AD 95-26-15 R1

This amendment revises an existing airworthiness directive (AD), applicable to various transport category airplanes equipped with Allied Signal Commercial Avionics Systems CAS-81 TCAS, that 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 AD 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 amendment adds a revision of the AFM requirements that provides an alternative method of compliance with the currently required AFM revision; and provides for a modification to the TCAS processor, which, if accomplished, terminates the requirements of the AD.

Final rule.

95-26-15 R1 ALLIED SIGNAL COMMERCIAL AVIONICS SYSTEMS: Amendment 39-9824. Docket 96-NM-81-AD. Revises AD 95-26-15, Amendment 39-9495. \n\n\tApplicability: CAS-81 Traffic Alert and Collision Avoidance Systems (TCAS) installed in transport category airplanes, including but not limited to, the following airplane models, certificated in any category: \n\n\tAerospatiale Models ATR42 and ATR72 series airplanes; \n\n\tAirbus 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; \n\n\tBeech Models 1900 and BE-65 through -90 (inclusive) series airplanes; \n\n\tBoeing 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, 767-300, and 777-200 series airplanes; \n\n\tConvair Model CV-580 airplanes; \n\n\tde Havilland DHC-7 series airplanes and Model DHC-8-100 airplanes; \n\n\tEmbraer Model EMB-120 series airplanes; \n\n\tFairchild Model F227 airplanes; \n\n\tFokker Models F28 Mark 100, Mark 1000, and Mark 4000 series airplanes; \n\n\tGeneral Dynamics Models Convair 340 and 440 airplanes; \n\n\tGulfstream Models G-159 and G-IV airplanes; \n\n\tLockheed Model L1011 series airplanes; \n\n\tMcDonnell 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; \n\n\tRockwell International NA-265-65 airplanes; \n\n\tSaab Model 340 series airplanes; and \n\n\tShorts Model 360 series airplanes. \n\n\tNOTE 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. \n\n\tNOTE 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. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo 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: \n\n\t(a)\tExcept as provided by paragraph (b) of this AD: 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. \n\n\t"In order to ensure that the audio output of the CAS-81 TCAS operates properly, accomplish the following: \n\nPrior to the first flight of the day; prior to the accumulation of 10 hours of uninterrupted power; and at the mid-point of any one flight scheduled to exceed 10 hours of power: Cycle the power to the TCAS processor via the circuit breaker or power bus. \n\nPrior to taxi before takeoff: Initiate the TCAS functional test in accordance with AFM procedures to verify operational condition of the CAS-81 TCAS." \n\n\t(b)\tFor 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 specified in paragraph (a) of this AD: 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. \n\n\t"In order to ensure that the audio output of the CAS-81 TCAS operates properly, accomplish the following: \n\nPrior to each flight of up to 18 hours duration, reset the TCAS circuit breaker and conduct a TCAS self-test." \n\n\t(c)\tModification of the TPA-81A TCAS processor receiver in accordance with Allied Signal Service Bulletin TPA-81A-34-82, dated January 1996, or 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. \n\n\t(d)\tAn alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by theManager, 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. \n\n\tNOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Atlanta ACO. \n\n\t(e)\tSpecial 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. \n\n\t(f)\tThis amendment becomes effective on December 26, 1996.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by revising AD 95-26-15, amendment 39-9495 (61 FR 2699, January 29, 1996), which is applicable to various transport category airplanes equipped with Allied Signal Commercial Avionics Systems CAS-81 TCAS, was published in the Federal Register on June 5, 1996 (61 FR 28518). The action proposed to continue to require 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. The action also proposed to require 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.\n\n\tInterested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.\n\nSupport for the Proposal\n\tThree commenters support the rule.\n\nRequest to Cite Additional Service Instructions\n\tOne commenter requests that paragraph (c) of the proposed rule be revised to indicate that modification of the TPA-81A Traffic Alert and Collision Avoidance Systems (TCAS) processor may be accomplished either in accordance with Allied Signal Service Bulletin TPA-81A-34-82, dated January 1996, or with Allied Signal Service Bulletin TPA-81A-34-84, dated January 1996.\n\n\tThe FAA concurs, and has revised the final rule to reflect that the modification can be accomplished in accordance with either of the service bulletins.\n\nRequest to Specify Part Numbers of Affected Items\n\tOne commenter requests that the proposed rule specifically define the part numbers (by serial number) that are subject to the proposed requirements so that applicability could be established by using those serial numbers of the parts. The commenter states that using specific serial numbers to define applicability does not remove the burden of the manufacturers and operators to have a process that controls serial numbers.\n\n\tThe FAA does not concur. The requirements of this AD are applicable to all CAS-81 TCAS that are installed in any airplane. Therefore, there is no special need to cite every specific serial number manufactured. However, for the optional modification provided by this AD, the service bulletins that are cited in this action sufficiently define the applicable processor part numbers.\n\nRequest to Add Airplane Models to Applicability\n\tThis same commenter requests that the FAA add Boeing Model 777 series airplanes to the applicability of the proposed rule since the CAS-81 TCAS processors may be installed on that model.\n\n\tThe FAA concurs. The FAA points out, however, that this AD (as well as the previously issued AD) is applicable to thesubject TCAS unit itself, notwithstanding the model of airplane on which it is installed. As an aid to operators in identifying whether or not they may be subject to the rule, the FAA has included a list of the airplane models on which the TCAS unit is known to be installed.\n\n\tHowever, this list is not intended to include every airplane on which the TCAS may be installed. Operators are required to determine if the unit is installed on their airplanes, even if the airplane model does not appear on the list. The FAA has revised the wording of the applicability of the final rule to clarify this point.\n\nRequest to Correct Compliance Time for Paragraph (a)\n\tOne commenter notes that the compliance time in paragraph (a) of the proposed rule does not specify the number of hours that the airplane must not exceed at the mid-point of any one flight. In order to clarify this compliance time, the commenter requests that the phrase be changed to: ". . . and at the mid-point of any one flight scheduled to exceed 10 hours of power."\n\n\tThe FAA concurs. The FAA acknowledges that the specific number of hours that the airplane must not exceed at the mid-point of any one flight did appear in the originally issued AD 95-26-15, but was inadvertently omitted from paragraph (a) of the proposed rule. It was the FAA's intent that the requirement in the proposal in this regard be the same as that of the originally issued AD. The FAA, therefore, has corrected paragraph (a) of this final rule to include the phrase "10 hours of power" in the specified compliance time.\n\n\tAdditionally, certain other wording of the same AFM revision that appeared in paragraph (a) of the proposal was inadvertently omitted, and not identical to that which appeared in the originally issued AD 95-26-15. In the proposal, the wording describing the compliance time for cycling the power to the TCAS processor inadvertently stated, ". . . prior to the accumulation of 10 hours of power." However, that phrase should have been identical to what appeared in AD 95-26-15, which stated, ". . . prior to the accumulation of 10 hours of uninterrupted power." This correction has been made to the final rule.\n\nConclusion\n\tAfter careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the changes previously described. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.\n\nCost Impact\n\tThere 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 as many as 3,650 airplanes of U.S. registry may be affected by this AD.\n\n\tThe actions that are currently required by AD 95-26-15, and retained in this AD, 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.\n\n\tThe 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.\n\n\tShould an operator elect to accomplish the 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 on U.S. operators is estimated to be $180 per airplane.\n\nRegulatory Impact\n\tThe 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.\n\n\tFor 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 final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES."\n\nList of Subjects in 14 CFR Part 39\n\tAir transportation, Aircraft, Aviation safety, Safety.\n\nAdoption of the Amendment\n\tAccordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:\n\nPART 39 - AIRWORTHINESS DIRECTIVES\n\t1. The authority citation for part 39 continues to read as follows:\nAuthority: 49 U.S.C. 106(g), 40113, 44701.\n\n§ 39.13 - (Amended)\n\t2. Section 39.13 is amended by removing amendment 39-9495 (61 FR 2699, January 29, 1996), and by adding a new airworthiness directive (AD), amendment 39-9824, to read as follows: