[Federal Register Volume 68, Number 139 (Monday, July 21, 2003)]
[Rules and Regulations]
[Pages 42948-42950]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-17772]



[[Page 42948]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-55-AD; Amendment 39-13234; AD 2003-14-15]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-100, 747-100B, 747-
100B SUD, 747-200B, 747-200F, 747-200C, 747-300, 747-400, 747-400D, 
747-400F, and 747SR 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 inspections for cracking of the forward end clevis 
lugs of the flap track, and replacement of the flap track with a new 
flap track if necessary. That AD also currently provides for an 
optional modification of the forward end clevis lugs, which terminates 
the required inspections. This amendment expands the applicability of 
the existing AD, and requires new repetitive inspections for evidence 
of rotation or migration of the bushings or cracking of the lugs of the 
forward end clevis of the flap tracks that support the wing trailing 
edge flaps, corrective actions if necessary, and eventual 
accomplishment of a terminating action. These actions are necessary to 
prevent cracking and fracture of the forward end clevis of the flap 
track, which could result in reduced structural capability of the flap 
and reduced controllability of the airplane. This action is intended to 
address the identified unsafe condition.

DATES: Effective August 25, 2003.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of August 25, 2003.

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: Gary Oltman, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
917-6443; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 90-24-09, 
amendment 39-6815 (55 FR 48228, November 20, 1990), which is applicable 
to certain Boeing Model 747 series airplanes, was published in the 
Federal Register on December 2, 2002 (67 FR 71497). The action proposed 
to continue to require inspections for cracking of the forward end 
clevis lugs of the flap track, and replacement of the flap track with a 
new flap track if necessary. The action also provided for an optional 
modification of the forward end clevis lugs, which would terminate the 
required inspections. The action proposed to expand the applicability 
of the existing AD, require new repetitive inspections for evidence of 
rotation or migration of the bushings or cracking of the lugs of the 
forward end clevis of the flap tracks that support the wing trailing 
edge flaps, and require corrective actions if necessary. The action 
also proposed to require eventual accomplishment of a terminating 
action.

Comments

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

Request To Clarify Corrective Action

    One commenter notes that the procedures for the Terminating Action 
in part 2 of Boeing Service Bulletin 747-57-2307, Revision 1, dated 
January 17, 2002, include a magnetic particle inspection of the clevis 
bore of a machined flap track assembly. The commenter points out that 
no corrective action is specified if a crack is found, though the 
commenter assumes that the flap track must be replaced. The commenter 
states that both the service bulletin and proposed AD should specify a 
corrective action.
    We partially agree with the commenter. We note that, where the 
service bulletin specifies a magnetic particle inspection, the service 
bulletin refers to Boeing Standard Overhaul Practices Manual 20-20-01, 
Class A, Critical, for information pertaining to the inspection. We 
note that the acceptance criteria in that document do not allow 
cracking. Thus, a cracked flap track may not be used and must be 
replaced with a new flap track.
    However, we agree that we could clarify the need to replace the 
existing flap track with a new flap track if any cracking is found 
during the magnetic particle inspection that is included in the 
procedures for the terminating action required by this AD. Therefore, 
we have revised paragraph (h) of this final rule to specify that, if a 
crack is found during any inspection required by paragraph (d), (i), or 
(j) of this AD (or paragraph (e), (f), or (g)(2)(i) of this AD, as 
specified in paragraph (h) of the proposed AD), the cracked flap track 
must be replaced with a new flap track before further flight.

Explanation of Editorial Change

    We have revised paragraph (f) of this AD to make it clear that 
accomplishment of the terminating modification in paragraph (d) or (i) 
of this AD ends the repetitive inspections required by paragraph (f) of 
this AD.

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

Changes to 14 CFR Part 39/Effect on the Proposed AD

    On July 10, 2002, the FAA issued a new version of 14 CFR part 39 
(67 FR 47997, July 22, 2002), which governs the FAA's airworthiness 
directives system. The regulation now includes material that relates to 
altered products, special flight permits, and alternative methods of 
compliance. Because we have now included this material in part 39, we 
no longer need to include it in each individual AD. However, for 
clarity and consistency in this final rule, we have retained the 
language of the NPRM regarding that material.

Explanation of Change to Cost Impact

    After the proposed AD was issued, we reviewed the figures we use to 
calculate the labor rate to do the required actions. To account for 
various inflationary costs in the airline industry, we find it 
appropriate to increase the labor rate used in these calculations from 
$60 per work hour to $65 per work hour. The economic impact 
information, below, has been revised to reflect this increase in the 
specified hourly labor rate.

Cost Impact

    There are approximately 1,002 Model 747-100, 747-100B, 747-100B 
SUD, 747-200B, 747-200F, 747-200C, 747-

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300, 747-400, 747-400D, 747-400F, and 747SR series airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 219 
airplanes of U.S. registry will be affected by this AD.
    The actions that are currently required by AD 90-24-09 take 
approximately 2 work hours per airplane, at an average labor rate of 
$65 per work hour. Based on these figures, the cost impact of the 
currently required actions is estimated to be $130 per airplane, per 
inspection cycle.
    The new inspections that are required by this AD take approximately 
2 work hours per airplane, at an average labor rate of $65 per work 
hour. Based on these figures, the cost impact of the new inspections on 
U.S. operators is estimated to be $28,470, or $130 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, 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

0
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

0
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]

0
2. Section 39.13 is amended by removing amendment 39-6815 (55 FR 48228, 
November 20, 1990), and by adding a new airworthiness directive (AD), 
amendment 39-13234, to read as follows:

2003-14-15 Boeing: Amendment 39-13234. Docket 2002-NM-55-AD. 
Supersedes AD 90-24-09, Amendment 39-6815.

    Applicability: Model 747-100, 747-100B, 747-100B SUD, 747-200B, 
747-200F, 747-200C, 747-300, 747-400, 747-400D, 747-400F, and 747SR 
series airplanes; as listed in Boeing Service Bulletin 747-57-2307, 
Revision 1, dated January 17, 2002; 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 (k)(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 prevent cracking and fracture of the forward end clevis of 
the flap track, which could result in reduced structural capability 
of the flap and reduced controllability of the airplane, accomplish 
the following:

Restatement of Requirements of AD 90-24-09

Initial Inspection

    (a) For airplanes listed in Boeing Service Bulletin 747-57-2231, 
Revision 2, dated September 27, 1990: Perform a detailed inspection 
of the forward end clevis lugs of the flap tracks for evidence of 
cracking, according to Boeing Service Bulletin 747-57-2231, Revision 
2, dated September 27, 1990, and according to the following 
schedule:
    (1) For airplanes listed in Group 1 in the service bulletin: 
Perform the inspection at flap track positions 1 through 8 within 
the next 30 days after December 5, 1990 (the effective date of AD 
90-24-09, amendment 39-6815).
    (2) For airplanes listed in Group 2 in the service bulletin: 
Perform the inspection at flap track positions 1, 2, 7, and 8 prior 
to the later of the following:
    (i) Prior to the accumulation of 30,000 flight hours or 8 years 
after airplane delivery, whichever occurs first; or
    (ii) Within 120 days after December 5, 1990.
    (3) For airplanes listed in Group 3 in the service bulletin: 
Perform the inspection at flap track positions 1 through 8 prior to 
the later of the following:
    (i) Prior to the accumulation of 30,000 flight hours or 8 years 
after airplane delivery, whichever occurs first; or
    (ii) Within 120 days after December 5, 1990.

Flap Track Replacement

    (b) If cracking is found during any inspection required by 
paragraph (a) of this AD, replace the flap track prior to further 
flight, according to Boeing Service Bulletin 747-57-2231, Revision 
2, dated September 27, 1990.

Repetitive Inspections

    (c) If no cracking is found during any inspection required by 
paragraph (a) of this AD, repeat the inspection required by 
paragraph (a) of this AD at intervals not to exceed 300 flight 
cycles for Group 1 airplanes, and 1,200 flight cycles for Group 2 
and Group 3 airplanes, until paragraph (d), (e), or (i) of this AD 
has been done.

Optional Terminating Action

    (d) For airplanes listed in Boeing Service Bulletin 747-57-2231, 
Revision 2, dated September 27, 1990: Accomplishment of the 
modification of the forward end clevis lugs of the flap tracks as 
specified in Boeing Service Bulletin 747-57-2231, Revision 2, dated 
September 27, 1990, constitutes terminating action for the 
requirements of paragraphs (a), (c), (e), and (i) of this AD.

New Requirements of this AD

    Note 2: For the purposes of this AD, a detailed 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.''

Detailed Inspections

    (e) At the applicable compliance time specified in paragraph 
(e)(1) or (e)(2) of this AD, perform detailed inspections for 
evidence of rotation or migration of the bushings (including cracked 
or missing sealant around the bushing flange, or a gap between the 
bushing flange and the lug face)

[[Page 42950]]

or cracking of the lugs of the forward end clevis of the flap tracks 
that support the wing trailing edge flaps, according to Part 1 of 
the Work Instructions in Boeing Service Bulletin 747-57-2307, 
Revision 1, dated January 17, 2002.
    (1) For airplanes inspected before the effective date of this AD 
according to paragraph (a) of this AD: Do the inspection in 
paragraph (e) of this AD at the time specified in paragraph 
(e)(1)(i) or (e)(1)(ii) of this AD, as applicable. Doing this 
inspection terminates the requirements of paragraph (c) of this AD.
    (i) For airplanes listed in Group 1 of Boeing Service Bulletin 
747-57-2231, Revision 2: Inspect within 300 flight cycles after the 
most recent inspection per paragraph (a) or (c) of this AD.
    (ii) For airplanes listed in Group 2 or 3 of Boeing Service 
Bulletin 747-57-2231, Revision 2: Inspect within 1,200 flight cycles 
after the most recent inspection per paragraph (a) or (c) of this 
AD.
    (2) For airplanes not inspected before the effective date of 
this AD according to paragraph (a) of this AD: Do the inspection in 
paragraph (e) of this AD at the time specified in paragraph 
(e)(2)(i) or (e)(2)(ii) of this AD, whichever occurs later. This 
terminates the requirement to do paragraph (a) of this AD.
    (i) Within 8 years after the earlier of the date of issuance of 
the original Airworthiness Certificate or the date of issuance of 
the Export Certificate of Airworthiness, or before the accumulation 
of 30,000 total flight hours, whichever occurs first.
    (ii) Within 300 flight cycles or 120 days after the effective 
date of this AD, whichever occurs first.

Repetitive Inspections

    (f) If no evidence of migration or rotation of the bushings or 
cracking of the lugs is found during the inspection required by 
paragraph (e) of this AD: Repeat the inspections at the applicable 
repetitive interval specified in Figure 1 of Boeing Service Bulletin 
747-57-2307, Revision 1, dated January 17, 2002, until the 
terminating modification of paragraph (d) or (i) of this AD has been 
done.

Corrective Actions and Repetitive Inspections

    (g) If evidence of migration or rotation of the bushings is 
found during any inspection required by paragraph (e) or (f) of this 
AD, but no cracking is found: Do paragraph (g)(1) or (g)(2) of this 
AD, as applicable, according to Boeing Service Bulletin 747-57-2307, 
Revision 1, dated January 17, 2002.
    (1) For airplanes listed in Group 1 in the service bulletin and 
flap track numbers 3 and 6 on airplanes listed in Group 2 of the 
service bulletin: Before further flight, do the terminating 
modification in paragraph (i) of this AD, as specified in paragraph 
(i)(2) of this AD.
    (2) For airplanes other than those identified in paragraph 
(g)(1) of this AD: Before further flight, apply corrosion-inhibiting 
compound according to the service bulletin, and do paragraphs 
(g)(2)(i) and (g)(2)(ii) of this AD at the intervals specified in 
those paragraphs, until paragraph (d) or (i) of this AD is done. Do 
paragraph (i) of this AD at the applicable time specified in 
paragraph (i)(2) of this AD.
    (i) Repeat the inspections in paragraph (e) of this AD at the 
intervals specified in Figure 1 of the service bulletin.
    (ii) Apply corrosion-inhibiting compound according to the 
service bulletin at intervals not to exceed 200 flight cycles.

Replacement of Flap Track

    (h) If any cracking is found during any inspection required by 
paragraph (d), (e), (f), (g)(2)(i), (i), or (j) of this AD: Before 
further flight, replace the cracked flap track with a new flap 
track, according to Boeing Service Bulletin 747-57-2307, Revision 1, 
dated January 17, 2002. Replacement with a new flap track having a 
part number listed in the ``New Part Number'' column of the table 
under paragraph 2.E. of the service bulletin constitutes terminating 
action for the requirements of this AD for the replaced track.

Terminating Modification

    (i) At the applicable time specified in paragraph (i)(1) or 
(i)(2) of this AD: Do all actions (including but not limited to 
machining, performing magnetic particle inspections, and applying 
cadmium plating to the clevis bore and bushing) associated with 
replacing the bushings of the forward end clevis with new bushings 
with a higher interference fit on flap tracks 1, 2, 3, 4, 5, 6, 7, 
and 8; as applicable; according to Boeing Service Bulletin 747-57-
2307, Revision 1, dated January 17, 2002. This replacement 
terminates the requirements of this AD.
    (1) If no evidence of migration or rotation of the bushings or 
cracking of the lugs is found during any inspection required by 
paragraph (e) or (f) of this AD: Do the replacement within 8 years 
after the effective date of this AD.
    (2) If any evidence of bushing migration or rotation is found 
during any inspection required by paragraph (e) or (f) of this AD: 
Do the replacement at the applicable time specified in Figure 1 of 
the service bulletin.

Credit for Actions According to Previous Revision of Service 
Bulletin

    (j) Inspections, corrective actions, and terminating action done 
before the effective date of this AD according to Boeing Service 
Bulletin 747-57-2307, dated July 29, 1999, are considered acceptable 
for compliance with the corresponding action specified in this AD.

Alternative Methods of Compliance

    (k)(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. 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 
according to AD 90-24-09, amendment 39-6815, are approved as 
alternative methods of compliance with paragraphs (a), (b), (c), and 
(d) 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

    (l) 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

    (m) Unless otherwise specified in this AD, the actions shall be 
done in accordance with Boeing Service Bulletin 747-57-2231, 
Revision 2, dated September 27, 1990; and Boeing Service Bulletin 
747-57-2307, Revision 1, dated January 17, 2002; 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

    (n) This amendment becomes effective on August 25, 2003.

    Issued in Renton, Washington, on July 8, 2003.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-17772 Filed 7-18-03; 8:45 am]
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