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

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.

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

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]

BILLING CODE 4910-13-U