[Federal Register Volume 59, Number 234 (Wednesday, December 7, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-29163]


[[Page Unknown]]

[Federal Register: December 7, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 92-NM-217-AD; Amendment 39-9080; AD 94-24-07]

 

Airworthiness Directives; Airbus Model A320 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Airbus Model A320 series airplanes, that requires 
modification of the brake steering control unit (BSCU). This amendment 
is prompted by reports that the BSCU on these airplanes allowed a 90-
degree rotation of the nose gear after landing, which resulted in 
significant damage to the wheels. The actions specified by this AD are 
intended to prevent failure of the nose gear tires and wheels and the 
loss of directional control of the airplane while it is on the ground.

DATES: Effective on January 6, 1995.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of January 6, 1995.

ADDRESSES: The service information referenced in this AD may be 
obtained from Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707 
Blagnac Cedex, France. This information may be examined at the Federal 
Aviation Administration (FAA), Transport Airplane Directorate, Rules 
Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of 
the Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.

FOR FURTHER INFORMATION CONTACT: Stephen Slotte, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 
227-2797; fax (206) 227-1320.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain Airbus Model A320 series 
airplanes was published in the Federal Register on April 16, 1993 (58 
FR 19787). That action proposed to require modification of the brake 
steering control unit (BSCU) for certain airplanes equipped with twin 
wheel main landing gears (MLG).
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    Both commenters support the proposed rule.
    Since the issuance of the proposed rule, Airbus issued Service 
Bulletin A320-32-1100, Revision 1, dated November 9, 1993, which 
describes procedures for modification of the BSCU on certain Model A320 
series airplanes equipped with bogie MLG's. The modification involves 
upgrading the currently installed standard 3 BSCU functional software 
to a new standard 3.1 BSCU, which includes reprogramming of certain 
software for each system of the BSCU. Accomplishment of the 
modification will allow activation of the nose wheel steering at main 
gear touchdown, and authorization of rudder pedal action that would 
allow progressive amplitude authority from 130 to 40 knots. The 
Direction Generale de l'Aviation Civile (DGAC), which is the 
airworthiness authority for France, classified this service bulletin as 
mandatory and issued French Airworthiness Directive 92-117-025(B)R1, 
dated August 18, 1993, in order to assure the continued airworthiness 
of these airplanes in France.
    The FAA finds that Model A320 series airplanes equipped with bogie 
MLG's are subject to the same unsafe condition that is addressed by 
this rule. In light of this, the FAA has revised the applicability of 
the final rule to include these airplanes. However, there currently are 
no Model A320 series airplanes equipped with bogie MLG's on the U.S. 
Register; therefore, no additional U.S. airplanes are affected directly 
by this AD action. The FAA considers that the revision to the 
applicability of the rule is necessary in order to ensure that the 
unsafe condition is addressed in the event that these specific 
airplanes are imported and placed on the U.S. Register in the future.
    In addition, the FAA has revised paragraph (a) of the final rule to 
cite the appropriate service information for modification of the BSCU 
on airplanes equipped with bogie MLG's.
    Since the issuance of the proposed rule, Airbus also has issued 
Service Bulletin A320-32-1094, Revision 3, dated June 24, 1993. 
Revision 3 of the service bulletin is essentially identical to Revision 
2 (which was cited in the proposal as the appropriate source of service 
information), but revises the effectivity listing to include one 
additional airplane. The FAA has determined that this additional 
airplane is operated currently by a non-U.S. operator under foreign 
registry; therefore, this airplane is not affected directly by this AD 
action. The FAA has revised paragraph (a) of the final rule to cite 
Revision 3 of the service bulletin as an additional source of service 
information for accomplishment of the required modification.
    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any U.S. operator nor increase the 
scope of the AD.
    The FAA estimates that 52 airplanes of U.S. registry will be 
affected by this AD, that it will take approximately 1 work hour per 
airplane to accomplish the required actions, and that the average labor 
rate is $55 per work hour. Required parts will be supplied by the 
vendor at no cost to operators. Based on these figures, the total cost 
impact of the AD on U.S. operators is estimated to be $2,860, or $55 
per airplane.
    The total cost impact figure discussed above is based on 
assumptions that no operator has yet accomplished any of the 
requirements of this AD action, and that no operator would accomplish 
those actions in the future if this AD were not adopted.
    The regulations adopted herein will 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 final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under 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. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

94-24-07  Airbus Industrie: Amendment 39-9080. Docket 92-NM-217-AD.

    Applicability: Model A320 series airplanes equipped with twin 
wheel main landing gears (MLG) on which Airbus Industrie Service 
Bulletin A320-32-1094 or Airbus Industrie Modification 22990 has not 
been accomplished; and Model A320 series airplanes equipped with 
bogie MLG's on which Airbus Industrie Service Bulletin A320-32-1100 
or Airbus Industrie Modification 23106 has not been accomplished; 
certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent failure of the nose gear tires and wheels and the 
loss of directional control, accomplish the following:
    (a) Within 6 months after the effective date of this AD, modify 
the brake steering control unit (BSCU) in accordance with Airbus 
Industrie Service Bulletin A320-32-1094, Revision 2, dated November 
25, 1992; or Revision 3, dated June 24, 1993 (for airplanes equipped 
with twin wheel MLG's); or in accordance with Airbus Industrie 
Service Bulletin A320-32-1100, Revision 1, dated November 9, 1993 
(for airplanes equipped with bogie MLG's); as applicable.
    (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, Standardization Branch, ANM-113, 
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, 
Standardization Branch, ANM-113.

    Note: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    (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.
    (d) The modification shall be done in accordance with the 
following Airbus Industrie service bulletins, as applicable, which 
contain the following list of effective pages:

----------------------------------------------------------------------------------------------------------------
                                                                           Revision level                       
           Service bulletin, reference and date               Page no.      shown on page   - Date shown on page
----------------------------------------------------------------------------------------------------------------
A320-32-1094, Revision 2, November 25, 1992-.............  1, 7.........  2...............  Nov. 25, 1992.      
                                                           2-6..........  1...............  May 26, 1992.       
                                                           8-11-........  Original-.......  Mar. 25, 1992.      
A320-32-1094, Revision 3, June 24, 1993-.................  1, 3, 6......  3...............  June 24, 1993.      
                                                           2, 4, 5......  1...............  May 26, 1992.       
                                                           7............  2...............  Nov. 25, 1992.      
                                                           8-11.........  Original-.......  Mar. 25, 1992.      
A320-32-1100, Revision 1, November 9, 1993-..............  1, 3-7.......  Original........  June 18, 1993.      
                                                           2-...........  1...............  Nov. 9, 1993.       
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This incorporation by reference was approved by the Director of the 
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 
51. Copies may be obtained from Airbus Industrie, 1 Rond Point 
Maurice Bellonte, 31707 Blagnac Cedex, France. Copies may be 
inspected at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington; or at the Office of the Federal 
Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
    (e) This amendment becomes effective on January 6, 1995.

    Issued in Renton, Washington, on November 21, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-29163 Filed 12-6-94; 8:45 am]
BILLING CODE 4910-13-U