Airworthiness Directives; Thales Avionics Traffic Advisory/Resolution Advisory (TA/RA) Vertical Speed Indicator-Traffic Alert and Collision Avoidance System (VSI-TCAS) Indicators, Installed on but not Limited to Certain Transport Category Airplanes Equipped With TCAS II Change 7 Computers (ACAS II)

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Thales Avionics TA/RA VSI-TCAS indicators, installed on but not limited to certain transport category airplanes equipped with TCAS II change 7 computers (ACAS II). This proposal would require a revision to the Airplane Flight Manual (AFM) to advise the flightcrew to follow the audio annunciation when an RA fail message is triggered during a multi-aircraft encounter. This proposed AD would also require modification of the software for the TA/RA VSI-TCAS indicator, which would terminate the requirement for the AFM revision. This action is necessary to prevent the TA/RA VSI-TCAS indicator from displaying a conflicting “RA FAIL” message during a multi-aircraft encounter, which could result in the flightcrew ignoring the correct aural command and traffic display information if the flightcrew believes the TCAS II computer has malfunctioned, and consequently lead to a mid-air collision with other aircraft. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by June 7, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2002-NM-284-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to (425) 227-1232. Comments may also be sent via the Internet using the following address: 9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must contain “Docket No. 2002-NM-284-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 or 2000 or ASCII text.

The service information referenced in the proposed rule may be obtained from Thales Avionics, Air Transport Avionics, 105 avenue du General Eisenhower, BP 1147, 31036 Toulouse Cedex 1, France; or Thales Avionics, Regional and Business Aircraft Avionics, 105 avenue du General Eisenhower, BP 1147, 31036 Toulouse Cedex 1, France; or Thales Avionics, Avionics for Military Aircraft, Rue Toussaint Catros, 33187 Le Haillan Cedex, France. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California.

FOR FURTHER INFORMATION CONTACT:

Abby Malmir, Aerospace Engineer, Systems and Equipment Branch, ANM-130L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone (562) 627-5351; fax (562) 627-5210.

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 action may be changed in light of the comments received.

Submit comments using the following format:

• Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
• For each issue, state what specific change to the proposed AD is being requested.
• Include justification (e.g., reasons or data) for each request.

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 action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2002-NM-284-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-114, Attention: Rules Docket No. 2002-NM-284-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The FAA has become aware of an unsafe condition that may exist with Thales Avionics traffic advisory/resolution advisory (TA/RA) vertical speed indicator-traffic alert and collision avoidance system (VSI-TCAS) indicators, installed on but not limited to certain transport category airplanes equipped with TCAS II change 7 computers (ACAS II). During a ground test, the TA/RA VSI-TCAS indicator did not display the “DON'T CLIMB, DON'T DESCEND” RA command, under the scenario where the airplane is located between two other aircraft (one above and one below). Instead, the TA/RA VSI-TCAS indicator displayed an “RA FAIL” message, which conflicted with both the correct audio annunciation to “MAINTAIN VERTICAL SPEED, MAINTAIN” and traffic display information. A conflicting “RA FAIL” message during a multi-aircraft encounter, if not corrected, could result in the flightcrew ignoring the correct aural command and traffic display information if the flightcrew believes the TCAS II computer has malfunctioned, and consequently lead to a mid-air collision with other aircraft.

Explanation of Relevant Service Information

Thales Avionics has issued the following service bulletins:

These service bulletins describe procedures for modification of the software for the TA/RA VSI-TCAS indicator. The modification involves reprogramming memory MN9 of the graphic processor board for the TA/RA VSI-TCAS indicator, and reidentifying and testing the modified TA/RA VSI-TCAS indicator. Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition. The Direction Generale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, classified this service bulletin as mandatory and issued French airworthiness directive F-2004-042, dated March 31, 2004, to ensure the continued airworthiness of these airplanes in France.

FAA's Conclusions

This TA/RA VSI-TCAS indicator is manufactured in France and is 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.

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 require revising the Limitations Section of the Airplane Flight Manual (AFM) to advise the flightcrew to follow the audio annunciation when an RA fail message is triggered during a multi-aircraft encounter. This proposed AD would also require modifying the software for the TA/RA VSI-TCAS indicator, which would terminate the requirement for the AFM revision. The terminating action is required to be accomplished in accordance with the service bulletins described previously, except as discussed below.

Difference Between Proposed AD and French Airworthiness Directive

Operators should note that affected part number (P/N) 457400SB0711, as listed in Thales Avionics Service Bulletin 457400-34-083, Revision 03, dated January 26, 2004, was inadvertently omitted from French airworthiness directive F-2004-042, dated March 31, 2004. We have determined that the omitted part number is subject to the same unsafe condition of this proposed AD and, therefore, have included P/N 457400SB0711 in this proposed AD. Additionally, the DGAC has informed us that it plans to revise the French airworthiness directive to include the omitted part number.

Clarification Between Proposed AD and French Airworthiness Directive

The French airworthiness directive requires revising the Limitations Section of the AFM by inserting a temporary limitation. We have reviewed the language of the temporary limitation and determined that certain wording does not conform to the U.S. standard of writing AFM flightcrew instructions in either “must do” or “do not” statements for clarity and memorization. While we have clarified the language of the temporary limitation in this proposed AD, the intent of it remains the same.

Cost Impact

We do not know how many aircraft, equipped with Thales Avionics TA/RA VSI-TCAS indicators and TCAS II change 7 computers (ACAS II), of the affected design are in the worldwide fleet or on the U.S. Register. We do, however, know that it would take approximately 2 work hours per airplane to accomplish the proposed actions, and that the average labor rate is $65 per work hour. Required parts, for 2 TCAS displays per airplane, would cost approximately between $1,316 and $1,826 per airplane. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be between $1,446 and $1,956 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. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact

The regulations proposed herein would not have a substantial direct effect 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, it is determined that this proposal would not have federalism implications under Executive Order 13132.

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.