[Federal Register Volume 70, Number 41 (Thursday, March 3, 2005)]
[Proposed Rules]
[Pages 10337-10339]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-4073]


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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]
RIN 2120-AA64


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

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

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain Boeing Model 777-200, -200ER, and -300 series airplanes. 
This proposed AD would require modification of the splice plate 
assemblies installed under the floor panels at the forward and aft 
edges of the cabin aisle. This proposed AD is prompted by reports of 
cracking of the aluminum splice plates under the floor panels in the 
cabin aisle. We are proposing 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: We must receive comments on this proposed AD by April 18, 2005.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401, 
Washington, DC 20590.
     By fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this proposed AD, contact 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-
2207.
    You can examine the contents of this AD docket on the Internet at 
http://dms.dot.gov, or in person at the Docket Management Facility, 
U.S. Department of Transportation, 400 Seventh Street, SW., room PL-
401, on the plaza level of the Nassif Building, 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: 

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2005-20475; 
Directorate Identifier 2004-NM-157-AD'' in the subject line of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments submitted by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD. Using the search function of 
that Web site, anyone can find and read the

[[Page 10338]]

comments in any of our dockets, including the name of the individual 
who sent the comment (or signed the comment on behalf of an 
association, business, labor union, etc.). You can review DOT's 
complete Privacy Act Statement in the Federal Register published on 
April 11, 2000 (65 FR 19477-78), or you can visit http://dms.dot.gov.

Examining the Docket

    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 DOT 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after the DMS receives them.

Discussion

    We have received reports indicating that cracking of the aluminum 
splice plates installed at the forward and aft edges under the floor 
panels in the cabin was found during routine maintenance on several 
Model 777 series airplanes. The floor panels are attached with 
fasteners that pass through the floor panel and connect to a threaded 
nut plate on the splice plate. The airplanes had accumulated between 
1,375 and 14,614 total flight cycles. Analysis shows that the cracking 
of the splice plates is due to repeated bending from frequent traffic 
in the cabin aisle. This condition, if not corrected, could result in 
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.

Relevant Service Information

    We have reviewed Boeing Special Attention Service Bulletin 777-53-
0042, dated April 15, 2004. The service bulletin describes procedures 
for modification of the splice plate assemblies under the floor panels 
at the forward and aft edges of the cabin aisle. The modification 
involves replacing the existing aluminum splice plate assemblies with 
new fiberglass laminate assemblies; and marking the service bulletin 
number on the top of the floor panel. The modification also includes 
replacing any damaged fasteners with new fasteners. Accomplishing the 
actions specified in the service information is intended to adequately 
address the unsafe condition.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other airplanes 
of this same type design. Therefore, we are proposing this AD, which 
would require accomplishing the actions specified in the service 
information described previously, except as discussed under 
``Differences Between the Proposed AD and Service Bulletin.''

Differences Between the Proposed AD and Service Bulletin

    The service bulletin recommends accomplishing the modification at 
the next scheduled heavy maintenance check, not to exceed 72 months 
from the service bulletin release date. We have determined that, 
because maintenance schedules vary among operators, and in order to 
address the unsafe condition in a timely manner, this proposed AD would 
require compliance within 60 months after the effective date of this 
AD. In developing an appropriate compliance time for this proposed AD, 
we considered not only the manufacturer's recommendation, but the 
degree of urgency associated with addressing the subject unsafe 
condition, the average utilization of the affected fleet, and the time 
necessary to perform the modification. In light of all of these 
factors, we find a compliance time of 60 months for completing the 
modification to be warranted, in that it represents an appropriate 
interval of time for affected airplanes to continue to operate without 
compromising safety.
    The applicability of the service bulletin inadvertently excluded 
Boeing Model 777-200ER series airplanes. Therefore, this proposed AD 
includes a requirement that the actions specified in the service 
bulletin be accomplished on those airplanes. This requirement would 
ensure that the actions specified in the service bulletin, and required 
by this proposed AD, are accomplished on all affected airplanes.
    The service bulletin also recommends marking the service bulletin 
number on the top of the floor panel assembly, but this proposed AD 
would not require that action. We find that, with a variety of marking 
methods and panel locations, this marking could not be accurately 
verified.
    These differences have been coordinated with the manufacturer.

Costs of Compliance

    There are about 330 airplanes of the affected design in the 
worldwide fleet. This proposed AD would affect about 131 airplanes of 
U.S. registry. The proposed modification would take about 28 work hours 
per airplane, at an average labor rate of $65 per work hour. Required 
parts would cost between $4,717 and $9,099 per airplane. Based on these 
figures, the estimated cost of the proposed 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 proposed AD will not have federalism 
implications under Executive Order 13132. This proposed 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 responsibilities among the various levels of government.
    For the reasons discussed above, I certify that the proposed 
regulation:
    1. Is not a ``significant regulatory action'' under Executive Order 
12866;
    2. Is not a ``significant rule'' under the 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 proposed AD. See the ADDRESSES section for a location 
to examine the regulatory evaluation.

[[Page 10339]]

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

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

Boeing: Docket No. FAA-2005-20475; Directorate Identifier 2004-NM-
157-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this AD action by April 18, 2005.

Affected ADs

    (b) None.

Applicability

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

Unsafe Condition

    (d) This AD was prompted by 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 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 proposed 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.

    Issued in Renton, Washington, on February 22, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-4073 Filed 3-2-05; 8:45 am]
BILLING CODE 4910-13-P