[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]


-----------------------------------------------------------------------

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).

-----------------------------------------------------------------------

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