Airworthiness Directives; Airbus Model A320 Series Airplanes

[Federal Register Volume 62, Number 39 (Thursday, February 27, 1997)]
[Rules and Regulations]
[Pages 8872-8873]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-4715]



[[Page 8872]]

=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-NM-11-AD; Amendment 39-9948; AD 97-05-04]
RIN 2120-AA64


Airworthiness Directives; Airbus Model A320 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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

SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to certain Airbus Model A320-111, -211, and -231 
series airplanes, that currently requires replacing the existing 
standby generator control unit (GCU) with a new improved standby GCU. 
That action was prompted by reports of improper functioning of the 
standby GCU. This amendment requires replacement of the GCU on addition 
affected airplanes. For some airplanes, it also will require that a 
wiring modification be accomplished prior to replacement of the GCU. 
The actions specified by this AD are intended to prevent such improper 
functioning of the GCU, which could result in the loss of the standby 
emergency generation system.

DATES: Effective April 3, 1997.
    The incorporation by reference of certain publications, as listed 
in the regulations, is approved by the Director of the Federal Register 
as of April 3, 1997.

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: Tim Backman, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 
227-2797; fax (206) 227-1149.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 91-01-01, 
amendment 39-6845 (55 FR 51895, December 18, 1990), which is applicable 
to certain Airbus Model A320-111, -211, and -231 series airplanes, was 
published in the Federal Register on October 23, 1996 (61 FR 54963). 
The action proposed to supersede AD 91-01-01 to continue to require 
replacement of the existing standby GCU with an improved standby GCU. 
The action also proposed to require the identical replacement to be 
accomplished on additional airplanes. In addition, for some airplanes, 
the action proposed that a wiring modification be accomplished prior to 
replacement of the GCU.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the two comments received.

Support for the Proposal

    Both commenters support the proposed AD.

Conclusion

    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 as proposed.

Cost Impact

    There are approximately 106 Airbus Model A320 series airplanes of 
U.S. registry that will be affected by this AD. Of this number, 18 were 
previously subject to the requirements of AD 91-01-01, and the 
remaining 88 are the airplanes that have been added to the AD 
applicability by this action.
    The replacement of the GCU that is required by this AD takes 
approximately 1.5 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Required parts will cost approximately 
$450 per airplane. Based on these figures, the cost impact of this 
required action on U.S. operators is estimated to be $57,240 for the 
entire affected fleet (or $540 per airplane). However, based on the 
effective date and the compliance time established by AD 91-01-01, the 
FAA assumes that the 18 airplanes that were previously subject to that 
AD already have completed the required replacement of the GCU. 
Therefore, the future cost impact of the replacement action is only 
$47,520 (for the 88 airplanes that have been added to the applicability 
of the AD).
    For airplanes on which the modification of the wiring assembly is 
required, it will take approximately 8.5 work hours to accomplish, at 
an average labor rate of $60 per work hour. Based on these figures, the 
cost impact of this action on U.S. operators of those airplanes is 
estimated to be $510 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the new 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 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. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing amendment 39-6845 (55 FR 
51895, December 18, 1990), and by adding a new airworthiness directive

[[Page 8873]]

(AD), amendment 39-9948, to read as follows:

97-05-04 Airbus Industrie: Amendment 39-9948. Docket 96-NM-11-AD. 
Supersedes AD 91-01-01, Amendment 39-6845.

    Applicability: Model A320 series airplanes; on which a generator 
control unit (GCU) having part number (P/N) 520915 has not been 
installed, or on which Airbus Modification 21052 (reference Airbus 
Service Bulletin A320-24-1022) and Airbus Modification 21736 
(reference Airbus Service Bulletin A320-24-1035) have 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 
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 (c) 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 loss of the standby emergency generation system, 
which provides necessary back-up capability when both main 
generators fail, accomplish the following:

    Note 2: Airbus Service Bulletin A320-24-1035 and Airbus Service 
Bulletin A320-24-1022 refer to Vickers Service Bulletin No. 520754-
24-01 as an additional source of specific procedural information.

    (a) For Model A320-111, -211, and -231 series airplanes; having 
serial numbers 003 through 058, inclusive, 060 through 067, 
inclusive, 069 through 072, inclusive, 074 through 083, inclusive, 
and 085: Within 150 days after January 28, 1991 (the effective date 
of AD 91-01-01, amendment 39-6845), remove one generator control 
unit (GCU) identified as 1XE part number (P/N) 520754, and install a 
modified GCU identified as 1XE, P/N 520915, in accordance with 
Airbus Service Bulletin A320-24-1035, Revision 1, dated February 27, 
1990, or Revision 2, dated June 24, 1994. Following installation, 
perform an operational test of the emergency generation system, 
emergency GCU from the centralized fault display system, and the 
static inverter, in accordance with the service bulletin.
    (b) For airplanes not subject to paragraph (a) of this AD: 
Within 150 days after the effective date of this AD, accomplish 
either paragraph (b)(1) or (b)(2) of this AD, as applicable.

    Note 3: Replacement of the GCU accomplished prior to the 
effective date of this AD in accordance with Airbus Service Bulletin 
A320-24-1035, Revision 1, dated February 27, 1990, is considered 
acceptable for compliance with the actions specified in this 
paragraph.

    (1) For airplanes equipped with GCU 1XE having P/N 520754: 
Replace the GCU 1XE, having P/N 520754, in zone 125 of the avionics 
compartment, with a modified GCU 1XE, having P/N 520915, in 
accordance with Airbus Service Bulletin A320-24-1035, Revision 2, 
dated June 24, 1994. Prior to further flight following 
accomplishment of the replacement, perform an operational test of 
the affected components in accordance with that service bulletin.
    (2) For airplanes equipped with GCU 1XE having P/N 520738: 
Accomplish the requirements of paragraphs (b)(2)(i) and (b)(2)(ii) 
of this AD:
    (i) Modify the wiring in relay box 103VU, the wiring in power 
center AC/DC emergency 106VU, and the wiring between 103VU and 
106VU, in accordance with Airbus Service Bulletin A320-24-1022, 
Revision 1, dated February 27, 1990.

    Note 4: Modification accomplished prior to the effective date of 
this AD in accordance with Airbus Service Bulletin A320-24-1022, 
dated June 16, 1989, is considered acceptable for compliance with 
this paragraph.

    (ii) After modifying the wiring, replace the GCU 1XE, having P/N 
520738, located in the nose gear well in zone 125, with a modified 
GCU 1XE, having P/N 520915, in accordance with Airbus Service 
Bulletin A320-24-1035, Revision 2, dated June 24, 1994. Prior to 
further flight following accomplishment of the replacement, perform 
an operational test of the affected components in accordance with 
that service bulletin.
    (c) 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, 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 5: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    (d) 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.
    (e) The actions shall be done in accordance with the following 
Airbus Service Bulletins, which contain the specified lists 
effective pages:

--------------------------------------------------------------------------------------------------------------------------------------------------------
  Service bulletin number and date                       Page No.                       Revision level shown on page           Date shown on page       
--------------------------------------------------------------------------------------------------------------------------------------------------------
A320-24-1035, Revision 1, February   1, 2...........................................  1...............................  February 27, 1990.              
 27, 1990.                           3, 4...........................................  Original........................  October 20, 1989.               
A320-24-1035, Revision 2, June 24,   1-4............................................  2...............................  June 24, 1994.                  
 1994.                                                                                                                                                  
A320-24-1022, Revision 1, February   1, 5, 6, 13, 14, 19-21.........................  1...............................  February 27, 1990.              
 27, 1990.                           2-4, 7-12, 15-18, 22...........................  Original........................  June 16, 1989.                  
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The incorporation by reference of the service documents listed 
above is 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.
    (f) This amendment becomes effective on April 3, 1997.

    Issued in Renton, Washington, on February 20, 1997.
James V. Devany,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-4715 Filed 2-26-97; 8:45 am]
BILLING CODE 4910-13-U

The complete text was extracted from the official GovInfo HTML edition for this publication. Acquired 2026-10-09T05:12:57.089987+00:00. Text extraction preserves the recorded source wording; it does not determine current requirements.

Open the captured official edition

Source SHA-256

6ba62cfecc3da9fa499aac5fdf80720c642359a7760cfe684ef989e9f77dd0c2

Text SHA-256

38959b6990ebfcae6450a991516b67d9a152fde2493db22a901a99c7d680b6f3