[Federal Register Volume 70, Number 76 (Thursday, April 21, 2005)]
[Proposed Rules]
[Pages 20724-20726]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-7997]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-21023; Directorate Identifier 2004-NM-262-AD]
RIN 2120-AA64


Airworthiness Directives; Airbus Model A320 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 Airbus Model A320 series airplanes. This proposed AD would 
require installing insulator and cable ties to the electrical cables of 
the S routes at the gaps in the raceway in the wing trailing edge and 
the wing tip and wing root areas. This proposed AD is prompted by the 
results of fuel system reviews conducted by the manufacturer. We are 
proposing this AD to prevent injection of high voltage current into the 
low voltage wiring that passes through the fuel tanks, which could 
result in a possible fuel tank explosion.

DATES: We must receive comments on this proposed AD by May 23, 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,

[[Page 20725]]

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 
Airbus, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France.
    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-2005-21023; the directorate identifier for this docket is 
2004-NM-262-AD.

FOR FURTHER INFORMATION CONTACT: Tim Dulin, Aerospace Engineer, 
International Branch, ANM-116, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-2141; fax (425) 227-1149.

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-2005-21023; 
Directorate Identifier 2004-NM-262-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 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 our 
docket 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 can review the 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

    The FAA has examined the underlying safety issues involved in 
recent 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'' (67 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 
another latent condition(s), 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.
    The Joint Aviation Authorities (JAA) has issued a regulation that 
is similar to SFAR 88. (The JAA is an associated body of the European 
Civil Aviation Conference (ECAC) representing the civil aviation 
regulatory authorities of a number of European States who have agreed 
to co-operate in developing and implementing common safety regulatory 
standards and procedures.) Under this regulation, the JAA stated that 
all members of the ECAC that hold type certificates for transport 
category airplanes are required to conduct a design review against 
explosion risks.
    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.
    The Direction G[eacute]n[eacute]rale de l'Aviation Civile (DGAC), 
which is the airworthiness authority for France, notified us that an 
unsafe condition may exist on certain Airbus Model A320 series 
airplanes. The DGAC advises that review of electrical installation on 
an in-service airplane has shown that insulation was not installed on 
the S cable routes of the wing trailing edge at all the gaps between 
raceways. Lack of insulation could lead to the injection of high 
voltage current from the M cable routes into the low voltage wiring S 
cable routes that pass through the fuel tanks. This condition, if not 
corrected, could result in a possible fuel tank explosion.

Relevant Service Information

    Airbus has issued Service Bulletin A320-24-1062, Revision 05, dated 
June 27, 2002. The service bulletin describes procedures for installing 
insulator and cable ties to the electrical cables of the S routes at 
the gaps in the raceway of the wing trailing edge and the wing tip and 
wing root areas. Accomplishing the actions specified in the service 
information is intended to adequately address the unsafe condition. The 
DGAC mandated the service information and issued French airworthiness 
directive F-2004-173, dated October 27, 2004, to ensure the continued 
airworthiness of these airplanes in France.

FAA's Determination and Requirements of the Proposed AD

    This airplane model is manufactured in France and is type 
certificated for operation in the United States under the provisions of 
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and 
the applicable bilateral airworthiness agreement. Pursuant to this 
bilateral airworthiness agreement, the DGAC has kept the FAA informed

[[Page 20726]]

of the situation described above. We have examined the DGAC's findings, 
evaluated all pertinent information, and determined that we need to 
issue an AD for products of this type design that are certificated for 
operation in the United States.
    Therefore, we are proposing this AD, which would require 
accomplishing the actions specified in the service information 
described previously, except as discussed under ``Difference Between 
the Proposed AD and French Airworthiness Directive.''

Difference Between the Proposed AD and French Airworthiness Directive

    The applicability of French airworthiness directive F-2004-173, 
dated October 27, 2004, excludes airplanes that have accomplished 
Airbus Service Bulletin A320-24-1062, Revision 05, dated June 27, 2002, 
in service. However, we have not excluded those airplanes in the 
applicability of this proposed AD; rather, this proposed AD includes a 
requirement to accomplish the actions specified in that service 
bulletin. This requirement would ensure that the actions specified in 
the service bulletin and required by this proposed AD are accomplished 
on all affected airplanes. Operators must continue to operate the 
airplane in the configuration required by this proposed AD unless an 
alternative method of compliance is approved. This difference has been 
coordinated with the DGAC.

Costs of Compliance

    This proposed AD would affect about 54 airplanes of U.S. registry. 
The proposed actions would take about 35 work hours per airplane, at an 
average labor rate of $65 per work hour. Required parts would cost 
about $0 per airplane. Based on these figures, the estimated cost of 
the proposed AD for U.S. operators is $122,850, or $2,275 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. 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.

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):

Airbus: Docket No. FAA-2005-21023; Directorate Identifier 2004-NM-
262-AD.

Comments Due Date

    (a) The Federal Aviation Administration must receive comments on 
this AD action by May 23, 2005.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Airbus Model A320 series airplanes, 
certificated in any category, except those modified in production by 
Airbus Modification 22626.

Unsafe Condition

    (d) This AD was prompted by the results of fuel system reviews 
conducted by the manufacturer. We are issuing this AD to prevent 
injection of high voltage current into the low voltage wiring that 
passes through the fuel tanks, which could result in a possible fuel 
tank 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.

Modification

    (f) Within 60 months after the effective date of this AD, 
install insulator and cable ties to the electrical cables of the S 
routes at the gaps in the raceway in the wing trailing edge and the 
wing tip and wing root areas, in accordance with Airbus Service 
Bulletin A320-24-1062, Revision 05, dated June 27, 2002.

Alternative Methods of Compliance (AMOCs)

    (g) The Manager, International Branch, ANM-116, Transport 
Airplane Directorate, FAA, has the authority to approve AMOCs for 
this AD, if requested in accordance with the procedures found in 14 
CFR 39.19.

Related Information

    (h) French airworthiness directive F-2004-173, dated October 27, 
2004, also addresses the subject of this AD.

    Issued in Renton, Washington, on April 13, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-7997 Filed 4-20-05; 8:45 am]
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