inspections required by 
paragraph (e) of this AD, before further flight, repair in 
accordance with Boeing Alert Service Bulletin 747-53A2427, Revision 
2, dated October 5, 2000; except where the alert service bulletin 
specifies that the manufacturer may be contacted for disposition of 
certain repair conditions, before further flight, repair in 
accordance with a method approved by the Manager, Seattle ACO; or in 
accordance with 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.

Alternative Methods of Compliance

    (g)(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 per 
AD 2000-08-21, amendment 39-11707, are approved as alternative 
methods of compliance with paragraphs (c) and (d) of this AD.

    Note 5: 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

    (h) 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

    (i) Except as provided by paragraphs (d) and (f) of this AD, the 
actions shall be done in accordance with Boeing Alert Service 
Bulletin 747-53A2427, dated December 17, 1998; Boeing Alert Service 
Bulletin 747-53A2427, Revision 1, dated October 28, 1999; or Boeing 
Alert Service Bulletin 747-53A2427, Revision 2, dated October 5, 
2000; as applicable.
    (1) The incorporation by reference of Boeing Alert Service 
Bulletin 747-53A2427, Revision 2, dated October 5, 2000, is approved 
by the Director of the Federal Register as of August 28, 2001.
    (2) The incorporation by reference of Boeing Alert Service 
Bulletin 747-53A2427, dated December 17, 1998; and Boeing Alert 
Service Bulletin 747-53A2427, Revision 1, dated October 28, 1999; 
was approved previously by the Director of the Federal Register as 
of June 5, 2000 (65 FR 25281, May 1, 2000).
    (3) 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

    (j) This amendment becomes effective on August 28, 2001.

    Issued in Renton, Washington, on July 13, 2001.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-18139 Filed 7-23-01; 8:45 am]
BILLING CODE 4910-13-P

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