[Federal Register Volume 59, Number 3 (Wednesday, January 5, 1994)]
[Rules and Regulations]
[Pages 509-511]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 93-32113]


[[Page Unknown]]

[Federal Register: January 5, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 93-CE-46-AD; Amendment 39-8787; AD 94-01-05]

 

Airworthiness Directives: Allied Signal Aerospace Company, Air 
Transport Avionics (Formerly Bendix/King Air Transport Avionics 
Division) Traffic Alert and Collision Avoidance System II Processors

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
applies to certain Allied Signal Aerospace Company, Air Transport 
Avionics (Allied Signal) Traffic Alert and Collision Avoidance System 
(TCAS) II processors that are installed on aircraft. This action 
requires replacing the existing TCAS II processor with a new processor 
that incorporates updated computer logic. The development of candidate 
enhancements to TCAS II logic that improves its utility and increases 
its overall operational acceptance prompted the proposed action. The 
actions specified by this AD are intended to prevent collisions or near 
misses caused by incompatibility between the TCAS II processors and the 
current air traffic control system.

EFFECTIVE DATE: February 4, 1994.

ADDRESSES: Information that relates to this AD may be examined at the 
Federal Aviation Administration (FAA), Central Region, Office of the 
Assistant Chief Counsel, room 1558, 601 E. 12th Street, Kansas City, 
Missouri 64106.

FOR FURTHER INFORMATION CONTACT: Mr. A. E. Clark, Manager, Systems and 
Equipment Branch, FAA, Atlanta Aircraft Certification Office, 1669 
Phoenix Parkway, suite 210C, Atlanta, Georgia 30349; telephone (404) 
991-3020; facsimile (404) 991-3606.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations to include an AD that applies to certain Allied 
Signal TCAS II processors that are installed on aircraft was published 
in the Federal Register on September 9, 1993 (58 FR 47405). The action 
proposed to require (1) removing from service all processors that do 
not have computer logic ``Change 6.04A'' incorporated; and (2) 
mandatory incorporation of ``Change 6.04A'' into the TCAS II computer 
system.
    The affected TCAS II processors are not designed for a specific 
aircraft type. These Allied Signal TCAS II processors are installed on, 
but not limited to the following airplanes:
     Aerospatiale ATR-42;
     Airbus Industries A-340;
     Beech Model 65-A90 airplanes;
     Boeing 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;
     de Havilland DHC-7 series and Model DHC-8-100 airplanes;
     Fokker Models F.28 Mark 1000 and Mark 4000 airplanes;
     General Dynamics Models Convair 340 and 440 airplanes;
     Gulfstream Models G-159 and G-IV airplanes;
     Lockheed L1011 series airplanes;
     McDonnell Douglas--DC-8-60, DC-9-31, DC-9-51, DC-10-10 DC-
10-30, DC-13-30F, MD-11, and MD-80 series airplanes; and
     Rockwell International NA-265-65 airplanes.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received from 33 different owners, operators, 
manufacturers, and organizations.
    All commenters express their concern of the FAA's compliance date 
of December 30, 1993, especially since Allied Signal's service bulletin 
will not be available until early 1994. The following summarizes the 
compliance times that the commenters recommended:
     18 recommended one year or less;
     5 recommended longer than one year; and
     10 recommended an extension without a proposed time.

The National Air Traffic Controllers Association and the Airline Pilots 
Association both recommend an ``aggressive implementation'' of ``Change 
6.04A''. The FAA has re-evaluated the December 30, 1993, compliance 
time and has determined that the compliance time should be changed to 
December 31, 1994. In addition, ``Change 6.04A'' has been upgraded to 
``Change 6.04A Enhanced'', which eliminates unnecessary non-crossing 
resolution advisories (RA's) included in ``Change 6.04A''. Allied 
Signal has assured the FAA that (1) the upgrade to ``Change 6.04A 
Enhanced'' is minor and will be incorporated in the logic change for 
the TCAS II processor upgrades; and (2) this compliance time correlates 
with their schedule for disseminating service information and kits 
necessary to accomplish the incorporation of ``Change 6.04A Enhanced''. 
The proposed AD has been changed to reflect the compliance time change 
and logic change described above.
    In addition, Allied Signal states that ``Change 6.04'', which is 
FAA-certified and is currently in service, accomplishes the major 
intent of ``Change 6.04A Enhanced'' and should be considered as an 
acceptable interim version to allow the eventual upgrade to ``Change 
6.04A Enhanced''. The FAA recognizes that ``Change 6.04'' incorporates 
several of the features of ``Change 6.04A Enhanced''. However, the FAA 
has determined that (1) ``Change 6.04'' does not provide an equivalent 
level of safety to that of ``Change 6.04A Enhanced''; and (2) ``Change 
6.04A Enhanced'' should be incorporated as a way to prevent collisions 
or near misses caused by incompatibility between the TCAS II processors 
and the current air traffic control system. Compliance time extension 
consideration will be given on a case-by-case basis to airlines or 
operators experiencing compliance difficulties that arise because of 
fleet size. The proposed AD remains unchanged as a result of this 
comment.
    Allied Signal also lists several additional aircraft that these 
TCAS II processor units are certified for installation. The FAA has 
incorporated these into the proposed AD.
    One commenter, who supports the implementation of ``Change 6.04A 
Enhanced'', requests that the FAA issue a supplementary notice of 
proposed rulemaking (NPRM) to propose installing this revised software 
by June 30, 1995. This commenter states that significant differences 
exist between ``Change 6.04A'' and ``Change 6.04A Enhanced''. The FAA 
does not concur. Comments received in response to the proposed AD 
reflect unanimous support for implementing ``Change 6.04A Enhanced''. 
The FAA considers the logic change (which reduces non-crossing RA's) to 
be minor. The intent is to correct the unsafe condition by installing 
modified TCAS II computer units that incorporate updated logic. The FAA 
has determined that the requirement to implement Version 6.04A 
software, including the latest enhancement, will (1) correct the unsafe 
condition; (2) maintain the same intent originally proposed without 
altering the substance of the proposed rule; and (3) impose no 
additional burden on the public than was previously proposed.
    In addition, issuing a supplemental NPRM would necessitate (under 
the provisions of the Administrative Procedures Act) reissuing the 
notice, reopening the public comment period, considering any additional 
comments received, and eventually issuing a final rule. The time 
required for these procedures could take as long as four additional 
months. In light of this, and in consideration of the amount of time 
that has already elapsed since issuance of the original NPRM, the FAA 
concludes that soliciting further public comment is not necessary and 
that further delay of the final rule action is not appropriate.
    Several commenters request that the FAA revise the economic impact 
specified in the proposed AD to reflect costs associated with the 
development, testing prior to certification, and certification of the 
modified processor. These costs would be absorbed by suppliers, 
installers, and airline operators. The FAA does not concur that the 
economic impact statement include this information. The 1 workhour 
necessary to accomplish the proposed action was provided to the FAA by 
the TCAS II processor manufacturer based on the best data available to 
date. This number represents the time required to install the revised 
software. The cost analysis in AD rulemaking actions typically does not 
include costs associated with development, testing prior to 
certification, and certification of a modified processor. The proposed 
action remains unchanged as a result of these comments.
    After careful review of all available information including the 
comments noted above, the FAA has determined that air safety and the 
public interest require the adoption of the rule as proposed except for 
the change in compliance time, the logic reference change, the 
incorporation of known aircraft that these TCAS II processor units are 
installed on, and minor editorial corrections. The FAA has determined 
that these changes and corrections will not change the meaning of the 
AD nor add any additional burden upon the public than was already 
proposed.
    The FAA estimates that 3,000 TCAS II processors in the U.S. 
registry will be affected by this AD, that it will take approximately 1 
workhour per processor to accomplish the required action, and that the 
average labor rate is approximately $55 an hour. Based on these 
figures, the total cost impact of this AD on U.S. operators is 
estimated to be $165,000. These figures are based on the assumption 
that none of the operators of the airplanes equipped with the affected 
TCAS II processors have accomplished the actions specified in this AD.
    The regulations adopted herein will 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 final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final 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.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 14 CFR part 
39 of the Federal Aviation Regulations as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new AD:

93-01-05  Allied Signal Aerospace Company, Air Transport Avionics 
(formerly Bendix/King Air Transport Avionics Division): Amendment 
39-8787; Docket No. 93-CE-46-AD.

    Applicability: Traffic Alert and Collision Avoidance System II 
processors that are installed on, but not limited to the following 
airplanes (all serial numbers), certificated in any category:

Aerospatiale ATR-42;
Airbus Industries A-340;
Beech Model 65-A90 airplanes;
Boeing 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;
de Havilland DHC-7 series and Model DHC-8-100 airplanes;
Fokker Models F.28 Mark 1000 and Mark 4000 airplanes;
General Dynamics Models Convair 340 and 440 airplanes;
Gulfstream Models G-159 and G-IV airplanes;
Lockheed L1011 series airplanes;
McDonnell Douglas--DC-8-60, DC-9-31, DC-9-51, DC-10-10 DC-10-30, DC-
13-30F, MD-11, and MD-80 series airplanes; and
Rockwell International NA-265-65 airplanes.

    Compliance: Prior to December 31, 1994, unless already 
accomplished.
    To prevent collisions or near misses caused by incompatibility 
between the traffic alert and collision avoidance system (TCAS) II 
processors and the current air traffic control system, accomplish 
the following:
    (a) Remove any TCAS II processor with a part number (P/N) suffix 
listed in the ``Existing P/N Suffix'' column of the table below, and 
install a corresponding TCAS II processor with a P/N listed in the 
``New P/N Suffix'' column of the table below: 

------------------------------------------------------------------------
                                                                 New P/N
                     Existing P/N suffix                         suffix 
------------------------------------------------------------------------
-0102 or -0107................................................     -0108
-0203 or -0207................................................     -0208
-0301, -0302, or -0307........................................     -0308
-0402, -0405, or -0407........................................     -0408
-0504 or -0507................................................     -0508
-0606 or -0607................................................     -0608
-8101.........................................................     -0108
------------------------------------------------------------------------


    (b) Special flight permits may be issued in accordance with FAR 
21.197 and 21.199 to operate the airplane to a location where the 
requirements of this AD can be accomplished.
    (c) An alternative method of compliance or adjustment of the 
compliance times that provides an equivalent level of safety may be 
approved by the Manager, Atlanta Aircraft Certification Office, 1669 
Phoenix Parkway, Suite 210C, Atlanta, Georgia 30349. The request 
shall be forwarded through an appropriate FAA Maintenance Inspector, 
who may add comments and then send it to the Manager, Atlanta 
Aircraft Certification Office (ACO).

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

    (d) Information that relates to the proposed AD may be examined 
at the FAA, Central Region, Office of the Assistant Chief Counsel, 
Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.
    (e) This amendment (39-8787) becomes effective on February 4, 
1994.

    Issued in Kansas City, Missouri, on December 29, 1993.
Gerald W. Pierce,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 93-32113 Filed 12-30-93; 8:45 am]
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