AD 2005-10-17

[Federal Register Volume 70, Number 96 (Thursday, May 19, 2005)]
[Rules and Regulations]
[Pages 28797-28800]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 05-9875]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NM-214-AD; Amendment 39-14094; AD 2005-10-17]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 777-200 and -300 Series 
Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Boeing Model 777-200 and -300 series airplanes, 
that requires modification of the bolt holes of the lower side of the 
body splice t-chord common to the paddle fittings of the lower wing 
panel. The modification includes performing a high frequency eddy 
current inspection of the fastener holes for cracks, repairing the hole 
if necessary, and replacing the fasteners with new inconel bolts. This 
action is necessary to prevent fatigue cracks in the lower t-chord at 
the bolt holes common to the paddle fittings that could result in 
fractures of one or more of the t-chord segments, which could lead to 
detachment of the lower wing panel and consequent loss of the wing. 
This action is intended to address the identified unsafe condition.

DATES: Effective June 23, 2005.
    The incorporation by reference of a certain publication listed in 
the regulations is approved by the Director of the Federal Register as 
of June 23, 2005.

ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Airplanes, 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.

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) to include an airworthiness 
directive (AD) that is applicable to certain Boeing Model 777-200 and -
300 series airplanes was published in the Federal Register on June 16, 
2004 (69 FR 33595). That action proposed to require modification of the 
bolt holes of the lower side of the body splice t-chord common to the 
paddle fitting of the lower wing panel. The modification includes 
performing a high frequency eddy current inspection of the fastener 
hole for cracks, repairing the hole if necessary, and replacing the 
fasteners with new inconel bolts.

Comments

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

Agreement With Proposed Modification

    Two commenters generally agree with the proposal to mandate the 
modification specified in the proposed AD instead of allowing an option 
to accomplish repetitive inspections. One commenter notes that the work 
hours needed to do the modification are comparable to the work hours 
needed to do the inspection.

Request To Revise Compliance Times Based on ``Sliding Scale'' Equation

    One commenter, the manufacturer, requests that the compliance times 
specified in paragraph (a) of the proposed AD be revised to be based on 
a ``sliding scale'' equation. The commenter states that the ``sliding 
scale'' equation determines compliance times based on an evaluation of 
the total flight cycles associated with the total flight hours. The 
commenter notes that the compliance times specified in paragraph (a) of 
the proposed AD were found to be adversely affecting operators who use 
airplanes on long missions. The commenter states that some airplanes 
are reaching the 60,000 total flight-hour threshold before reaching 
8,000 total flight cycles. The commenter further contends that the 
cracks addressed in the proposed AD are largely a function of flight 
cycles, not flight hours, and that, for these airplanes, the proposed 
AD would mandate the modification before it is necessary.
    We agree with the commenter to revise the compliance times 
specified in paragraph (a) of the final rule. However, we do not agree 
with the compliance time based on a ``sliding scale'' equation proposed 
by the commenter. That proposed compliance time would expand the 
compliance envelope for airplanes utilized on long missions but would 
reduce the compliance time for airplanes near the 20,000 flight-cycle 
and 60,000 flight-hour compliance envelope.
    We held an ex-parte meeting with the commenter to discuss its 
proposed compliance time. The commenter presented data in support of a 
new ``sliding scale'' equation for the compliance time that differed 
from the equation proposed in the manufacturer's comment. The new 
proposed compliance time simply expanded the compliance time specified 
in the proposed AD. The new data were accepted and subsequently 
incorporated into Boeing Service Bulletin 777-57A0040, Revision 2, 
dated February 24, 2005. Boeing Service Bulletin 777-57A0040, Revision 
1, dated July 10, 2003, was referenced as the appropriate source of 
service information for accomplishing the proposed actions. Revision 2 
of the service bulletin contains the same actions for doing the 
modification as Revision 1 of the service bulletin.
    We have revised paragraph (a) of the final rule to reference 
Revision 2 of the

[[Page 28798]]

service bulletin as the appropriate source of service information for 
doing the actions, and we have revised paragraph (a)(1) of the final 
rule to specify the compliance times in the service bulletin. The 
service bulletin specifies the actions be done within approximately 
20,000 total flight cycles, or 80,000 total flight hours, as shown in 
Figure 1 of the service bulletin.
    We have also revised the applicability of the final rule to 
reference Revision 2 of the service bulletin. In addition, we added new 
paragraph (c) of the final rule to allow credit for actions done in 
accordance with Revision 1 of the service bulletin.

Request To Increase the Flight Hour Compliance Time

    Several commenters request that the flight-hour compliance time 
specified in paragraph (a)(1) of the proposed AD be increased from 
60,000 total flight hours to 65,000 total flight hours.
    One commenter notes that, when its airplanes reach the 60,000 total 
flight-hour threshold, the airplanes will have only 12,000 total flight 
cycles, which is well below the 20,000 total flight-cycle threshold. 
The commenter states that increasing the flight-hour compliance time 
will allow accomplishing the modification at 65,000 total flight hours, 
which leaves approximately 7,000 flight cycles remaining before 
reaching the 20,000 total flight cycle threshold. The commenter also 
points out that it concurs with Boeing that the premature 
accomplishment of the modification would decrease the fatigue life of 
the affected area. The commenter notes that an airplane's productive 
life may be decreased if there is premature accomplishment of the 
modification because fatigue cracks may occur earlier than on airplanes 
that do not accomplish the modification prematurely. The commenter 
contends that increasing the flight-hour threshold will prevent 
premature accomplishment of the modification for airplanes having a low 
number of flight cycles.
    One other commenter states that the issue addressed by the proposed 
AD is a fatigue concern and therefore the flight cycle compliance time 
is more relevant than the flight-hour compliance time. The commenter 
notes that Boeing is in agreement with the request to increase the 
compliance time to 65,000 flight hours. The commenter states that 
increasing the compliance time will allow it to accomplish the 
modification during heavy maintenance visits instead of light 
maintenance visits.
    Another commenter states that further studies may show 
justification for greater increases in the compliance times.
    We do not agree with the commenters' request to increase the 
flight-hour compliance time specified in paragraph (a)(1) of the final 
rule to 65,000 flight hours. The commenters did not provide data to 
substantiate that the change in compliance time would provide an 
acceptable level of safety. In addition, the manufacturer determined 
after further analysis that premature accomplishment of the 
modification is not an issue. However, as stated previously in the 
``Request to Revise Compliance Times Based on ``Sliding Scale'' 
Equation'' paragraph, we have revised the compliance time specified in 
paragraph (a)(1) of the final rule to refer to the compliance time 
specified in Revision 2 of Boeing Service Bulletin 777-57A0040. The 
revised compliance time extends the compliance time threshold for 
certain airplanes.
    In developing an appropriate compliance time for this action, we 
considered the urgency associated with the subject unsafe condition, 
the compliance times recommended by the manufacturer, and the practical 
aspect of accomplishing the required modification within a period of 
time that corresponds to the normal scheduled maintenance for most 
affected operators. In addition, according to the provisions of 
paragraph (d) of the final rule, we may approve requests to adjust the 
compliance time if the request includes data that substantiate that the 
new compliance time would provide an acceptable level of safety. No 
change is made to this final rule in this regard.

Request To Increase Flight Hour and Flight Cycle Compliance Time

    One commenter requests that the compliance times specified in 
paragraph (a)(1) of the proposed AD be revised to ``70,000 [total] 
flight hours or 10,000 [total] flight cycles, whichever comes first.'' 
The commenters state that this new compliance time would lessen the 
impact on operators that use high flight hour airplanes.
    We partially agree with the request to revise the compliance times 
in paragraph (a)(1) of the final rule. The commenter did not provide 
data to substantiate that reducing the flight cycle threshold and 
increasing the flight hour threshold would provide an acceptable level 
of safety, and therefore, we have not revised the final rule in this 
regard. However, as stated previously in the ``Request to Revise 
Compliance Times Based on ``Sliding Scale'' Equation'' paragraph, we 
have revised the compliance time specified in paragraph (a)(1) of the 
final rule to refer to the compliance time specified in Revision 2 of 
Boeing Service Bulletin 777-57A0040. Airplanes having 70,000 total 
flight hours and 10,000 total flight cycles would be compliant within 
the compliance time specified in Revision 2.

Request To Add Reference About the Early Accomplishment of the 
Modification

    One commenter states it is concerned that the proposed AD does not 
include reference to flag note 2 of Figure 1 of Boeing Service Bulletin 
777-57A0040, Revision 1, dated July 10, 2003, which states that ``the 
full benefit of the modification will not be realized if the 
modification is accomplished too early in the airplane life.'' The 
commenter notes that, if the modification is done early and then cracks 
are discovered later, there may be future regulatory action. The 
commenter contends this would create an unnecessary burden to operators 
that accomplish the actions in the proposed AD.
    We infer from the commenter's statement that it requests that a 
reference be added to the final rule regarding the early accomplishment 
of the modification as specified in Revision 1 of the service bulletin. 
However, as stated previously in the ``Request to Revise Compliance 
Times Based on ``Sliding Scale'' Equation'' paragraph, Revision 2 of 
the service bulletin is referenced as the appropriate source of service 
information for accomplishing the required actions in the final rule. 
Revision 2 of the service bulletin does not include flag note 2 of 
Figure 1 from Revision 1 of the service bulletin. After the 
manufacturer did further analysis, the manufacturer determined that the 
note is not necessary. We have not revised the final rule in this 
regard.

Request To Revise the Cost Impact

    One commenter states that actions specified in the proposed AD will 
take 200 work hours and that the materials will cost $24,000, for a 
total cost of $464,266 per airplane.
    We infer from the commenter's statement that it requests that the 
estimate be revised in the Cost Impact section of the final rule. We 
partially agree with the commenter to revise the Cost Impact section of 
the final rule. We have revised the work hour estimate in the final 
rule from approximately 34 work hours per airplane to 68 work hours per 
airplane. We do not agree to revise the work hour estimate to the 
commenter's work hour estimate of 200 work hours per airplane. The work 
hour

[[Page 28799]]

estimate in the final rule represents only the time necessary to 
perform the specific actions actually required by the final rule. The 
work hour estimate typically does not include incidental costs, such as 
the time required to gain access and close up, planning time, or time 
necessitated by other administrative actions. The commenter's estimate 
of $24,000 for materials is within the range specified in the Cost 
Impact section of the final rule, which specifies parts cost between 
approximately $21,686 and $24,803. We have not made a change to the 
parts cost estimate in the final rule in this regard.

Changes to Delegation Authority

    Boeing has received a Delegation Option Authorization (DOA). We 
have revised this final rule to delegate the authority to approve an 
alternative method of compliance for any repair required by this AD (if 
specifically authorized) to the Authorized Representative for the 
Boeing DOA Organization rather than the Designated Engineering 
Representative (DER).

Conclusion

    After careful review of the available data, including the comments 
noted above, we have determined that air safety and the public interest 
require the adoption of the rule with the changes previously described. 
These changes will neither increase the economic burden on any operator 
nor increase the scope of the AD.

Cost Impact

    There are approximately 262 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 73 airplanes of U.S. registry 
will be affected by this final rule, that it would take approximately 
68 work hours per airplane to accomplish the required modification, and 
that the average labor rate is $65 per work hour. Required parts will 
cost between approximately $21,686 and $24,803 per airplane. Based on 
these figures, the cost impact of the final rule on U.S. operators is 
estimated to be between $1,905,738 and $2,133, 279, or between $26,106 
and $29,223 per airplane.
    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.

Authority for This Rulemaking

    The FAA's authority to issue rules regarding aviation safety is 
found in Title 49 of the United States Code. Subtitle I, Section 106 
describes the authority of the FAA Administrator. Subtitle VII, 
Aviation Programs, describes in more detail the scope of the agency's 
authority.
    This rulemaking is promulgated under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this AD.

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:

2005-10-17 Boeing: Amendment 39-14094. Docket 2003-NM-214-AD.

    Applicability: Model 777-200 and -300 series airplanes, 
certificated in any category, as identified in Boeing Service 
Bulletin 777-57A0040, Revision 2, dated February 24, 2005.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent fatigue cracks in the lower t-chord at the bolt holes 
common to the paddle fittings that could result in fractures of one 
or more of the t-chord segments, which could lead to detachment of 
the lower wing panel and consequent loss of the wing, accomplish the 
following:

Modification of the Lower Paddle Fitting Bolt Holes/Fastener 
Replacement

    (a) At the later of the times specified in paragraphs (a)(1) and 
(a)(2) of this AD, modify the bolt holes of the lower side of the 
body splice t-chord common to the paddle fittings of the lower wing 
panel (includes performing a high frequency eddy current inspection 
of the fastener hole for cracks, repairing the hole if necessary, 
and replacing the fasteners with new inconel bolts) by accomplishing 
all of the actions specified in ``Part 2--Preventative 
Modification'' of the Work Instructions of Boeing Service Bulletin 
777-57A0040, Revision 2, dated February 24, 2005, except as provided 
by paragraph (b) of this AD. Any applicable repair must be 
accomplished before further flight.
    (1) At the time specified in Figure 1 of the service bulletin. 
Where the service bulletin refers to compliance times as flight 
hours and flight cycles, this AD refers to the compliance times as 
total flight hours and total flight cycles.
    (2) Within 1,500 days or 8,000 flight cycles after the effective 
date of this AD, whichever is first.
    (b) If any crack is found during the modification required by 
paragraph (a) of this AD, and the service bulletin specifies to 
contact Boeing for additional instructions: Before further flight, 
repair per a method approved by the Manager, Seattle Aircraft 
Certification Office (ACO), FAA; or according to data meeting the 
certification basis of the airplane approved by an Authorized 
Representative for the Boeing Delegation Option Authorization 
Organization who has been authorized by the Manager, Seattle ACO, to 
make those findings. For a repair method to be approved, the repair 
must meet the certification basis of the airplane, and the approval 
must specifically refer to this AD.

[[Page 28800]]

Actions Accomplished According to Previous Issue of Service Bulletin

    (c) Actions accomplished before the effective date of this AD 
according to Boeing Service Bulletin 777-57A0040, Revision 1, dated 
July 10, 2003, are considered acceptable for compliance with the 
corresponding action specified in this AD.

Alternative Methods of Compliance

    (d) In accordance with 14 CFR 39.19, the Manager, Seattle ACO, 
is authorized to approve alternative methods of compliance for this 
AD.

Incorporation by Reference

    (e) Unless otherwise specified in this AD, the actions shall be 
done in accordance with Boeing Service Bulletin 777-57A0040, 
Revision 2, dated February 24, 2005. 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. To get copies of the service 
information, go to Boeing Commercial Airplanes, 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 National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, call (202) 741-6030, or go to: <a href="http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html">http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html</a>.

Effective Date

    (f) This amendment becomes effective on June 23, 2005.

    Issued in Renton, Washington, on May 9, 2005.
Jeffrey E. Duven,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-9875 Filed 5-18-05; 8:45 am]
BILLING CODE 4910-13-P