[Federal Register Volume 66, Number 41 (Thursday, March 1, 2001)]
[Proposed Rules]
[Pages 12913-12915]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-4934]


 ========================================================================
 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.
 
 ========================================================================
 

  Federal Register / Vol. 66, No. 41 / Thursday, March 1, 2001 / 
Proposed Rules  

[[Page 12913]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-342-AD]
RIN 2120-AA64


Airworthiness Directives; Airbus Model A319, 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 supersedure of an existing 
airworthiness directive (AD), applicable to all Model A320 series 
airplanes, that currently requires repetitive measurements of the 
deflection of the elevator trailing edge; inspections of the elevator 
servo controls and their attachments; and replacement of worn or 
damaged parts, if necessary. This action would require periodic 
inspection of the elevators for excessive freeplay; repair or 
replacement of worn parts, if excessive freeplay is detected; 
replacement of the elevator servo controls with modified elevator servo 
controls; and modification of the elevator neutral setting. It would 
also revise the applicability to include additional models of 
airplanes. This proposal is prompted by additional reports of severe 
vibration in the aft cabin of Model A320 series airplanes and studies 
which indicate that the primary cause is excessive freeplay in the 
elevator attachments. The actions specified by the proposed AD are 
intended to prevent excessive vibration of the elevators, which could 
result in reduced structural integrity, leading to reduced 
controllability of the airplane.

DATES: Comments must be received by April 2, 2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2000-NM-342-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. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2000-NM-342-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.
    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: Tim Dulin, Aerospace Engineer, ANM-
116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056; telephone (425) 227-2141; 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 action may be changed in 
light of the comments received.
    Submit comments using the following format:
     Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
     For each issue, state what specific change to the proposed 
AD is being requested.
     Include justification (e.g., reasons or data) for each 
request.
    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 action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2000-NM-342-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. 2000-NM-342-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On January 29, 1992, the FAA issued AD 92-04-06, amendment 39-8177, 
(57 FR 6068, February 20, 1992), applicable to all Airbus Model A320 
series airplanes. [A correction to that final rule was published in the 
Federal Register on April 1, 1992 (57 FR 11137).] That AD requires 
repetitive measurements of the deflection of the elevator trailing 
edge; inspections of the elevator servo controls and their attachments; 
and replacement of worn or damaged parts, if necessary. The AD was 
prompted by reports of in-flight airframe vibrations resulting from 
worn bolts and bushings on the elevator servo attachments. The 
requirements of that AD are intended to prevent excessive freeplay 
(backlash) at the elevator trailing edge, resulting in in-flight 
airframe vibrations, which could lead to reduced controllability of the 
airplane.

Actions Since Issuance of Previous Rule

    Since issuance of AD 92-04-06, there have been more reports of 
airframe vibration. To investigate this problem, Airbus conducted 
extensive flight tests with varying degrees of elevator servo control 
backlash (freeplay) and elevator hinge moments to determine the source 
of the elevator vibration. Airbus found that a combination of elevator 
freeplay and low hinge moment caused the

[[Page 12914]]

vibration. Airbus describes this vibration as limit cycle oscillation 
(i.e., sustained vibration at a fixed frequency and limited amplitude).

Explanation of Relevant Service Information

    To address this problem, Airbus issued two service bulletins and 
made a change to the Aircraft Maintenance Manual for the affected 
airplanes.
    Airbus has issued Service Bulletin A320-27-1111, dated August 16, 
1996, and Revision 01, dated November 14, 2000, which provides 
procedures to replace the existing elevator servo controls with 
modified elevator servo controls having improved spherical bearings. 
The service bulletin addresses the problem of elevator freeplay 
(backlash) at the servo control eye-end, which had been found to be due 
to wear of the spherical bearings.
    Airbus has also issued Service Bulletin A320-27-1114, Revision 04, 
dated December 7, 1999, which provides procedures to modify the 
elevator neutral setting to ensure that the elevators are sufficiently 
loaded in most flight conditions. The Direction Generale de l'Aviation 
Civile (DGAC), which is the airworthiness authority for France, has 
approved these service bulletins, but has not classified them as 
mandatory.
    Finally, Airbus has changed the Aircraft Maintenance Manual (AMM) 
to reduce the allowable elevator freeplay from 10 millimeters to 7 
millimeters.

FAA's Conclusions

    Airbus describes the vibration as a limit cycle oscillation 
(resulting from a nonlinear behavior of the structure) that is 
acceptable from a static strength, fatigue, and controllability 
standpoint. Nevertheless, the FAA considers the vibration to be an 
aeroelastic stability problem, which could potentially result in 
reduced structural integrity, leading to reduced controllability of the 
airplane. In order to ensure that this condition does not occur in-
service, the FAA proposes to mandate repetitive inspections for 
freeplay per the new aircraft maintenance manual limits, modification 
of the actuator bearings, and incorporation of the new neutral setting 
of the elevator control surface.

U.S. Type Certification of the Airplanes

    These airplane models are manufactured in France and are type 
certificated for operation in the United States under the provisions of 
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and 
the applicable bilateral airworthiness agreement. Pursuant to this 
bilateral 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 supersede AD 92-04-06 to 
require periodic inspection of the elevators for excessive freeplay; 
repair or replacement of worn parts, if excessive freeplay is detected; 
replacement of the elevator servo controls with modified elevator servo 
controls; and modification of the elevator neutral setting. These 
actions would be required to be accomplished in accordance with the 
service bulletins and AMM described above. The proposed AD would also 
revise the applicability to add Model A319 and A321 series airplanes, 
which are similar in design to Model A320 series airplanes, but were 
not on the U.S. registry at the time of issuance of AD 92-04-06.

Cost Impact

    There are approximately 291 airplanes of U.S. registry that would 
be affected by this proposed AD.
    Inspection for freeplay in the elevators would take approximately 2 
work hours at an average labor rate of $60 per work hour. There would 
be no charge for required parts. Based on these figures, the cost 
impact of the initial inspection proposed by this AD on U.S. operators 
is estimated to be $34,920, or $120 per airplane.
    Replacement of the elevator servo controls would take approximately 
7 work hours at an average labor rate of $60 per work hour. There would 
be no charge for required parts. Based on these figures, the cost 
impact of the replacement of the elevator servo controls proposed by 
this AD on U.S. operators is estimated to be $122,220, or $420 per 
airplane.
    Change of the elevator neutral setting would take approximately 12 
work hours at an average labor rate of $60 per work hour. There would 
be no charge for required parts. Based on these figures, the cost 
impact of the replacement of the change of the elevator neutral setting 
proposed by this AD on U.S. operators is estimated to be $209,520, or 
$720 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the current or proposed 
requirements of this AD action, and that no operator would accomplish 
those actions in the future if this AD were not adopted. The cost 
impact figures discussed in AD rulemaking actions represent only the 
time necessary to perform the specific actions actually required by the 
AD. These figures typically do not include incidental costs, such as 
the time required to gain access and close up, planning time, or time 
necessitated by other administrative actions.

Regulatory Impact

    The regulations proposed herein would not have a substantial direct 
effect 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, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    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 removing amendment 39-8177 (57 FR

[[Page 12915]]

6068, February 20, 1992), and by adding a new airworthiness directive 
(AD), to read as follows:

Airbus Industrie: Docket 2000-NM-342-AD. Supersedes AD 92-04-06, 
Amendment 39-8177.

    Applicability: All Model A319, A320, and A321 series airplanes; 
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 (e) 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 excessive vibration of the elevators, which could 
result in reduced structural integrity, leading to reduced 
controllability of the airplane, accomplish the following:

Inspection

    (a) Within 18 months from the last inspection for excessive 
freeplay or within 3 months after the effective date of this AD, 
whichever occurs later: Inspect the elevators for excessive 
freeplay, using a load application tool and a spring scale assembly, 
in accordance with Airbus A319/A320 Aircraft Maintenance Manual 
(AMM) Task 27-34-00-200-001, including all changes through August 1, 
2000. Thereafter, repeat the inspection at intervals not to exceed 
18 months.

Repair

    (b) If any inspection required by paragraph (a) of this AD 
indicates that the freeplay in the elevator exceeds 7 millimeters: 
Prior to further flight, repair the elevator or servo controls, in 
accordance with Airbus A319/A320 AMM Task 27-34-51-200-001 and/or 
27-34-41-200-001, as applicable, including all changes through 
August 1, 2000.

Replacement

    (c) For the airplanes listed in Airbus Service Bulletin A320-27-
1111, Revision 01, dated November 14, 2000: Within 18 months after 
the effective date of this AD, replace the elevator servo controls 
with modified elevator servo controls, in accordance with Airbus 
Service Bulletin A320-27-1111, dated August 16, 1996; or Revision 
01, dated November 14, 2000.
    (d) For the airplanes listed in Airbus Service Bulletin A320-27-
1114, Revision 04, dated December 7, 1999: Within 18 months after 
the effective date of this AD, shift the elevator neutral setting to 
minus 0.5 degrees, nose-up, in accordance with Airbus Service 
Bulletin A320-27-1114, Revision 04, dated December 7, 1999.

Alternative Methods of Compliance

    (e) 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, 
Transport Airplane Directorate, FAA. 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, ANM-116.

Special Flight Permits

    (f) 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.

    Issued in Renton, Washington, on February 22, 2001.
Donald L. Riggin,
Acting Manager,, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-4934 Filed 2-28-01; 8:45 am]
BILLING CODE 4910-13-U