[Federal Register Volume 72, Number 18 (Monday, January 29, 2007)]
[Proposed Rules]
[Pages 3956-3958]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-1321]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
 
 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
 ========================================================================
 

  Federal Register / Vol. 72, No. 18 / Monday, January 29, 2007 / 
Proposed Rules  

[[Page 3956]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-27042; Directorate Identifier 2006-NM-225-AD]
RIN 2120-AA64


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

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

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain Boeing Model 777-200, -300, and -300ER series airplanes. 
This proposed AD would require installing Teflon sleeving under the 
clamps of the wire bundles routed along the fuel tank boundary 
structure, and cap sealing certain penetrating fasteners of the main 
and center fuel tanks. This proposed AD results from fuel system 
reviews conducted by the manufacturer. We are proposing this AD to 
prevent electrical arcing on the fuel tank boundary structure or inside 
the fuel tanks, which could result in a fire or explosion.

DATES: We must receive comments on this proposed AD by March 15, 2007.

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.
     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.
    Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for the service information identified in this 
proposed AD.

FOR FURTHER INFORMATION CONTACT: Margaret Langsted, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone 
(425) 917-6500; 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 in the ADDRESSES section. Include the docket number ``FAA-2007-
27042; Directorate Identifier 2006-NM-225-AD'' at the beginning 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 received 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 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 may review DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
may visit http://dms.dot.gov.

Examining the Docket

    You may 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 Docket Management System 
receives them.

Discussion

    The FAA has examined the underlying safety issues involved in fuel 
tank explosions on several large transport airplanes, including the 
adequacy of existing regulations, the service history of airplanes 
subject to those regulations, and existing maintenance practices for 
fuel tank systems. As a result of those findings, we issued a 
regulation titled ``Transport Airplane Fuel Tank System Design Review, 
Flammability Reduction and Maintenance and Inspection Requirements'' 
(66 FR 23086, May 7, 2001). In addition to new airworthiness standards 
for transport airplanes and new maintenance requirements, this rule 
included Special Federal Aviation Regulation No. 88 (``SFAR 88,'' 
Amendment 21-78, and subsequent Amendments 21-82 and 21-83).
    Among other actions, SFAR 88 requires certain type design (i.e., 
type certificate (TC) and supplemental type certificate (STC) holders 
to substantiate that their fuel tank systems can prevent ignition 
sources in the fuel tanks. This requirement applies to type design 
holders for large turbine-powered transport airplanes and for 
subsequent modifications to those airplanes. It requires them to 
perform design reviews and to develop design changes and maintenance 
procedures if their designs do not meet the new fuel tank safety 
standards. As explained in the preamble to the rule, we intended to 
adopt airworthiness directives to mandate any changes found necessary 
to address unsafe conditions identified as a result of these reviews.
    In evaluating these design reviews, we have established four 
criteria intended to define the unsafe conditions associated with fuel 
tank systems that require corrective actions. The percentage of 
operating time during which fuel tanks are exposed to flammable 
conditions is one of these criteria. The other three criteria address 
the failure types under evaluation: Single failures, single failures in 
combination with a latent condition(s),

[[Page 3957]]

and in-service failure experience. For all four criteria, the 
evaluations included consideration of previous actions taken that may 
mitigate the need for further action.
    We have determined that the actions identified in this AD are 
necessary to reduce the potential of ignition sources inside fuel 
tanks, which, in combination with flammable fuel vapors, could result 
in fuel tank explosions and consequent loss of the airplane.
    We have received a report that seven operators discovered pinched 
insulation or wiring damage under the clamps of wire bundles routed 
along the fuel tank boundary structure of Model 777 airplanes. In some 
cases, bare wires were discovered. Also, it was determined that certain 
penetrating fasteners of the main and center fuel tanks were not 
adequately sealed against fault currents induced by short circuits or 
lightning strikes, and that certain other fasteners of the center fuel 
tank had not been sealed during production. During a short circuit 
event or lightning strike, damaged wires could cause electrical arcing 
on the fuel tank boundary structure or conduct electrical current to 
unsealed fasteners that penetrate the fuel tanks, which could create 
arcing inside the fuel tanks. This condition, if not corrected, could 
result in a fire or explosion.

Relevant Service Information

    We have reviewed the following service information:
     Boeing Alert Service Bulletin 777-57A0050, dated January 
26, 2006 (applicable to Model 777-200, -200ER, -300, and -300ER 
airplanes), which describes procedures for installing Teflon sleeving 
under the clamps of the power feeder wire bundles routed along certain 
fuel tank boundary structure and for cap sealing selected fasteners of 
the main and center fuel tanks;
     Boeing Alert Service Bulletin 777-57A0051, dated May 15, 
2006 (applicable to Model 777-200 and -300 airplanes), which describes 
procedures for cap sealing the spoilers numbers 5 and 10 outboard hinge 
fitting fasteners in the main fuel tanks; and
     Boeing Alert Service Bulletin 777-57A0057, dated August 7, 
2006 (applicable to Model 777-200, -300, and -300ER airplanes), which 
describes procedures for cap sealing certain fasteners in the center 
fuel tanks that were not sealed during production.
    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. For this reason, we are proposing this AD, 
which would require accomplishing the actions specified in the service 
information described previously.

Clarification of Model Number Reference

    Although Alert Service Bulletin 777-57A0050 refers to ``Model 777-
200ER'' airplanes, this is a European designation that does not apply 
to airplanes of U.S. registry. Therefore, the applicability of this 
proposed AD will not specify Model 777-200ER airplanes. However, U.S. 
operators should take any reference to Model 777-200ER airplanes in 
Alert Service Bulletin 777-57A0050 as applicable to Model 777-200 
airplanes as designated by the type certificate data sheet.

Costs of Compliance

    There are about 446 airplanes of the affected design in the 
worldwide fleet. This proposed AD would affect about 123 airplanes of 
U.S. registry. The following table provides the estimated costs for 
U.S. operators to comply with this proposed AD at an estimated labor 
rate of $80 per work hour.

                                 Estimated Costs for Airplanes of U.S. Registry
----------------------------------------------------------------------------------------------------------------
                                                      Work                   Cost per    Number of
                  Airplane group                     hours     Parts cost    airplane    airplanes    Fleet cost
----------------------------------------------------------------------------------------------------------------
Group 1..........................................        278       $2,241      $24,481           19     $465,139
Group 2..........................................        358        2,241       30,881          104    3,211,624
----------------------------------------------------------------------------------------------------------------

    Currently, there are no affected Group 3 airplanes on the U.S. 
Register. However, if a Group 3 airplane is imported and placed on the 
U.S. Register in the future, the required actions would take about 480 
work hours, at an average labor rate of $80 per work hour. Required 
parts would cost about $2,241. Based on these figures, we estimate the 
cost of this AD to be $40,641 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 would not have federalism 
implications under Executive Order 13132. This proposed AD would 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 and placed it in the AD docket. 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, Safety.

[[Page 3958]]

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 Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2007-27042; Directorate Identifier 2006-NM-
225-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by March 15, 
2007.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 777-200, -300, and -300ER 
series airplanes, certificated in any category; as identified in the 
service bulletins specified in Table 1 of this AD.

                                           Table 1.--Service Bulletins
----------------------------------------------------------------------------------------------------------------
     Boeing Alert Service Bulletin--              Revision level--                        Dated--
----------------------------------------------------------------------------------------------------------------
777-57A0050.............................  Original.......................  January 26, 2006.
777-57A0051.............................  Original.......................  May 15, 2006.
777-57A0057.............................  Original.......................  August 7, 2006.
----------------------------------------------------------------------------------------------------------------


    Note 1: Although Alert Service Bulletin 777-57A0050 refers to 
``Model 777-200ER'' airplanes, this is a European designation that 
does not apply to airplanes of U.S. registry. Therefore, the 
applicability of this AD will not specify Model 777-200ER airplanes. 
However, U.S. operators should take any reference to Model 777-200ER 
airplanes in Alert Service Bulletin 777-57A0050 as applicable to 
Model 777-200 airplanes as designated by the type certificate data 
sheet.

Unsafe Condition

    (d) This AD results from fuel system reviews conducted by the 
manufacturer. We are issuing this AD to prevent electrical arcing on 
the fuel tank boundary structure or inside the main and center fuel 
tanks, which could result in a fire or explosion.

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.

Corrective Actions

    (f) Within 60 months after the effective date of this AD, 
install Teflon sleeving under the clamps of the wire bundles routed 
along the fuel tank boundary structure, and cap seal certain 
penetrating fasteners of the fuel tanks as applicable, in accordance 
with the Accomplishment Instructions of the applicable service 
bulletins specified in Table 1 of this AD.

Alternative Methods of Compliance (AMOCs)

    (g)(1) The Manager, Seattle Aircraft Certification Office, FAA, 
has the authority to approve AMOCs for this AD, if requested in 
accordance with the procedures found in 14 CFR 39.19.
    (2) Before using any AMOC approved in accordance with Sec.  
39.19 on any airplane to which the AMOC applies, notify the 
appropriate principal inspector in the FAA Flight Standards 
Certificate Holding District Office.

    Issued in Renton, Washington, on January 18, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E7-1321 Filed 1-26-07; 8:45 am]
BILLING CODE 4910-13-P