[Federal Register Volume 63, Number 82 (Wednesday, April 29, 1998)]
[Rules and Regulations]
[Pages 23374-23376]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-11075]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-NM-143-AD; Amendment 39-10499; AD 98-09-18]
RIN 2120-AA64


Airworthiness Directives; Airbus Industrie Model A320 and A321 
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 Industrie Model A320 and A321 series 
airplanes, that requires replacement of two elevator aileron computers 
(ELAC) with ELAC's that contain new software. This amendment is 
prompted by a report indicating difficulty maintaining the intended 
flight path during landing in turbulent conditions. The actions 
specified by this AD are intended to prevent situations that could lead 
to reduced controllability of the airplane due to adverse airplane-
pilot coupling characteristics.

DATES: Effective June 3, 1998.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of June 3, 1998.

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: 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: 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 Industrie Model 
A320 and A321 series airplanes was published in the Federal Register on 
January 7, 1997 (62 FR 949). That action proposed to require 
replacement of two elevator aileron computers (ELAC) with ELAC's that 
contain new software.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    Two commenters support the proposed rule.
    One commenter, Airbus, does not object to the proposed AD, but 
offers the following comments suggesting changes for clarity and 
accuracy. The commenter requests that the statement of unsafe 
condition, ``To prevent reduced controllability of the airplane due to 
problems associated with the ELAC, accomplish the following: * * *,'' 
be replaced with, ``In order to adapt lateral control law to real flap 
position in case of failure/jamming of flaps, and in order to harmonize 
the lateral behavior between `full' and `3' configurations, in 
turbulence, of the ELAC, accomplish the following: * * *.'' The 
commenter states that its proposed wording of the unsafe condition is 
supported by the fact that the improvement of the ELAC is the result of 
an in-service event that arose from three conditions surrounding that 
event:

--Very strong turbulence during landing preparation;
--Flaps locked between ``full'' and ``3'' configurations resulting from 
flaps extension under strong turbulent conditions, the monitoring of 
the interconnecting strut between inner and outer flap having detected 
an abnormal surfaces displacement; and
--An electronic centralized aircraft monitor (ECAM) procedure 
requesting to select slat/flap lever to ``conf 3'' when flaps are 
locked between configurations ``3'' and ``full'' (lever in position 
``full'').

Additionally, the commenter notes that no system failure initiated the 
reported event. In conjunction with its

[[Page 23375]]

request, the commenter also questions the accuracy of a number of 
statements made in the notice of proposed rulemaking (NPRM), such as 
whether the uncommanded roll angle experienced was actually as great as 
30 degrees.
    The FAA concurs partially. The FAA agrees that the statement of 
unsafe condition should be revised. However, the FAA does not agree 
with the commenter's suggested wording of the unsafe condition. The FAA 
notes that the preamble of the proposed rule indicates that the unsafe 
condition is due to uncommanded movements of the ailerons. The FAA 
finds that a more accurate statement of the unsafe condition would 
include the fact that it is actually associated with pilot response 
coupled with the handling characteristics of the airplane. In light of 
this, the FAA has revised the statement of unsafe condition throughout 
this final rule to state that the actions specified by this AD are 
intended to prevent situations that could lead to reduced 
controllability of the airplane due to adverse airplane-pilot coupling 
characteristics.
    The commenter also notes that the proposed AD refers to part number 
C12370AAA01 in error. The FAA has revised the final rule to specify the 
correct part number: C12370AA01.
    The commenter indicates that the referenced service bulletin has 
been revised from the original issue to Revision 1. The FAA 
acknowledges that Airbus has issued Service Bulletin A320-27-1082, 
Revision 1, dated September 6, 1995, since the issuance of the proposed 
rule. This service bulletin revision contains essentially the same 
information as that specified in the original issue of the service 
bulletin; however, the ELAC Configuration Chart (Figure 1) and the 
effectivity listing of the service bulletin has been revised in 
Revision 1 to reduce the number of affected airplanes. In light of 
this, the applicability of the final rule has been revised to reference 
Revision 1 of the service bulletin. In addition, since compliance with 
either the original issue or Revision 1 of the service bulletin is 
acceptable, the final rule has been revised to cite Revision 1 of the 
service bulletin as an additional source of service information.
    One commenter states that the cost impact information included in 
the proposed AD specifies that 108 Model A320 and A321 series airplanes 
would be affected. The commenter notes that no Model A321 series 
airplanes are currently on the U.S. Register. The FAA acknowledges this 
remark; however, the cost of compliance is the same regardless of 
whether all 108 airplanes are A320's or some A321's are included. The 
AD applies to Model A321 series airplanes, as well as Model A320 series 
airplanes, to ensure compliance in the event one or more affected Model 
A321 series airplanes is imported after the effective date of this 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 with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    The FAA estimates that 108 Model A320 and A321 series airplanes of 
U.S. registry will be affected by this AD, that it will take 
approximately 3 work hours per airplane to accomplish the required 
actions, and that the average labor rate is $60 per work hour. Required 
parts will be provided by the manufacturer at no cost to operators. 
Based on these figures, the cost impact of the AD on U.S. operators is 
estimated to be $19,440, or $180 per airplane.
    The 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.

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 adding the following new 
airworthiness directive:

98-09-18  Airbus: Amendment 39-10499. Docket 95-NM-143-AD.

    Applicability: Model A320 and A321 series airplanes; as listed 
in Airbus Service Bulletin A320-27-1082, Revision 1, dated September 
6, 1995; 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 situations that could lead to reduced controllability 
of the airplane due to adverse airplane-pilot coupling 
characteristics, accomplish the following:
    (a) Within 1 year after the effective date of this AD, replace 
the ELAC's having part numbers (P/N) 3945122307 and/or P/N 
C12370AA01 and located in aft electronics rack 80VU, with modified 
ELAC's having P/N 3945122502, in accordance with Airbus Service 
Bulletin A320-27-1082, dated April 25, 1995, or Revision 1, dated 
September 6, 1995.

    Note 2: Airbus Service Bulletin A320-27-1082 references Sextant 
Service Bulletins 394512-27-014, dated August 11, 1995 (for 
airplanes on which Airbus Modification 24136P3436 has not been 
installed); and C12370A-27-001, dated May 2, 1995 (for airplanes on 
which Airbus Modification

[[Page 23376]]

24136P3436 has been installed); as additional sources of procedural 
service information for modification of the ELAC's.

    (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 
Secs. 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 actions shall be done in accordance with Airbus Service 
Bulletin A320-27-1082, dated April 25, 1995, or Airbus Service 
Bulletin A320-27-1082, Revision 1, dated September 6, 1995. Revision 
1 contains the specified effective pages:

------------------------------------------------------------------------
                                  Revision                              
           Page no.             level shown       Date shown on page    
                                  on page                               
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1-2, 4-10, 12-14.............  1............  September 6, 1995.        
3, 11, 15....................  Original.....  April 25, 1995.           
------------------------------------------------------------------------

    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.

    Note 4: The subject of this AD is addressed in French 
airworthiness directive (C/N) 95-203-072(B), dated October 11, 1995, 
as corrected by Erratum dated November 8, 1995.

    (e) This amendment becomes effective on June 3, 1998.

    Issued in Renton, Washington, on April 21, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-11075 Filed 4-28-98; 8:45 am]
BILLING CODE 4910-13-U