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

[Federal Register Volume 70, Number 177 (Wednesday, September 14, 2005)]
[Rules and Regulations]
[Pages 54242-54244]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-17985]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-20475; Directorate Identifier 2004-NM-157-AD; 
Amendment 39-14250; AD 2005-18-10]
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: The FAA is adopting a new airworthiness directive (AD) for 
certain Boeing Model 777-200 and -300 series airplanes. This AD 
requires modification of the splice plate assemblies installed under 
the floor panels at the forward and aft edges of the cabin aisle. This 
AD results from reports of cracking of the aluminum splice plates under 
the floor panels in the cabin aisle. We are issuing this AD to prevent 
loss of the capability of the cabin floor and seat track structure to 
support the airplane interior inertia loads under emergency landing 
conditions. Loss of this support could lead to galley or seat 
separation from attached restraints, which could result in blocking of 
the emergency exits and consequent injury to passengers and crew.

DATES: This AD becomes effective October 19, 2005.
    The incorporation by reference of a certain publication listed in 
the AD is approved by the Director of the Federal Register as of 
October 19, 2005.

ADDRESSES: For service information identified in this AD, contact 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-
2207.
    Docket: The AD docket contains the proposed AD, comments, and any 
final disposition. You can examine the AD docket on the Internet at 
http://dms.dot.gov, or in person at the Docket Management Facility 
office between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif Building at the U.S. 
Department of Transportation, 400 Seventh Street SW, room PL-401, 
Washington, DC. This docket number is FAA-2005-20475; the directorate 
identifier for this docket is 2004-NM-157-AD.

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: The FAA proposed to amend 14 CFR part 39 
with an AD for certain Boeing Model 777-200, -200ER, and -300 series 
airplanes. That action, published in the Federal Register on March 3, 
2005 (70 FR 10337), proposed to require modification of the splice 
plate assemblies installed under the floor panels at the forward and 
aft edges of the cabin aisle.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments that have been 
submitted on the proposed AD.

Request To Add Optional Inspection Program

    One commenter asks that, in addition to the terminating action 
specified in the proposed AD, an optional inspection program be 
implemented to do inspections of the most affected areas, with 
replacement or repair of affected parts on attrition. The commenter 
states that such an inspection should be added as a compliance option, 
in lieu of a full modification, or in conjunction with a longer 
compliance time. The commenter adds that, in order to accomplish the 
modification, access to some locations will be difficult; therefore, 
consideration should be given to adding inspections to extend the 
compliance time. The commenter suggests adding to the proposed AD an 
internal general visual inspection of the floor splice plates that are 
visible from the forward and aft pit. In addition, the commenter 
recommends inspecting from above for flexing and ``clicking'' noises 
commonly associated with splice plate cracking of the remaining areas 
located in the overwing section and not viewable from the pits. The 
commenter suggests that the inspections be done at intervals no longer 
than 48 months apart, and that a full general visual inspection of all 
affected splice plates be done within a 72-month period to allow for 
normal maintenance cycles that facilitate the inspection.
    The commenter states that it was instrumental in identifying and 
reporting cracked splice plate discrepancies to the airplane 
manufacturer in December 1999. The reports brought about changes 
addressing the subject issue that were

[[Page 54243]]

added to both the structural repair and airplane maintenance manuals 
for Boeing Model 777 airplanes. The commenter adds that its findings 
were significant enough to justify creating a specific maintenance 
program that contained procedures for finding and addressing the 
cracking in most affected areas. The inspections revealed an 
overwhelming propensity for cracking in the aisle nearest the passenger 
entry doors 1L and 2L. The commenter concludes that the approach of 
inspecting aisle and entry floor panels at 3C intervals has been highly 
effective in managing this issue.
    We do not agree with the commenter's request. We understand that 
there are splice plates in some areas that can be inspected from below, 
but there are several inaccessible areas where difficulty gaining 
access would not allow for an inspection. The inspection methods 
suggested by the commenter are not reliable for those inaccessible 
areas. Further, inspection of other splice plates from below is of 
questionable reliability in determining the onset of cracking. Also, 
partially cracked splice plates and splice plates with repairs of 
unknown reliability are not acceptable for addressing the unsafe 
condition. For these reasons, we have determined that the modification 
required by the AD is the most effective method of addressing the 
identified unsafe condition. We note that the 60-month compliance time 
should allow for modification during normal maintenance cycles for most 
affected operators. However, under the provisions of paragraph (h) of 
this AD, if adequate technical justification is provided, affected 
operators may request approval of an alternative method of compliance 
(AMOC).

Request To Consider Alternative Action

    One commenter states that it has paperwork in place to accomplish 
the proposed AD, but has some concerns about the methods proposed for 
solution to the described problem. The commenter notes that it appears 
that the unsafe condition specified in the proposed AD is a design 
flaw, though the airplane manufacturer has not accepted the 
responsibility for a resolution. The commenter concludes that, because 
of that fact, the manufacturer should re-address the problem and come 
up with a secondary solution that would not require replacement of the 
splice straps.
    We do not agree with the commenter. The airplane manufacturer has 
developed an improved splice plate to correct the unsafe condition. The 
FAA has determined that the proposed modification (replacement of the 
splice straps) is necessary to address the unsafe condition specified 
in the proposed AD, which is due to cracking of the aluminum splice 
plates. We did not include the option of accomplishing inspections 
because access to many of the affected areas is limited, so an 
inspection would not provide reliable results. Therefore, replacing the 
splice straps with new, improved splice straps is the most effective 
way to address the unsafe condition. Additionally, the proposed AD 
allows a 60-month compliance time to allow for accomplishing the 
modification during regular maintenance visits. However, under the 
provisions of paragraph (h) of this AD, if adequate technical 
justification is provided, affected operators may request approval of 
AMOC.

Request To Change Costs of Compliance Section

    One commenter states that, because the cause of the unsafe 
condition specified in the proposed AD is a design flaw that has not 
been resolved, the commenter must bear the cost of 48 work hours per 
airplane to accomplish the proposed modification. The commenter adds 
that gaining access to some locations to accomplish the modification 
will be difficult, and estimates that this modification would cost 
approximately $200,000 for labor and $308,000 for material for its 
entire fleet. The commenter does not provide a specific request.
    We infer that the commenter is asking us to change the ``Costs of 
Compliance'' section of this AD. We do not agree. The estimate of 28 
work hours per airplane is based on the best data available to date, 
and is consistent with the manufacturer's estimate contained in the 
service bulletin. The cost impact figures discussed in AD rulemaking 
actions represent only the time necessary to perform the specific 
actions actually required by the AD. We recognize that in accomplishing 
the requirements of any AD, operators may incur incidental costs in 
addition to the direct costs. However, the cost analysis in AD 
rulemaking actions 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. Because incidental costs 
may vary significantly from operator to operator, they are almost 
impossible to calculate. We have not changed the AD in this regard.

Explanation of Change to Proposed AD

    The applicability in the proposed AD addresses ``Boeing Model 777-
200, -200ER, and -300 series airplanes.'' We inadvertently included 
Model 777-200ER series airplanes, which are not specified on the type 
certificate data sheet and are encompassed within the Model 777-200 
series. Our intent is that the AD apply to certain Boeing Model 777-200 
and -300 series airplanes; therefore, we have changed the applicability 
in this AD accordingly.

Conclusion

    We have carefully reviewed the available data, including the 
comments that have been received, and determined that air safety and 
the public interest require adopting the AD with the change described 
previously. This change will neither increase the economic burden on 
any operator nor increase the scope of the AD.

Costs of Compliance

    There are about 330 airplanes of the affected design in the 
worldwide fleet. This AD affects about 131 airplanes of U.S. registry. 
The modification will take about 28 work hours per airplane, at an 
average labor rate of $65 per work hour. Required parts will cost 
between $4,717 and $9,099 per airplane. Based on these figures, the 
estimated cost of the AD for U.S. operators is between $856,347 and 
$1,430,389, or between $6,537 and $10,919 per airplane.

Authority for this Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. 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.
    We are issuing this rulemaking 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 
rulemaking action.

Regulatory Findings

    We have determined that this AD will not have federalism 
implications under Executive Order 13132. This AD 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

[[Page 54244]]

responsibilities among the various levels of government.
    For the reasons discussed above, I certify that this AD:
    (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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this AD. See the ADDRESSES section for a location to 
examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 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. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

2005-18-10 Boeing: Amendment 39-14250. Docket No. FAA-2005-20475; 
Directorate Identifier 2004-NM-157-AD.

Effective Date

    (a) This AD becomes effective October 19, 2005.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 777-200 and -300 series 
airplanes, certificated in any category; as identified in Boeing 
Special Attention Service Bulletin 777-53-0042, dated April 15, 
2004.

Unsafe Condition

    (d) This AD results from reports of cracking of the aluminum 
splice plates under the floor panels in the cabin aisle. We are 
issuing this AD to prevent loss of the capability of the cabin floor 
and seat track structure to support the airplane interior inertia 
loads under emergency landing conditions. Loss of this support could 
lead to galley or seat separation from attached restraints, which 
could result in blocking of the emergency exits and consequent 
injury to passengers and crew.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Modification

    (f) Within 60 months after the effective date of this AD: Except 
as provided by paragraph (g) of this AD, modify the splice plate 
assemblies installed under the floor panels at the forward and aft 
edges of the cabin aisle (including replacement of damaged fasteners 
with new fasteners) in accordance with the Accomplishment 
Instructions of Boeing Special Attention Service Bulletin 777-53-
0042, dated April 15, 2004.
    (g) The referenced service bulletin recommends marking the 
service bulletin number on the top of the floor panel assembly, but 
this AD does not require that action.

Alternative Methods of Compliance (AMOCs)

    (h) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested in 
accordance with the procedures found in 14 CFR 39.19.

Material Incorporated by Reference

    (i) You must use Boeing Special Attention Service Bulletin 777-
53-0042, dated April 15, 2004, to perform the actions that are 
required by this AD, unless the AD specifies otherwise. The Director 
of the Federal Register approved the incorporation by reference of 
this document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. 
Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for a copy of this service information. You 
may review copies at the Docket Management Facility, U.S. Department 
of Transportation, 400 Seventh Street SW., Room PL-401, Nassif 
Building, Washington, DC; on the Internet at http://dms.dot.gov; or 
at the National Archives and Records Administration (NARA). For 
information on the availability of this material at the NARA, call 
(202) 741-6030, or go to http://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Renton, Washington, on September 2, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-17985 Filed 9-13-05; 8:45 am]
BILLING CODE 4910-13-P

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