[Federal Register Volume 64, Number 105 (Wednesday, June 2, 1999)]
[Proposed Rules]
[Pages 29607-29608]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-13876]



[[Page 29607]]

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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-270-AD]
RIN 2120-AA64


Airworthiness Directives; Airbus Model A319, A320, and A321 
Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Airbus Model A319, A320, 
and A321 series airplanes. This proposal would require modification of 
the 90VU electronics rack umbrellas, the 91VU upper shelf assembly, the 
cockpit drain circuit, and the electrical wire routing above the 90VU 
electronics rack. This proposal is prompted by issuance of mandatory 
continuing airworthiness information by a foreign civil airworthiness 
authority. The actions specified by the proposed AD are intended to 
prevent damage to computer electrical connectors due to ingress of 
water into the avionics bay, which could result in malfunctioning of 
the avionics computers.

DATES: Comments must be received by July 2, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-270-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except 
Federal holidays.
    The service information referenced in the proposed rule may be 
obtained from Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707 
Blagnac Cedex, France. This information may be examined at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: Norman B. Martenson, Manager, 
International Branch, ANM-116, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-2110; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications shall identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 98-NM-270-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules 
Docket No. 98-NM-270-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The Direction Generale de l'Aviation Civile (DGAC), which is the 
airworthiness authority for France, has notified the FAA that an unsafe 
condition may exist on certain Airbus Model A319, A320, and A321 series 
airplanes. The DGAC advises that it has received reports of water 
dripping into the avionics bay. Analysis by the manufacturer has shown 
that the computers in the avionics bay may not be adequately protected 
from ingress of water. This condition, if not corrected, could result 
in damage to computer electrical connectors due to ingress of water 
into the avionics bay, and consequent malfunctioning of the avionics 
computers.

Related AD's

    The FAA has issued AD 98-20-04, amendment 39-10770 (63 FR 50129, 
September 21, 1998), which requires replacing certain toilet rinse 
valves with modified rinse valves.
    The FAA also has issued AD 99-02-03, amendment 39-10992 (64 FR 
2552, January 15, 1999), which requires installation of a rubber strip 
and replacement of connection sheets and the seal retainer on the 
avionics compartment access door with new parts; and installation of 
drip pans and additional drain gutters on the avionics racks.

Explanation of Relevant Service Information

    Airbus has issued Service Bulletin A320-25-1186, Revision 01, dated 
September 23, 1998, which describes procedures for modification of the 
90VU electronics rack umbrellas, the 91VU upper shelf assembly, the 
cockpit drain circuit, and the electrical wire routing above the 90VU 
electronics rack. Accomplishment of modifications specified in the 
service bulletin is intended to adequately address the identified 
unsafe condition. The DGAC classified this service bulletin as 
mandatory and issued French airworthiness directive 98-178-115(B), 
dated May 6, 1998, in order to assure the continued airworthiness of 
these airplanes in France.

FAA's Conclusions

    These airplane models are manufactured in France and are 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 
of the situation described above. The FAA has examined the findings of 
the DGAC, reviewed all available information, and determined that AD 
action is necessary for products of this type design that are 
certificated for operation in the United States.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design registered 
in the United States, the proposed AD would require accomplishment of 
the actions specified in the service bulletin described previously.

Cost Impact

    The FAA estimates that 140 Airbus Model A319, A320, and A321 series 
airplanes of U.S. registry would be affected by this proposed AD, that 
it

[[Page 29608]]

would take approximately 19 work hours per airplane to accomplish the 
proposed actions, and that the average labor rate is $60 per work hour. 
Required parts would be supplied by the manufacturer at no cost to the 
operators. Based on these figures, the cost impact of the proposed AD 
on U.S. operators is estimated to be $159,600, or $1,140 per airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the proposed requirements of 
this AD action, and that no operator would accomplish those actions in 
the future if this AD were not adopted.

Regulatory Impact

    The regulations proposed herein would not have substantial direct 
effects 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, in 
accordance with Executive Order 12612, it is determined that this 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this 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) if promulgated, 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 copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
part 39 of the Federal Aviation Regulations (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. Section 39.13 is amended by adding the following new 
airworthiness directive:

Airbus Industrie: Docket 98-NM-270-AD.

    Applicability: Models A319, A320, and A321 series airplanes on 
which Airbus Modification 25995 has not been accomplished, 
certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
otherwise modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (b) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent damage to computer electrical connectors due to 
ingress of water into the avionics bay, which could result in 
malfunctioning of the avionics computers, accomplish the following:

Modification

    (a) Within 2 years after the effective date of this AD, modify 
the 90VU electronics rack umbrellas, the 91VU upper shelf assembly, 
the cockpit drain circuit, and the electrical wire routing above the 
90VU electronics rack; in accordance with Airbus Service Bulletin 
A320-25-1186, Revision 01, dated September 23, 1998.

    Note 2: Accomplishment of the modification required by paragraph 
(a) of this AD in accordance with Airbus Service Bulletin A320-25-
1186, dated December 1, 1997, prior to the effective date of this 
AD, is considered acceptable for compliance with the requirements of 
this AD.

Alternative Methods of Compliance

    (b) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, International Branch, ANM-116, FAA, 
Transport Airplane Directorate. Operators shall submit their 
requests through an appropriate FAA Principal Maintenance Inspector, 
who may add comments and then send it to the Manager, International 
Branch, ANM-116.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the International Branch, ANM-116.

Special Flight Permits

    (c) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.

    Note 4: The subject of this AD is addressed in French 
airworthiness directive 98-178-115(B), dated May 6, 1998.

    Issued in Renton, Washington, on May 21, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-13876 Filed 6-1-99; 8:45 am]
BILLING CODE 4910-13-P