[Federal Register Volume 68, Number 161 (Wednesday, August 20, 2003)]
[Rules and Regulations]
[Pages 50061-50064]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-20986]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-178-AD; Amendment 39-13280; AD 2003-17-06]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-100, 747SP, and 747SR 
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 747-100, 747SP, and 747SR series 
airplanes, that requires repetitive inspections to find fatigue 
cracking between the seal ribs of the front spar web of the wing and 
outboard of the outboard seal rib to front spar station inboard (FSSI) 
711, and repair of cracked structure. This AD also provides for an 
optional modification of a certain area. This action is necessary to 
find and fix fatigue cracking between the seal ribs of the front spar 
web of the wing and outboard of the outboard seal rib to FSSI 711, 
which could result in fuel leakage into the area of the inboard 
engines, and consequent increased risk of a fire. This action is 
intended to address the identified unsafe condition.

DATES: Effective September 24, 2003.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of September 24, 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: 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) 917-6421; fax (425) 
917-6590.

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 747-100, 
747SP, and 747SR series airplanes, was published in the Federal 
Register on February 4, 2003 (68 FR 5610). That action proposed to 
require repetitive inspections to find fatigue cracking between the 
seal ribs of the front spar web of the wing, and repair of cracked 
structure. That action also proposed to provide for an optional 
modification of a certain area.

Comments

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

Request To Revise Compliance Time

    The commenter requests that we revise compliance time information 
in paragraphs (a) and (b) of the proposed AD to make the wording of the 
inspection threshold and grace period more specific. The commenter 
specifically asks that we add a new paragraph (a)(2) and revise 
paragraph (b)(1) of the proposed AD to include the words ``Within 18 
months of the effective date of this AD for all airplanes that have 
exceeded the total flight cycles or total flight hours * * *.'' The 
commenter states that this change is necessary so that operators of 
airplanes that have exceeded the thresholds specified in the service 
bulletin will know how much time they have to accomplish the initial 
inspection.
    We do not concur with the commenter's request. Paragraph (b)(1) of 
this AD specifically refers to Tables 1 through 3 of Figure 1 of the 
Accomplishment Instructions or Appendix A of the referenced service 
bulletin as the appropriate source of the compliance time for the 
applicable initial or post-modification inspection. Paragraph (a) of 
this AD is intended to clarify the grace period stated in the service 
bulletin. We find that affected operators should be readily able to 
determine the applicable compliance time, as clarified by paragraph (a) 
of this AD. No change is necessary in this regard.

Request To Clarify Repair Instructions

    The commenter requests that we revise paragraph (c) of the proposed 
AD to add a reference to corrosion or damage that may be found during 
the inspections or the optional modification specified in paragraph (d) 
of the proposed AD. The commenter states

[[Page 50062]]

that operators may find corrosion or damage during the required 
inspections, or fastener holes may be damaged during accomplishment of 
the optional modification.
    We do not concur with the commenter's request to add a reference to 
corrosion or damage. The inspections described in the referenced 
service bulletin and required by this AD are intended only to reveal 
cracking related to the identified unsafe condition. If any corrosion 
or damage is found during accomplishment of an action required by this 
AD, an operator would be required--regardless of AD direction--to 
correct the corrosion or damage to ensure that the airplane is operated 
in an airworthy condition as required by the Federal Aviation 
Regulations.
    Related to this, we infer that the rationale for the commenter's 
request is to ensure that repairs of corrosion and other damage may be 
approved by a delegated Designated Engineering Representative (DER). We 
do not agree that any change is necessary to meet the commenter's 
intent. If corrosion or damage is found, and the Manager of the Seattle 
Aircraft Certification Office (ACO) has authorized a Boeing Company DER 
to approve an alternative method of compliance for this AD, then the 
Boeing Company DER may approve a repair if it is structurally adequate 
per the FAA's delegation letter.
    We concur, however, with the commenter's request to revise 
paragraph (c) of this final rule to add a reference to the optional 
modification. We note that paragraph (c) of the proposed AD states that 
it applies to any cracking found during any inspection required by the 
AD. This would include any inspection specified in the procedures for 
the optional modification. We find that adding the reference requested 
by the commenter may clarify that any cracking found during the 
optional modification must be repaired before further flight. Thus, for 
clarification, we have revised paragraph (c) of this AD to specify that 
the repair provisions in that paragraph apply to any cracking found 
during an inspection required by this AD, including cracking found 
during accomplishment of the modification specified in paragraph (d) of 
this AD.

Request To Clarify Inspection Threshold

    The commenter requests that we revise paragraph (d) of the proposed 
AD to clarify that, if the optional modification is accomplished, the 
threshold for the repetitive inspections of Zone B is extended to the 
post-modification threshold specified in Tables 1 through 3 of Figure 1 
of the service bulletin. The proposed AD does not include the words 
``post-modification'' before the word ``threshold.'' The commenter does 
not state any justification for its request.
    We infer that the commenter is concerned that, because there are 
other thresholds specified in the service bulletin, operators may be 
confused about the new threshold for the repetitive inspections of Zone 
B. We concur that this clarification may be helpful and have revised 
paragraph (d) of this AD accordingly.

Request To Revise Inspection Terminology, Add Inspection Definition

    The commenter requests that we revise paragraph (b) of the proposed 
AD to refer to a ``detailed visual inspection'' instead of a ``detailed 
inspection.'' The commenter also requests that we add an AD note 
defining a ``detailed visual inspection.'' The commenter points out 
that this note has appeared in other ADs.
    We do not concur with the commenter's request to revise the 
inspection terminology. The term ``detailed visual inspection'' was 
changed to ``detailed inspection'' in Revision 2003.1 of the Air 
Transport Association of America (ATA)/MSG-3 document, ``ATA Operator/
Manufacturer Scheduled Maintenance Development.'' We find that this 
terminology should be readily understood by all affected operators, and 
no change to the terminology is necessary.
    We do concur with the commenter's request to add the standard AD 
note defining a ``detailed inspection.'' This note was inadvertently 
omitted from the proposed AD. Therefore, we have added a new Note 2 to 
this AD and renumbered subsequent notes accordingly.

Request To Clarify Area of Inspection

    The commenter requests that we revise the ``Summary'' section of 
the proposed AD to clarify the area of inspection. The commenter states 
that the statement that the proposed AD would require, ``repetitive 
inspections to find fatigue cracking between the seal ribs of the front 
spar web of the wing'' is not accurate. The commenter states that 
inspections also extend outboard of the outboard seal rib to front spar 
station inboard (FSSI) 713.
    We concur with the intent of the commenter's request; however, we 
find that the subject inspection area extends to FSSI 711, not FSSI 713 
as stated by the commenter. We have revised the ``Summary'' of this 
final rule accordingly. We find that this does not expand the scope of 
the proposed AD because paragraph (b) of the proposed AD states that 
the inspections must be accomplished ``per the Accomplishment 
Instructions'' of Boeing Special Attention Service Bulletin 747-57-
2313, Revision 1, dated February 21, 2002. The ``Summary'' section of a 
proposed AD is intended to provide only a very general description of 
the proposed requirements, while the preamble more completely describes 
the proposed requirements.

Request To Revise Preamble

    The commenter requests that we make the following changes to the 
preamble of the proposed AD:
    [sbull] In the ``Discussion'' section of the proposed AD, identify 
the model on which the 24-inch crack in the front spar web of the right 
wing was found as a Boeing Model 747-200 series airplane, not a Model 
747-100 series airplane.
    [sbull] In the ``Discussion'' section of the proposed AD, state 
that the cracks originated from a hole common to a rib post on the 
front spar at FSSI 655.70, not FSSI 656.
    [sbull] In the ``Related Rulemaking'' section of the proposed AD, 
state that both AD 90-17-18, amendment 39-6702 (55 FR 33279, August 15, 
1990), and AD 95-12-26, amendment 39-9279 (60 FR 34107, June 30, 1995), 
refer to Boeing Service Bulletin 747-57A2259 as the appropriate source 
of information for actions required by those ADs.
    We partially agree with the commenter's requests:
    [sbull] We agree that the original report of cracking was on a 
Boeing Model 747-200 series airplane, not on a Model 747-100 as stated 
in the proposed AD. The unsafe condition associated with this AD is 
addressed on Model 747-200 series airplanes by the rulemaking action 
associated with Rules Docket No. 2001-NM-228-AD, which we issued as a 
notice of proposed rulemaking on February 24, 2003 (68 FR 10185, March 
4, 2003).
    [sbull] Section 1.C., ``Reason,'' of Boeing Special Attention 
Service Bulletin 747-57-2313, Revision 1, states that the hole from 
which the cracking originated was common to a rib post on the front 
spar at FSSI 656. Thus, the proposed AD is consistent with the service 
bulletin, and the change requested by the commenter is not necessary.
    [sbull] AD 95-12-26 supersedes AD 90-17-18. Thus, the proposed AD 
should have referred to the requirements of AD 95-12-26 instead of AD 
90-17-18.
    Regardless of these issues, neither the ``Discussion'' nor the 
``Related Rulemaking'' section is restated in this

[[Page 50063]]

final rule. Thus, no change to the final rule is necessary in this 
regard.

Explanation of Additional Change to Proposed AD

    We have revised the service bulletin citation throughout this final 
rule to delete references to Appendices A and B of Boeing Special 
Attention Service Bulletin 747-57-2313, Revision 1. However, in 
paragraphs (b)(1), (b)(2), and (d) of this AD, the references to 
Appendix A of Boeing Special Attention Service Bulletin 747-57-2313, 
Revision 1, have been retained because those paragraphs refer 
specifically to the inspection thresholds and intervals specified in 
Appendix A of the service bulletin. Also, we have retained the 
reference to Appendices A and B in the citation of the original issue 
of Boeing Special Attention Service Bulletin 747-57-2313, dated April 
19, 2001, because those appendices are outside the numbered pages of 
that service bulletin.

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 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 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. However, for clarity and consistency in this final rule, we 
have retained the language of the NPRM regarding that material.

Change to Labor Rate Estimate

    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 109 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 59 airplanes of U.S. registry 
will be affected by this AD, that it will take approximately 25 work 
hours per airplane to accomplish the required inspections, and that the 
average labor rate is $65 per work hour. Based on these figures, the 
cost impact of this AD on U.S. operators is estimated to be $95,875, or 
$1,625 per airplane, per inspection cycle.
    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. 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.
    Should an operator elect to do the optional modification of Zone B, 
it would take approximately 480 work hours to accomplish at an average 
labor rate of $65 per work hour. Parts cost would be approximately 
$16,652. Based on these figures, the cost impact of the proposed 
modification is estimated to be $47,852 per airplane.

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 adding the following new airworthiness 
directive:
2003-17-06 Boeing: Amendment 39-13280. Docket 2001-NM-178-AD.
    Applicability: Model 747-100, 747SP, and 747SR series airplanes, 
as listed in Boeing Special Attention Service Bulletin 747-57-2313, 
Revision 1, dated February 21, 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 (f) 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 fatigue cracking between the seal ribs of the 
front spar web of the wing and outboard of the outboard seal rib to 
front spar station inboard 711, which could result in fuel leakage 
into the area of the inboard engines, and consequent increased risk 
of a fire; accomplish the following:

Compliance Times

    (a) Where the compliance times in the service bulletin specify a 
compliance time interval calculated ``after the initial release of 
this service bulletin,'' this AD requires compliance within the 
interval specified in the service bulletin ``after the effective 
date of this AD.'' In addition, where the compliance time for the 
initial inspection in Tables 1 through 3 of Figure 1 of the service 
bulletin specifies ``flight hours,'' this AD requires a compliance 
time of ``total flight hours.''

Initial and Repetitive Inspections

    (b) Do detailed, high frequency eddy current and ultrasonic 
inspections to find cracking of the front spar web of the wing as 
specified in paragraphs (b)(1) and (b)(2) of this AD, per the 
Accomplishment Instructions of Boeing Special Attention

[[Page 50064]]

Service Bulletin 747-57-2313, Revision 1, dated February 21, 2002.
    (1) Do the applicable initial or post-modification inspection at 
the times specified for the inspections in Tables 1 through 3 of 
Figure 1 of the Accomplishment Instructions or Appendix A of the 
service bulletin.
    (2) After doing the applicable initial or post-modification 
inspection specified in paragraph (b)(1) of this AD: Repeat that 
inspection within the applicable intervals specified in Tables 1 
through 3 of Figure 1 of the Accomplishment Instructions or Appendix 
A of the service bulletin.

    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.''

Repair

    (c) If any cracking is found during any inspection required by 
this AD, including any inspection performed during accomplishment of 
the optional modification per paragraph (d) 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 who has been 
authorized by the Manager, Seattle ACO, to make such findings. For a 
repair method to be approved, the approval must specifically 
reference this AD.

Optional Modification

    (d) Accomplishment of the modification of Zone B per Part 2 of 
the Accomplishment Instructions of Boeing Special Attention Service 
Bulletin 747-57-2313, Revision 1, dated February 21, 2002, would 
extend the threshold recommended in Tables 1 through 3 of Figure 1 
of the Accomplishment Instructions or Appendix A of the service 
bulletin for the repetitive inspections of Zone B, to the new post-
modification threshold specified in Tables 1 through 3 of Figure 1 
of the service bulletin.

Previously Accomplished Inspections and Modifications

    (e) Inspections and modifications done before the effective date 
of this AD per Boeing Special Attention Service Bulletin 747-57-
2313, including Appendices A and B, dated April 19, 2001, are 
considered acceptable for compliance with the applicable actions 
specified in this AD.

    Note 3: Boeing Special Attention Service Bulletin 747-57-2313, 
Revision 1, dated February 21, 2002, recommends prior or concurrent 
accomplishment of Boeing Alert Service Bulletins 747-57A2259, 747-
57A2266, and 747-54A2159. The modifications in those service 
bulletins are required by AD 95-10-16, amendment 39-9233.

Alternative Methods of Compliance

    (f) 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.

    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 Permit

    (g) 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

    (h) Unless otherwise specified in this AD, the actions shall be 
done in accordance with Boeing Special Attention Service Bulletin 
747-57-2313, Revision 1, dated February 21, 2002. 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

    (i) This amendment becomes effective on September 24, 2003.

    Issued in Renton, Washington, on August 12, 2003.
Kyle L. Olsen,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-20986 Filed 8-19-03; 8:45 am]
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