[Federal Register Volume 63, Number 83 (Thursday, April 30, 1998)]
[Proposed Rules]
[Pages 23690-23692]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-11435]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-310-AD]
RIN 2120-AA64
Airworthiness Directives; Airbus Model A310 and A300-600 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 certain Airbus Model A310
and A300-600 series airplanes, that currently requires, among other
things, repetitive inspections to ensure correct synchronization of the
hydraulic control valves of the trimmable horizontal stabilizer (THS)
actuator; replacement of the horizontal stabilizer actuator motors with
new or serviceable motors and resynchronization of the valves, or
adjustment of the synchronization, if necessary; and a functional test
of the THS. This proposed AD would add a requirement to replace the
hydraulic motor of the THS with an improved motor, which would
constitute terminating action for the repetitive inspections. This
proposal also would expand the applicability to include additional
airplanes. This proposal is prompted by the issuance of mandatory
continuing airworthiness information by a foreign civil airworthiness
authority. The actions specified by the proposed AD are intended to
prevent desynchronization of the hydraulic control valves, which could
result in runaway of the horizontal stabilizer to its full up or down
position, subsequent reduced maneuvering capability, and potential
pitch upset.
DATES: Comments must be received by June 1, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 97-NM-310-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 this 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 97-NM-310-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. 97-NM-310-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
On January 12, 1996, the FAA issued AD 96-01-52, amendment 39-9491
(61
[[Page 23691]]
FR 2697, January 29, 1996), applicable to certain Airbus Model A310 and
A300-600 series airplanes. That AD requires, among other things,
repetitive inspections to ensure correct synchronization of the
hydraulic control valves of the trimmable horizontal stabilizer (THS)
actuator; replacement of the horizontal stabilizer actuator motors with
new or serviceable motors and resynchronization of the valves, or
adjustment of the synchronization, if necessary; and a functional test
of the THS. That action was prompted by a report of desynchronization
of the hydraulic control valves that direct fluid to the horizontal
stabilizer actuator motors, which resulted in uncommanded movement of
the THS. The actions specified by that AD are intended to prevent such
desynchronization, which could lead to runaway of the horizontal
stabilizer to its full up or down position, subsequent reduced
maneuvering capability, and potential pitch upset.
Actions Since Issuance of Previous Rule
In the preamble to AD 96-01-52, the FAA specified that the actions
required by that AD were considered ``interim action.'' The FAA
indicated that it might consider further rulemaking action once a final
action was identified. The manufacturer now has developed a
modification of the hydraulic motor of the THS that includes an
improved camplate retention device and pin. The FAA has determined that
further rulemaking action is indeed necessary in order to address the
unsafe condition and ensure the continued safe operation of the
affected airplanes; this proposed AD follows from that determination.
Explanation of Relevant Service Information
Airbus has issued Service Bulletins A310-27-2081 (for Model A310
series airplanes) and A300-27-6035 (for Model A300-600 series
airplanes), both dated November 26, 1996. These service bulletins
describe procedures for the installation of a modified hydraulic motor
that includes an improved camplate retention device and pin. The
effectivity of these service bulletins includes the airplanes affected
by the service bulletins that are required by the existing AD, and
includes additional airplanes. Accomplishment of the actions specified
in the service bulletins is intended to adequately address the
identified unsafe condition. The Direction Generale de l'Aviation
Civile (DGAC), which is the airworthiness authority for France,
classified these service bulletins as mandatory and issued French
airworthiness directive 97-081-217(B), dated March 12, 1997, in order
to assure the continued airworthiness of these airplanes in France.
FAA's Conclusions
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 airworthiness 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 96-01-52 to
continue to require, among other things, repetitive inspections to
ensure correct synchronization of the hydraulic control valves of the
THS actuator; replacement of the motors of the horizontal stabilizer
actuator with new or serviceable motors and resynchronization of the
valves, or adjustment of the synchronization, if necessary; and a
functional test of the THS. This proposed AD would add a requirement to
replace the THS actuator hydraulic motor with an improved motor.
Accomplishment of this replacement would constitute terminating action
for the repetitive inspection requirements. This proposed AD also would
expand the applicability of the existing AD to include additional
airplanes. The replacement of the motor with an improved motor would be
required to be accomplished in accordance with the service bulletins
described previously.
Difference Between the Proposed Rule and the French AD
Operators should note that, although the parallel French
airworthiness directive recommends accomplishing the modification by
August 31, 1998 (providing a compliance time of approximately 17
months), the FAA has determined that a 17-month compliance time would
not address the identified unsafe condition in a timely manner. In
developing an appropriate compliance time for this AD, the FAA
considered not only the recommendations by the DGAC, but the degree of
urgency associated with addressing the subject unsafe condition, the
average utilization of the affected fleet, and the time necessary to
accomplish the modification. In light of all of these factors, the FAA
finds a 12-month compliance time for accomplishment of the modification
to be warranted.
Cost Impact
There are approximately 88 airplanes of U.S. registry that would be
affected by this proposed AD.
The inspection currently required by AD 96-01-52, and retained in
this proposed AD, takes approximately 1 work hour per airplane to
accomplish, at an average labor rate of $60 per work hour. Based on
these figures, the cost impact of the requirements of the existing AD
on U.S. operators is estimated to be $5,280, or $60 per airplane, per
inspection cycle.
The new actions that are proposed in this AD action would take
approximately 4 work 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 of the new actions proposed by this AD on U.S.
operators is estimated to be $21,120, or $240 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.
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
[[Page 23692]]
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 39-9491 (61 FR
2697, anuary 29, 1996), and by adding a new airworthiness directive
(AD), to read as follows:
Airbus: Docket 97-NM-310-AD. Supersedes AD 96-01-52, Amendment
39-9491.
Applicability: Model A310 and A300-600 series airplanes on which
Airbus Modification 11607 has not been installed, 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 (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 desynchronization of the hydraulic control valves,
which could result in runaway of the horizontal stabilizer to its
full up or down position, subsequent reduced maneuvering capability,
and potential pitch upset, accomplish the following:
RESTATEMENT OF REQUIREMENTS OF AD 96-01-52:
(a) Within 12 days after February 5, 1996 (the effective date of
AD 96-01-52, amendment 39-9491), perform an inspection to ensure
correct synchronization of the hydraulic control valves of the
trimmable horizontal stabilizer (THS) actuator, in accordance with
paragraph 4.2.2.1 of Airbus All Operators Telex (AOT) 27-21,
Revision 1, dated January 5, 1996.
(1) If the actuator is synchronized correctly, prior to further
flight, perform a functional test of the THS in accordance with
paragraph 4.2.2.1 of the AOT. Thereafter, repeat the inspection
required by paragraph (a) of this AD at intervals not to exceed 500
hours time-in-service.
(2) If the actuator is desynchronized slightly, as specified in
the AOT, prior to further flight, adjust the synchronization, and
perform a functional test of the THS, in accordance with paragraph
4.2.2.2 of the AOT. Thereafter, repeat the inspection required by
paragraph (a) of this AD at intervals not to exceed 500 hours time-
in-service.
(3) If the actuator is desynchronized significantly, as
specified in the AOT, prior to further flight, accomplish either
paragraph (a)(3)(i) or (a)(3)(ii) of this AD. Prior to further
flight following the accomplishment of either of those paragraphs,
adjust the synchronization, and perform a functional test of the
THS, in accordance with paragraph 4.2.2.3 of the AOT. Thereafter,
repeat the inspection required by paragraph (a) of this AD at
intervals not to exceed 500 hours time-in-service.
(i) Remove and replace the hydraulic motors of the horizontal
stabilizer actuator (HSA) with new or serviceable motors in
accordance with procedures specified in the Airplane Maintenance
Manual. Or
(ii) Remove the hydraulic motors of the HSA and perform the
various follow-on actions specified in paragraph 4.2.2.4 of the AOT,
in accordance with that paragraph. (The follow-on actions include
checking the motors and the cam seats, assembling the motors, and
metal stamping the modification plate of the motors.) If any
discrepancy is found during the check, prior to further flight,
repair in accordance with paragraph 4.2.2.4 of the AOT.
(b) For airplanes on which any maintenance action relating to a
hydraulic motor or a hydraulic valve block of the HSA has occurred
since the airplane was new: Within 12 days after February 5, 1996,
accomplish either paragraph (b)(1) or (b)(2) of this AD.
(1) Replace both hydraulic motors of the HSA with new or
serviceable motors in accordance with the procedures specified in
the Airplane Maintenance Manual. Adjust the synchronization, and
perform a functional test of the THS in accordance with paragraph
4.2.2.3 of Airbus AOT 27-21, Revision 1, dated January 5, 1996.
Thereafter, perform the repetitive inspections required by paragraph
(a) of this AD at intervals not to exceed 500 hours time-in-service.
Or
(2) Remove the hydraulic motors of the HSA and perform the
various follow-on actions specified in paragraph 4.2.2.4 of the AOT,
in accordance with that paragraph of the AOT. Adjust the
synchronization, and perform a functional test of the THS in
accordance with paragraph 4.2.2.3 of the AOT. (The follow-on actions
include checking the motors and the cam seats, assembling the
motors, and metal stamping the modification plate of the motors.) If
any discrepancy is found during the check, prior to further flight,
repair in accordance with paragraph 4.2.2.4 of the AOT. Thereafter,
perform the repetitive inspections required by paragraph (a) of this
AD at intervals not to exceed 500 hours time-in-service.
NEW REQUIREMENTS OF THIS AD:
(c) Within 1 year after the effective date of this AD, replace
the hydraulic motors of the THS actuator with improved motors, in
accordance with Airbus Service Bulletin A310-27-2081 (for Model A310
series airplanes) or A300-27-6035 (for Model A300-600 series
airplanes), both dated November 26, 1996, as applicable.
Accomplishment of this action constitutes terminating action for the
repetitive inspection requirements of this AD.
(d) As of the effective date of this AD, no person shall install
on any airplane a THS actuator having part number 47142-201/-203.
(e)(1) 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.
(e)(2) Alternative methods of compliance, approved previously in
accordance with AD 96-01-52, amendment 39-9491, are approved as
alternative methods of compliance with paragraphs (a) and (b) of
this AD.
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.
(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.
Note 3: The subject of this AD is addressed in French
airworthiness directive 97-081-217(B), dated March 12, 1997.
Issued in Renton, Washington, on April 23, 1998.
Gary L. Killion,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-11435 Filed 4-29-98; 8:45 am]
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