[Federal Register Volume 62, Number 68 (Wednesday, April 9, 1997)]
[Proposed Rules]
[Pages 17131-17134]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-9016]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-41-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 all Airbus Model A310 and
A300-600 series airplanes, that currently requires a revision to the
Airplane Flight Manual (AFM) that warns the flight crew of certain
consequences associated with overriding the autopilot when it is in the
pitch control axis. That AD also requires modification of certain
flight control computers (FCC). That AD was prompted by the results of
an FAA review of the requirements of an earlier AD. This proposed
action would require a modification to the autopilot that would enable
the flight crew to manually disconnect the autopilot, regardless of its
mode and the altitude of the airplane; accomplishment of that
modification would terminate the current requirement to revise the AFM.
This proposed action also would require repetitive operational testing
of the modified autopilot to determine if the disconnect function
operates properly, and repair, if necessary. The actions specified by
the proposed AD are intended to prevent an out-of-trim condition
between the trimmable horizontal stabilizer and the elevator, which
could severely reduce controllability of the airplane.
DATES: Comments must be received by May 19, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 97-NM-41-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: Charles Huber, Aerospace Engineer,
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206)
227-2589; fax (206) 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
[[Page 17132]]
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-41-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-103, Attention: Rules
Docket No. 97-NM-41-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
On April 10, 1996, the FAA issued AD 96-08-07, amendment 39-9573
(61 FR 16873, April 18, 1996), which is applicable to all Airbus Model
A310 and A300-600 series airplanes. That AD requires a revision to the
Limitations Section of the FAA-approved Airplane Flight Manual (AFM)
that warns the flight crew about certain consequences of overriding the
autopilot when it is in the pitch control axis. That AD also requires
the modification of certain flight control computers (FCC).
The requirements of AD 96-08-07 are intended to prevent an out-of-
trim condition between the trimmable horizontal stabilizer and the
elevator, which could severely reduce controllability of the airplane.
Actions Since Issuance of Previous Rule
In the preamble of the proposal for AD 96-08-07, the FAA specified
that the actions proposed by that AD were considered interim action
because the manufacturer was developing a modification that will
positively address the unsafe condition described in the AD. The FAA
also indicated that it would consider further rulemaking action once
the modification was developed, approved, and available. The
manufacturer now has developed such a modification, and the FAA has
determined that further rulemaking is, indeed, necessary. This proposed
AD follows from that determination.
Explanation of Relevant Service Information
Airbus has issued Service Bulletin A310-22-2044, Revision 1 (for
Model A310 series airplanes), and Service Bulletin A300-22-6032,
Revision 1 (for Model A300-600 series airplanes); both dated January 8,
1997. These service bulletins describe procedures for modifying the
autopilot so that, by applying a counteracting force to the control
column, the flight crew can immediately disconnect the autopilot,
regardless of its mode and the altitude of the airplane.
Prior to the development of this modification, the flight crew,
under certain conditions, could not manually disconnect the pitch
control axis. Should the flight crew attempt to do so for an extended
time, that counteracting force would be interpreted by the autotrim as
a force to which it must respond, and the airplane would be trimmed
accordingly. Consequently, the trimmable horizontal stabilizer could
become significantly out-of-trim with the elevator.
Airbus also has issued Service Bulletin A310-22-2047 (for Model
A310 series airplanes), and Service Bulletin A300-22-6035 (for Model
A300-600 series airplanes); both dated July 16, 1996. These service
bulletins describe procedures for conducting repetitive operational
tests of the autopilot's disconnect function to determine if it is
working properly, and repair, if necessary. These actions are to be
accomplished after the autopilot has been modified in accordance with
Airbus Service Bulletin A310-22-2044, Revision 1, or Airbus Service
Bulletin A300-22-6032, Revision 1, both dated January 8, 1997, as
applicable.
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 (C/N) 96-150-
203(B), dated July 31, 1996, 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 96-08-07 to
continue to require a revision to the Limitations Section of the AFM
that warns the flight crew of certain consequences associated with
overriding the autopilot when it is in the pitch control axis, and
modification of certain FCC's.
The proposed AD also would require a modification to the autopilot
that would enable the flight crew to manually disconnect it, regardless
of the autopilot mode and the altitude of the airplane. After this
modification has been accomplished, the proposed AD would require
removal of the revision to the AFM that is currently required by AD 96-
08-07. In addition, the proposed action would require repetitive
operational testing of the modified autopilot to determine if the
disconnect function operates properly, and repair, if necessary. The
actions would be required to be accomplished in accordance with the
applicable service bulletins described previously.
Related AD Actions
Operators of Airbus Model A310 and A300-600 airplanes that are
subject to the requirements of AD 95-25-09, amendment 39-9455 (60 FR
63412, December 11, 1995) should be aware that certain FCC's must be
modified before or at the same time the requirements of this proposed
AD would be accomplished.
AD 95-25-09 requires modification of certain FCC's so that the
autopilot will disengage when the airplane is in the ``GO-AROUND'' mode
under certain conditions. The requirements of that AD are intended to
prevent an out-of-trim condition between the trimmable horizontal
stabilizer and the elevator, which may severely reduce controllability
of the airplane. That AD was prompted by an accident in which the
flight crew may have initiated an inadvertent ``go-around,'' which,
following several subsequent actions by the flight crew and automated
system, placed the airplane in a severe out-of-trim condition.
Cost Impact
There are approximately 77 Airbus Model A300-600 and A310 series
airplanes of U.S. registry that would be affected by this proposed AD.
The modification of certain FCC's that is currently required by AD
96-08-07 takes approximately 1 work hour per airplane to accomplish, at
an average labor rate of $60 per work hour. Required parts are supplied
by the manufacturer at no cost to operators. Based on these figures,
the cost impact
[[Page 17133]]
of the currently required modification on U.S. operators is estimated
to be $4,620, or $60 per airplane.
The AFM revision that is currently required by AD 96-08-07 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 currently required AFM revision on U.S. operators is
estimated to be $4,620, or $60 per airplane.
The modification of the autopilot that is proposed by this AD
action would take approximately 25 work hours per airplane to
accomplish, at an average labor rate of $60 per work hour. Required
parts would cost approximately $1,578 per airplane. Based on these
figures, the cost impact of the proposed modification on U.S. operators
is estimated to be $237,006, or $3,078 per airplane.
The operational test that is proposed by this AD action would take
approximately 7 work hours per airplane, per test cycle, to accomplish,
at an average labor rate of $60 per work hour. Based on these figures,
the cost impact of the proposed operational test on U.S. operators is
estimated to be $32,340 per test cycle, or $420 per airplane, per test
cycle.
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 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 39-9573 (61 FR
16873, April 18, 1996), and by adding a new airworthiness directive
(AD), to read as follows:
Airbus Industrie: Docket 97-NM-41-AD. Supersedes AD 96-08-07,
Amendment 39-9573.
Applicability: All Model A300-600 and A310 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
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 an out-of-trim condition between the trimmable
horizontal stabilizer and the elevator, which could severely reduce
controllability of the airplane, accomplish the following:
Restatement of Actions Required by AD 96-08-07, Amendment 39-9573
(a) Within 10 days after May 23, 1996 (the effective date of AD
96-08-07, amendment 39-9573), revise the Limitations Section of the
FAA-approved Airplane Flight Manual (AFM) to include the information
contained in paragraph (a)(1) or (a)(2) of this AD, as applicable.
This may be accomplished by inserting a copy of this AD in the AFM.
The AFM limitation required by AD 94-21-07, amendment 39-9049, may
be removed following accomplishment of the requirements of this
paragraph.
(1) For airplanes on which the flight control computers (FCC)
have not been modified in accordance with the requirements of
paragraph (b) of this AD:
``Overriding the autopilot (AP) in pitch axis does not cancel
the AP autotrim when LAND TRACK mode [green LAND on both Flight Mode
Annunciators (FMA)] or GO-AROUND mode is engaged. In these modes, if
the pilot counteracts the AP, the autotrim will trim against pilot
input. This could lead to a severe out-of-trim situation in a
critical phase of flight.''
(2) For airplanes on which the FCC's have been modified in
accordance with requirements of paragraph (b) of this AD:
``Overriding the autopilot (AP) in pitch axis does not cancel
the AP autotrim when LAND TRACK mode (green LAND on both FMA's) is
engaged, or GO-AROUND mode is engaged below 400 feet radio altitude
(RA). In these modes, if the pilot counteracts the AP, the autotrim
will trim against pilot input. This could lead to a severe out-of-
trim situation in a critical phase of flight.''
Restatement of Actions Required by AD 94-21-07, Amendment 39-9049
(b) For airplanes equipped with FCC's having either part number
(P/N) B470ABM1 (for Model A310 series airplanes) or B470AAM1 (for
Model A300-600 series airplanes): Within 60 days after November 2,
1994 (the effective date of AD 94-21-07, amendment 39-9049), modify
the FCC's in accordance with Airbus Service Bulletin A310-22-2036,
dated December 14, 1993 (for Model A310 series airplanes), or Airbus
Service Bulletin A300-22-6021, Revision 1, dated December 24, 1993
(for Model A300-600 series airplanes), as applicable.
(c) As of November 2, 1994, no person shall install a FCC having
either P/N B470ABM1 or B470AAM1 on any airplane.
New Actions Required by This AD
(d) For airplanes on which Modification No. 11454 [reference
Airbus Service Bulletin A310-22-2044 (for Model A310 series
airplanes) or Airbus Service Bulletin A300-22-6032 (for Model A300-
600 series airplanes)] has not been installed: Accomplish paragraphs
(d)(1), (d)(2)(i) and (d)(2)(ii) of this AD.
(1) Within 24 months after the effective date of this AD, modify
the autopilot in accordance with Airbus Service Bulletin A310-22-
2044, Revision 1, dated January 8, 1997 (for Model A310 series
airplanes), or Service Bulletin A300-22-6032, Revision 1, dated
January 8, 1997 (for Model A300-600 series airplanes), as
applicable. The requirements of paragraph (a) of AD 95-25-09,
amendment 39-9455, if applicable, must be accomplished prior to or
at the same time the requirements of this paragraph are
accomplished.
(2) Prior to further flight following accomplishment of
paragraph (d)(1) of this AD:
(i) Remove the AFM revisions required by paragraph (b) of this
AD; and
(ii) Perform an operational test of the autopilot disconnect to
determine if the
[[Page 17134]]
direct disconnect is operating properly, in accordance with Airbus
Service Bulletin A310-22-2047, dated July 16, 1996 (for Model A310
series airplanes), or Service Bulletin A300-22-6035, dated July 16,
1996 (for Model A300-600 series airplanes), as applicable. If any
discrepancy is detected, prior to further flight, repair it in
accordance with the applicable service bulletin. Repeat this test
thereafter at intervals not to exceed 18 months.
(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, 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 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Standardization Branch, ANM-113.
(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 April 2, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 97-9016 Filed 4-8-97; 8:45 am]
BILLING CODE 4910-13-U
