[Federal Register Volume 63, Number 29 (Thursday, February 12, 1998)]
[Proposed Rules]
[Pages 7076-7078]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-3515]


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 Proposed Rules
                                                 Federal Register
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
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 

  Federal Register / Vol. 63, No. 29 / Thursday, February 12, 1998 / 
Proposed Rules  

[[Page 7076]]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-NM-194-AD]
RIN 2120-AA64


Airworthiness Directives; Airbus Model A310 and A300-600 Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Supplemental notice of proposed rulemaking; reopening of 
comment period.

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SUMMARY: This document revises an earlier proposed airworthiness 
directive (AD), applicable to certain Airbus Model A310 and A300-600 
series airplanes, that would have required modifying the rudder trim 
switch and control knob. That proposal was prompted by reports of in-
flight uncommanded rudder trim activation due to inadvertent activation 
of the rudder trim switch, failure of the switch, or incorrect 
installation of the switch. This new action revises the proposed rule 
by requiring replacement of the rudder trim switch in the flight 
compartment with a new switch having a longer shaft; modification of 
wiring in panel 408VU; and replacement of the control knob with a new 
knob, as necessary. This actions specified by this new proposed AD are 
intended to prevent inadvertent and uncommanded rudder trim activation, 
which could result in yaw and roll excursions and consequent reduced 
controllability of the airplane.

DATES: Comments must be received by March 9, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 96-NM-194-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 the 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 96-NM-194-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. 96-NM-194-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    A proposal to amend part 39 of the Federal Aviation Regulations (14 
CFR part 39) to add an airworthiness directive (AD), applicable to 
certain Airbus Model A310 and A300-600 series airplanes, was published 
as a notice of proposed rulemaking (NPRM) in the Federal Register on 
April 1, 1997 (62 FR 15431). That NPRM would have required modifying 
the rudder trim switch and control knob. That proposal was prompted by 
reports of in-flight uncommanded rudder trim activation due to 
inadvertent activation of the rudder trim switch, failure of the 
switch, or incorrect installation of the switch. Such activation, if 
not corrected, could result in uncommanded yaw/roll excursions and 
consequent reduced controllability of the airplane.

Actions Since Issuance of Previous Proposal

    Since the issuance of the originally proposed NPRM, the Direction 
Generale de l'Aviation Civile (DGAC), which is the airworthiness 
authority for France, notified the FAA that the unsafe condition 
addressed in the NPRM may continue to exist on certain Airbus Model 
A310 and A300-600 series airplanes that were modified previously in 
accordance with two of the service bulletins cited in that NPRM:
    1. Airbus Service Bulletin A300-27-6027, Revision 2, dated August 
22, 1995, or Revision 3, dated March 13, 1996 (for Model A300-600 
series airplanes); and
    2. Airbus Service Bulletin A310-27-2071, Revision 2, dated August 
22, 1995, or Revision 3, dated March 13, 1996 (for Model A310 series 
airplanes).
    The DGAC advises the FAA of two reports indicating that a rudder 
trim switch that was replaced in accordance with these service 
bulletins did not return to a centered (neutral) position after 
release. Because the replacement and modification procedures in these 
service bulletins do not adequately prevent inadvertent and uncommanded 
rudder trim activation, the DGAC has issued a new French airworthiness 
directive, 97-111-219(B), dated May 7, 1997, to correct the unsafe 
condition.
    Airbus has issued two new and two revised service bulletins, as 
described below. The FAA has determined that

[[Page 7077]]

accomplishment of the actions specified in these service bulletins will 
ensure the appropriate clearance between the rudder trim control knob 
and panel 408VU, which will correct the identified unsafe condition.
    1. Two new Airbus Service Bulletins, A300-27-6037 and A310-27-2084, 
both dated February 12, 1997, describe procedures for replacement of 
the existing rudder trim switch with a switch having a new part number, 
and modification of the wiring in panel 408VU. The new switch, which 
has a longer shaft, was designed to prevent interference with the panel 
by ensuring the appropriate clearance between the control knob and the 
panel.
    2. Revisions to Airbus Service Bulletins A300-27-6022, Revision 3 
(for Model A300-600 series airplanes), and A310-27-2058, Revision 3 
(for Model A310 series airplanes), both dated September 26, 1996, 
describe procedures for replacement of the rudder trim control knob in 
panel 408VU, and an inspection to ensure the appropriate clearance 
between the rudder trim control knob and panel 408VU. The configuration 
of the knob was changed in Revision 2 of these service bulletins and 
was proposed in the NPRM.
    Accomplishment of the actions specified in the service bulletins is 
intended to adequately address the identified unsafe condition.
    The DGAC classified the Airbus service bulletins as mandatory, and 
issued French airworthiness directives 95-246-193(B), dated December 6, 
1995, and 97-111-219(B), dated May 7, 1997, in order to assure the 
continued airworthiness of these airplanes in France.

FAA's Conclusions

    The FAA concludes that the new design change to the rudder trim 
switch and the previous design change to the control knob specified in 
the service bulletins described previously will reduce the possibility 
of inadvertent and uncommanded activation of the rudder.
    The FAA has determined that, in order to adequately address the 
identified unsafe condition (inadvertent and uncommanded rudder trim 
activation), the originally proposed rule must be revised to require 
the actions specified in the service bulletins described previously, 
except as described below.

Differences Between Service Bulletins and the Supplemental NPRM

    Although Revision 3 of Airbus Service Bulletins A310-27-2058 and 
A300-27-6022 provides inspection procedures for setting the appropriate 
clearance between panel 408VU and the rudder trim control knob, this 
supplemental NPRM does not require such an inspection. The FAA has 
determined that installation of the new switch will ensure the 
appropriate clearance between the control knob and panel when the new 
switch is installed, and that this design change precludes the 
necessity for an inspection.

Conclusion

    Because these changes expand the scope of the originally proposed 
rule, the FAA has determined that it is necessary to reopen the comment 
period to provide additional opportunity for public comment.

Cost Impact

    The FAA estimates that 90 Airbus Model A310 and A300-600 series 
airplanes of U.S. registry would be affected by this proposed AD.
     Replacement of the rudder trim switch and modification of 
the wiring would take approximately 7 hours per airplane to accomplish, 
at an average labor rate of $60 per work hour. Required parts would be 
provided by the manufacturer at no cost to the operators. Based on 
these figures, the cost impact on U.S. operators is estimated to be 
$37,800, or $420 per airplane.
     Replacement of the rudder trim control knob would take 
approximately 1 hour per airplane to accomplish, at an average labor 
rate of $60 per work hour. Required parts would cost approximately $296 
per airplane. Based on these figures, the cost impact on U.S. operators 
is estimated to be $32,040, or $356 per airplane.
    The cost impact figures discussed above are 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 to 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 96-NM-194-AD.

    Applicability: Model A310 and A300-600 series airplanes on which 
Airbus Modifications 8566 and 11662 have not been incorporated, 
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 (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 inadvertent and uncommanded rudder trim activation, 
which could result in yaw and roll excursions and consequent reduced 
controllability of the airplane, accomplish the following:
    (a) Within 90 days after the effective date of this AD, 
accomplish the actions required by paragraphs (a)(1) and (a)(2) of 
this AD.

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    (1) Replace rudder trim switch, part number (P/N) 097-023-00, in 
the flight compartment with a new switch, P/N 097-023-01; and modify 
the wiring in panel 408VU; in accordance with Airbus Service 
Bulletin A310-27-2084 (for Model A310 series airplanes), and Airbus 
Service Bulletin A300-27-6037 (for Model A300-600 series airplanes), 
both dated February 12, 1997.
    (2) Replace the rudder trim control knob on the rudder trim 
switch with a new knob in accordance with Airbus Service Bulletin 
A310-27-2058, Revision 3, dated September 26, 1996, or Revision 2, 
dated August 28, 1995 (for Model A310 series airplanes); and Airbus 
Service Bulletin A300-27-6022, Revision 3, dated September 26, 1996, 
or Revision 2, dated August 28, 1995 (for Model A300-600 series 
airplanes).
    (b) As of the effective date of this AD, no person shall install 
in the flight compartment of any airplane a rudder trim switch 
having P/N 097-023-00.
    (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, 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 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the International Branch.

    (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.

    Note 3: The subject of this AD is addressed in French 
airworthiness directives 95-246-193(B), dated December 6, 1995, and 
97-111-219(B), dated May 7, 1997.

    Issued in Renton, Washington, on February 5, 1998.
Darrell M. Pederson,


Acting Manager, Transport Airplane Directorate, Aircraft 
Certification Service.

[FR Doc. 98-3515 Filed 2-11-98; 8:45 am]
BILLING CODE 4910-13-M