[Federal Register Volume 61, Number 109 (Wednesday, June 5, 1996)]
[Proposed Rules]
[Pages 28518-28520]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-14038]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-NM-81-AD]
RIN 2120-AA64


Airworthiness Directives; Allied Signal Commercial Avionics 
Systems CAS-81 Traffic Alert and Collision Avoidance Systems (TCAS) as 
Installed In, But Not Limited To, Various Transport Category Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to revise an existing airworthiness 
directive (AD), applicable to various transport category airplanes 
equipped with Allied Signal Commercial Avionics Systems CAS-81 TCAS. 
That AD currently requires a revision to the Airplane Flight Manual 
(AFM) to provide the flightcrew with procedures to cycle power to the 
TCAS processor via the circuit breaker or power bus, and to perform a 
TCAS functional test to verify proper operation of the TCAS. That 
action was prompted by reports of failure of the audio output of the 
CAS-81 TCAS. The actions specified by that AD are intended to ensure 
that the flightcrew is advised of the potential hazard associated with 
failure of the audio output of the CAS-81 TCAS, and of the procedures 
necessary to address it. This action would add a revision of the AFM 
requirements that would provide an alternative method of compliance 
with the currently required AFM revision; and would provide for a 
modification to the TCAS processor, which, if accomplished, terminates 
the requirements of the AD.

DATES: Comments must be received by July 15, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-81-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 Allied Signal Aerospace, Technical Publications, Dept. 
65-70, P.O. Box 52170, Phoenix, Arizona 85072-2170. This information 
may be examined at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: David Crew, Aerospace Engineer, 
Systems and Flight Test Branch, ACE-116A, FAA, Atlanta Aircraft 
Certification Office, Small Airplane Directorate, Campus Building, 1701 
Columbia Avenue, Suite 2-160, College Park, Georgia 30337-2748; 
telephone (404) 305-7335; fax (404) 305-7348.

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 96-NM-81-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. 96-NM-81-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    -On January 22, 1996, the FAA issued AD 95-26-15, amendment 39-9495 
(61 FR 2699, January 29, 1996), applicable to various transport 
category airplanes equipped with Allied Signal Commercial Avionics 
Systems CAS-81 Traffic Alert and Collision Avoidance Systems (TCAS). 
That AD requires a revision to the FAA-approved Airplane Flight Manual 
(AFM) to provide the flightcrew with procedures to cycle power to the 
TCAS processor via the circuit breaker or power bus, and to perform a 
TCAS functional test to verify proper operation of the TCAS. That 
action was prompted by reports of failure of the audio output of the 
CAS-81 TCAS. The requirements of that AD are intended to ensure that 
the flightcrew is advised of the potential hazard associated with 
failure of the audio output of the CAS-81 TCAS, and of the procedures 
necessary to address it.

Explanation of New Service Information

    -Since the issuance of that AD, Allied Signal has issued Service 
Bulletin TPA-81A-34-82, dated January 1996, which describes procedures 
for a modification (Unit Mod 13) of the TPA-81A TCAS processor 
receiver. This modification adds two 100k ohm resistors to circuitry on 
the voice synthesizer module (VSM) to provide a direct current (DC) 
return for the Op-Amp. Additionally, the modification adds four diodes 
to the ADV. INHIBIT #1, #2, #3, and #4 lines (advisory inhibit) at 
connector P3011 for isolation. This modification will eliminate audio 
noise and prevent a lack of AUDIO alert due to the absence of a return 
path to ground in an alternate current (AC) coupled filter in the VSM. 
The modification also will eliminate the need to isolate diodes of the 
advisory inhibit lines in certain configurations.
    -Allied Signal also issued Service Bulletin TPA-81A-34-84, dated 
January 1996, which describes procedures for modification of the TPA-
81A TCAS processor receiver. The modification involves redesignating 
(rolling) the part numbers of processors modified to Unit Mod 13. This 
modification will prevent failure of the

[[Page 28519]]

audio alert annunciation circuit when a unit has power applied for more 
than twelve hours at elevated temperatures.
    -The FAA has reviewed and approved these service bulletins, and has 
determined that accomplishment of these modifications will positively 
address the unsafe condition identified as failure of the audio output 
of the CAS-81 TCAS.

Comments Received in Response to AD 95-26-15

    -In response to the request for comments to AD 95-26-15, Airbus 
requests that the AD include a currently approved alternative means of 
compliance with the AFM revision required by paragraph (a) of the AD. 
For airplanes on which the manufacturer has substantiated 30 degrees 
Celsius as a maximum ambient temperature for the avionics compartment, 
this alternative method of compliance revises the Limitations Section 
of the FAA-approved AFM by including the following:

    In order to ensure that the audio output of the CAS-81 TCAS 
operates properly, accomplish the following:
    Prior to each flight of up to 18 hours duration, reset the TCAS 
circuit breaker and conduct a TCAS self-test.

    -The FAA concurs, and has added a new paragraph (b) to this 
proposal accordingly.
    Airbus also requests that additional information be added to the AD 
to clarify that maintenance personnel should perform the revisions to 
the AFM and should enter and sign-off the required actions into the 
logbook. -
    The FAA does not concur that this AD should be revised to include 
the additional information requested by the commenter. Persons 
authorized to perform the work required by an AD are generally not 
prescribed by an AD. Part 43 (``Maintenance, Preventive Maintenance, 
Rebuilding, and Alteration'') and part 121 (``Certification and 
Operations: Domestic, Flag, and Supplemental Air Carriers and 
Commercial Operators of Large Aircraft'') of the Federal Aviation 
Regulations (14 CFR parts 43 and 121) specify persons authorized to 
perform maintenance, preventive maintenance, rebuilding, and 
alterations, as well as maintenance record entry requirements, and 
approval for return to service of the airplane after maintenance.
    Additionally, Airbus requests that Models A300B2, A300B4, A310-200, 
A310-200, A300-600, A320-100, A320-200, A321-100, A330-300, A340-200, 
and A340-300 series airplanes be included in the list of airplanes 
included in the applicability of the AD.
    The FAA concurs. The FAA points out, however, that the proposed AD 
(as well as the previously issued AD) is applicable to the subject TCAS 
unit itself, notwithstanding the model of airplane on which it is 
installed. As an aid to operators in identifying whether or not they 
are subject to the rule, the FAA has included a list of the airplane 
models on which the TCAS unit is known to be installed. However, this 
list is limited in that it does not include every airplane on which the 
TCAS may be installed.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would revise AD 95-26-15 to add a new AFM requirement that 
would specify an alternative method of compliance with the currently 
required AFM revision. The proposed AD would provide for a modification 
of the TCAS processor, which, if accomplished, terminates the 
requirements of the existing AD. The proposed AD also identifies 
additional airplane models on which the subject TCAS unit may be 
installed.

Cost Impact

    There are approximately 5,000 various transport category airplanes 
in the worldwide fleet on which the subject TCAS unit may be installed. 
The FAA estimates that 3,650 airplanes of U.S. registry would be 
affected by this proposed AD.
    The actions that are currently required by AD 95-26-15, and 
retained in this proposed revision, take 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 existing AD on U.S. 
operators is estimated to be $219,000, or $60 per airplane.
    The cost impact figure discussed above is 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.
    Should an operator elect to accomplish the proposed optional 
terminating modification rather than continue using the AFM revision, 
it would take approximately 3 work hours per airplane to accomplish, at 
an average labor rate of $60 per work hour. Required parts would be 
furnished by the manufacturer at no cost to the operator. Based on 
these figures, the cost impact of this optional terminating action is 
estimated to be $180 per airplane.

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 39-9495 (61 FR 
2699, January 29, 1996), and by adding a new airworthiness directive 
(AD), to read as follows:

Allied Signal Commercial Avionics Systems: Docket 96-NM-81-AD. 
Revises AD 95-26-15, Amendment 39-9495.

    Applicability: CAS-81 Traffic Alert and Collision Avoidance 
Systems (TCAS) that are installed in, but not limited to, the 
following airplanes, certificated in any category:
    Aerospatiale Models ATR42 and ATR72 series airplanes;

[[Page 28520]]

    Airbus Industrie Models A300B2, A300B4, A310-200, A310-300, 
A300-600, A320-100, A320-200, A321-100, A330-300, A340-200, and 
A340-300 series airplanes;
    Beech Models 1900 and BE-65 through -90 (inclusive) series 
airplanes;
    Boeing Models 727-100, 727-200, 737-200, 737-300, 737-400, 737-
500, 747-100, 747-200, 747-300, 747-400, 747SP, 757-200, 767-200, 
and 767-300 series airplanes;
    Convair Model CV-580 airplanes;
    de Havilland DHC-7 series airplanes and Model DHC-8-100 
airplanes;
    Embraer Model EMB-120 series airplanes;
    Fairchild Model F227 airplanes;
    Fokker Models F28 Mark 100, Mark 1000, and Mark 4000 series 
airplanes;
    General Dynamics Models Convair 340 and 440 airplanes;
    Gulfstream Models G-159 and G-IV airplanes;
    Lockheed Model L1011 series airplanes;
    McDonnell Douglas Models DC-8-60, DC-9-31, DC-9-51, DC-10-10; 
DC-10-30, DC-10-30F, MD-11, and MD-80 series airplanes;
    Rockwell International NA-265-65 airplanes;
    Saab Model 340 series airplanes; and
    Shorts Model 360 series airplanes.

    Note 1: This AD applies to each airplane on which the TCAS unit 
identified in the preceding applicability provision has been 
installed, regardless of whether it has been otherwise modified, 
altered, or repaired in the area subject to the requirements of this 
AD. For affected TCAS units or 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 (d) 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.
    Note 2: CAS-81 Traffic Alert and Collision Avoidance Systems 
(TCAS) processors having serial numbers 6066 and subsequent, are not 
subject to the requirements of this AD.

    Compliance: Required as indicated, unless accomplished 
previously. -
    To ensure that the flightcrew is advised of the potential hazard 
associated with failure of the audio output of the CAS-81 TCAS, and 
of the procedures necessary to address it, accomplish the following:
    (a) Within 3 calendar days after February 5, 1996 (the effective 
date of AD 95-26-15, amendment 39-9495), revise the Limitations 
Section of the FAA-approved Airplane Flight Manual (AFM) to include 
the following. This may be accomplished by inserting a copy of this 
AD in the AFM.
    ``In order to ensure that the audio output of the CAS-81 TCAS 
operates properly, accomplish the following:
    <bullet> Prior to the first flight of the day; prior to the 
accumulation of 10 hours of power; and at the mid-point of any one 
flight scheduled to exceed hours: Cycle the power to the TCAS 
processor via the circuit breaker or power bus.
    <bullet> Prior to taxi before takeoff: Initiate the TCAS 
functional test in accordance with AFM procedures to verify 
operational condition of the CAS-81 TCAS.''
    -(b) For airplanes on which the manufacturer has substantiated 
30 degrees Celsius as a maximum ambient temperature for the TCAS 
processor location, the following is considered to be an alternative 
method of compliance for the AFM revision requirements: Revise the 
Limitations Section of the FAA-approved Airplane Flight Manual (AFM) 
to include the following. This may be accomplished by inserting a 
copy of this AD in the AFM. After revising the AFM, the AFM revision 
required by paragraph (a) of this AD may be removed from the AFM.
    ``In order to ensure that the audio output of the CAS-81 TCAS 
operates properly, accomplish the following:
    Prior to each flight of up to 18 hours duration, reset the TCAS 
circuit breaker and conduct a TCAS self-test.''
    -(c) Modification of the TPA-81A TCAS processor receiver in 
accordance with Allied Signal Service Bulletin TPA-81A-34-82, dated 
January 1996, and Allied Signal Service Bulletin TPA-81A-34-84, 
dated January 1996, constitutes terminating action for the 
requirements of this AD. After this modification is accomplished, 
the AFM revisions specified in paragraphs (a) and (b) of this AD may 
be removed from the AFM.
    -(d) 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, Atlanta Aircraft Certification 
Office (ACO), FAA, Small 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, Atlanta ACO.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Atlanta ACO.

    (e) 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 May 30, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-14038 Filed 6-4-96; 8:45 am]
BILLING CODE 4910-13-P