[Federal Register Volume 63, Number 65 (Monday, April 6, 1998)]
[Proposed Rules]
[Pages 16709-16711]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-8904]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-67-AD]
RIN 2120-AA64


Airworthiness Directives; Airbus Model A320 and A321 Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Airbus Model A320 and A321 
series airplanes. This proposal would require modification of the slat 
and flap control computer (SFCC) in the aft electronics rack. This 
proposal is prompted by issuance of mandatory continuing airworthiness 
information by

[[Page 16710]]

a foreign civil airworthiness authority. The actions specified by the 
proposed AD are intended to prevent failure of the SFCC caused by 
computer software anomalies or contamination by conductive dust. This 
condition, if not corrected, could result in uncommanded slat 
retraction during takeoff and consequent insufficient wing lift 
available to complete a successful takeoff.

DATES: Comments must be received by May 6, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-67-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-67-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-67-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The Direction Genorale de l'Aviation Civile (DGAC), which is the 
airworthiness authority for France, notified the FAA that an unsafe 
condition may exist on certain Airbus Model A320 and A321 series 
airplanes. The DGAC advises that, during the takeoff of a Model A320 
series airplane, the slat and flap control computer (SFCC) incorrectly 
interpreted the prior failure of a rotary switch in the Command Sensor 
Unit (CSU) as an out-of-detent condition of the flap control lever. 
Consequently, the SFCC commanded the slats to retract to position 0, 
contrary to the pilot's commanded position 1. In addition, the DGAC 
advises that it has received reports in which, during operation on 
Model A321 series airplanes, the SFCC failed because conductive dust 
from the air conditioning system had contaminated the SFCC system.
    The SFCC on certain Model A320 series airplanes is similar in 
design to that on Model A321 series airplanes; therefore, both models 
may be subject to the same unsafe condition. The failure of the SFCC, 
if not corrected, could result in uncommanded slat retraction during 
takeoff and consequent insufficient wing lift available to complete a 
successful takeoff.

Explanation of Relevant Service Information

    Airbus has issued Service Bulletin A320-27-1096, dated March 14, 
1996, and Revision 01, dated January 14, 1998, which describes 
procedures for modification of the SFCC 1 and SFCC 2 in the aft 
electronics rack on Model A320 series airplanes. This modification 
involves replacement of SFCC 1 and SFCC 2 with improved parts and 
modification of the SFCC software to correct anomalies.
    In addition, Airbus has issued Service Bulletin A320-27-1103, dated 
June 14, 1996, which describes procedures for modification of the SFCC 
1 and SFCC 2 in the aft electronics rack on Model A321 series 
airplanes. This modification involves replacement of SFCC 1 and SFCC 2 
with improved parts, installation of a dust shield, and modification of 
the coding of the polarizing pins on the ARINC 600 plug on the rack of 
the SFCC 1 and SFCC 2.
    Accomplishment of the actions specified in the service bulletins is 
intended to adequately address the identified unsafe condition. The 
DGAC classified these service bulletins as mandatory and issued French 
airworthiness directive 97-085-099(B), dated March 12, 1997, 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 
Sec. 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 bulletins described previously.

Cost Impact

    The FAA estimates that 118 airplanes of U.S. registry would be 
affected by this proposed AD. It would take approximately 1 work hour 
per airplane to accomplish the proposed actions, at an average labor 
rate of $60 per work hour. Required parts would be supplied by the 
manufacturer at no cost to operators. Based on these figures, the cost 
impact of the proposed AD on U.S. operators is estimated to be $7,080, 
or $60 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.

[[Page 16711]]

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-67-AD.

    Applicability: Model A320 series airplanes, as listed in Airbus 
Service Bulletin A320-27-1096, Revision 01, dated January 14, 1998; 
and Model A321 series airplanes, as listed in Airbus Service 
Bulletin A320-27-1103, dated June 14, 1996; certificated in any 
category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
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 failure of the slat and flap control computer (SFCC), 
which could result in uncommanded slat retraction during takeoff and 
consequent insufficient wing lift available to complete a successful 
takeoff, accomplish the following:
    (a) Within 24 months after the effective date of this AD, modify 
the SFCC 1 and SFCC 2 in the aft electronics rack, in accordance 
with Airbus Service Bulletin A320-27-1096, dated March 14, 1996, or 
Revision 01, dated January 14, 1998 (for Model A320 series 
airplanes); or Airbus Service Bulletin A320-27-1103, dated June 14, 
1996 (for Model A321 series airplanes); as applicable.

    Note 2: After accomplishment of the modification required by 
paragraph (a) of this AD, Temporary Revision No. 4.02.00/02 may be 
removed from the Airbus Model A320 and A321 Airplane Flight Manuals.
    (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.

    (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 97-085-099(B), dated March 12, 1997.

    Issued in Renton, Washington, on March 31, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-8904 Filed 4-3-98; 8:45 am]
BILLING CODE 4910-13-U