AdvisoryU.S. Department of Transportation Federal Aviation Administration Circular Subject: Air Carrier Operational Approval and Date: 3/18/13 AC No: 120-55C Use of TCAS II Initiated by: AFS-400 Change: 1
1. PURPOSE. This advisory circular (AC) provides an acceptable, but not the only, means to address Traffic Alert and Collision Avoidance System (TCAS) issues related to installation and use of TCAS II regarding compliance with Title 14 of the Code of Federal Regulations (14 CFR) parts 121, 125, and 129 requirements for air carriers.
2. PRINCIPAL CHANGES. This change deletes Appendix 4, 14 CFR Part 129 Provisions for use of TCAS in U.S. Airspace, and adds information to Appendix 5, TCAS II Ground and Flight Training Requirements. Additionally, this change adds information about foreign air carriers relating to TCAS.
PAGE CONTROL CHART Remove Pages Dated Insert Pages Dated Pages 1, 2, 5, 6, 7, 8, 10, 11, 12, 2/23/11 Pages 1, 2, 5, 6, 7, 8, 10, 11, 12, 13, 3/18/13 13, 14, 15, and 16 14, 15, and 16 Appendix 1 Pages 1 and 2 2/23/11 Appendix 1 Pages 1 and 2 3/18/13 Appendix 2 Page 1 (and 2) 2/23/11 Appendix 2 Pages 1 and 2 3/18/13 Appendix 4 Page 1 (and 2) 2/23/11 Appendix 4 Page 1 (and 2) 3/18/13 Appendix 5 Page 1 (and 2) 2/23/11 Appendix 5 Pages 1 through 10 3/18/13 Appendix 6 Pages 1 through 10 2/23/11 Appendix 6 Pages 1 through 6 3/18/13 Appendix 7 Pages 1 through 6 2/23/11 ORIGINAL SIGNED by /s/ John M. Allen John M. Allen Director, Flight Standards Service
AdvisoryU.S. Department of Transportation Federal Aviation Administration Circular Subject: Air Carrier Operational Approval and Date: 3/18/13 AC No: 120-55C Use of TCAS II Initiated by: AFS-400 Change: 1
1. PURPOSE. This advisory circular (AC) provides an acceptable, but not the only, means to address Traffic Alert and Collision Avoidance System (TCAS) issues related to installation and use of TCAS II regarding compliance with Title 14 of the Code of Federal Regulations (14 CFR) parts 121, 125, and 129 requirements for air carriers.
2. APPLICABILITY. This AC applies to air carriers operating under part 121, other organizations conducting training approved in accordance with part 121 (e.g., training centers or aircraft manufacturers), operators under part 125, and foreign air carriers conducting operations in U.S. airspace under part 129. This AC also applies to those air carriers operating under 14 CFR part 135, § 135.180, as well as any aircraft operating under 14 CFR part 91 (including part 91 subpart K (part 91K)), where the operator chooses to install a TCAS II system meeting Technical Standard Order (TSO)-C119A, TSO-C119B, or TSO-C119C, TCAS II, Traffic Alert and Collision Avoidance System (TCAS) Airborne Equipment. This AC describes the TCAS operational approval process, acceptable methods for TCAS training, acceptable programs for maintenance, operational policies for TCAS use, appropriate actions in the event of a TCAS occurrence, and criteria for foreign operator use of TCAS in U.S. airspace. In addition, this AC addresses commonly asked TCAS questions in order to facilitate timely and consistent application of part 121, § 121.356, part 125, § 125.224, and part 129, § 129.18. It should be noted, however, the international standard for TCAS II, referred to as Airborne Collision Avoidance System (ACAS), includes the latest software version (v 7.1), as detailed by the International Civil Aviation Organization (ICAO).
3. CANCELLATION. This AC cancels AC 120-55B, Air Carrier Operational Approval and Use of TCAS II, dated August 22, 2001.
4. RELATED REGULATIONS AND GUIDANCE.
a. Title 14 CFR Regulations.
• Part 1, §§ 1.1 and 1.2;
• Part 71, §§ 71.9 and 71.33;
• Part 91, §§ 91.3, 91.123, 91.213, 91.215, 91.217, 91.219, 91.221, 91.413, and 91.703;
• Part 119, §§ 119.7 and 119.49;
• Part 121, §§ 121.345 and 121.356;
• Part 125, § 125.224;
• Part 129, §§ 129.5, 129.14, and 129.18; and
• Part 135, § 135.180.
b. Title 49 of the Code of Federal Regulationas (49 CFR). Part 830, §§ 830.5 and 830.15.
c. ICAO Guidance. Annex 6, Operation of Aircraft, 6.1.3, 4.2.3.1, and Appendix 2, 2.1.31.
5. DEFINITIONS. See Appendix 6 for definitions. For convenience, Appendix 6 repeats some definitions from other pertinent FAA references. Other definitions are unique to this AC and their application is limited to use with TCAS.
6. RELATED READING MATERIAL.
a. ACs (current editions). You can find ACs at http://www.faa.gov/regulations_policies/advisory_circulars. Inspectors can also access ACs through the Flight Standards Information Management System (FSIMS) at http://fsims.avs.faa.gov (see the link to http://rgl.faa.gov). Operators and the public may find this information at http://fsims.faa.gov (see the link to http://rgl.faa.gov).
• AC 20-131, Airworthiness Approval of Traffic Alert and Collision Avoidance Systems (TCAS II) and Mode S Transponders, and
• AC 20-151, Airworthiness Approval of Traffic Alert and Collision Avoidance Systems (TCAS II), Versions 7.0 & 7.1 and Associated Mode S Transponders.
b. TSOs. You can find TSOs through FSIMS at http://fsims.avs.faa.gov (see the link to http://rgl.faa.gov).
• TSO-C112C, Air Traffic Control Radar Beacon System/Mode Select (ATCRBS/Mode S) Airborne Equipment;
• TSO-C119A, Traffic Alert and Collision Avoidance System (TCAS) Airborne Equipment, TCAS II;
• TSO-C119B, Traffic Alert and Collision Avoidance System (TCAS) Airborne Equipment, TCAS II; and
• TSO-C119C, Traffic Alert and Collision Avoidance System (TCAS) Airborne Equipment, TCAS II with Optional Hybrid Surveillance.
NOTE: TSO-C119A, TSO-C119B, and TSO-C119C are in effect.
c. RTCA, Inc. Technical Standards Documents. These documents are available online at www.rtca.org or from the RTCA, Inc. Secretariat, 1150 18th Street NW, Suite 910, Washington, DC 20036.
• RTCA/DO-181E, Minimum Operational Performance Standards for Air Traffic Control Radar Beacon Systems (ATCRBS/Mode S) Airborne Equipment, and
• RTCA/DO-185A, Minimum Operational Performance Standards for Traffic Alert and Collision Avoidance System II (TCAS II).
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7. BACKGROUND. Approval of a TCAS for FAA type certificate (TC) or Supplemental Type Certificate (STC) is comprehensively addressed in AC 20-131 and AC 20-151. This AC provides information for U.S. air carriers, aircraft, and TCAS manufacturers; various inspectors; foreign air carriers operating in U.S. airspace; and other aviation organizations regarding standard means acceptable to the FAA to establish and ensure continued compliance with 14 CFR as related to TCAS. This information is intended to promote timely and comprehensive program implementation, to encourage development of standard practices for the application of TCAS, and to provide for suitable followup to TCAS events.
8. APPROVAL TO USE TCAS IN PART 121 OPERATIONS.
a. General.
(1) The use of TCAS in part 121 operations requires both FAA airworthiness certification and operational approval. Airworthiness certification of TCAS refers to an FAA approval of changes in an aircraft’s type design by amendment to a TC or issuance of an STC. Operational approval pertains to changes to training and maintenance programs, manuals, operational procedures, minimum equipment lists (MEL), and other areas necessary for safe and effective TCAS use and the qualification of aircrews through the approved training programs. An airworthiness TC/STC of a TCAS system alone does not constitute operational approval for use of the TCAS under the provisions of parts 121 and 135.
(2) The following are responsibilities of various FAA offices regarding a TCAS.
(a) FAA Aircraft Certification Offices (ACO) approve changes to a type design or issuance of STCs.
(b) FAA Aircraft Evaluation Groups (AEG) formulate operational criteria for specific aircraft types related to training, checking, maintenance, Master Minimum Equipment Lists (MMEL), or other operational issues, as necessary.
(c) FAA Flight Standards District Offices (FSDO) use information developed by the AEG to review a particular operator’s programs. FSDOs approve a particular operator’s training and maintenance programs, operational procedures, MELs, etc., provided they are consistent with criteria specified in the MMEL, Flight Standardization Board (FSB), Maintenance Review Board (MRB) reports, and policy guidance from the Flight Standards Service (AFS) Air Transportation Division (AFS-200), and Airworthiness Maintenance Division (AFS-300).
b. Airworthiness Approval. Criteria for TCAS airworthiness approval (TC or STC) are addressed by AC 20-131 and AC 20-151. TCAS installations are to be made in accordance with a type design change, an aircraft manufacturer’s FAA-approved Service Bulletin (SB), or by an STC.
c. Operational Approval.
(1) Approval Criteria. Operational approvals are based on criteria specified and, if applicable, training, maintenance, MMEL, or other operationally related criteria formulated by AEGs. If the criteria for training or checking are other than as specified, the criteria are available Par 7 Page 3
in FSB reports applicable to a particular aircraft type. The MMEL for each aircraft type specifies provisions for dispatch with inoperative equipment. Maintenance requirements are as identified in paragraph 11, except as otherwise described by an MRB report for a specific aircraft type, or in FAA-approved maintenance instructions identified in conjunction with an STC or manufacturer’s SB.
(2) Approval Methods. Accomplish TCAS operational approval through FAA approval of pertinent training programs, checklists, operations manuals, training manuals, maintenance programs, MELs, or other pertinent documents or document revisions applicable to the particular air carrier. An operator’s TCAS programs are usually approved for each specific aircraft type.
However, programs common to one or more types may receive approval if TCAS program elements are common to different aircraft types, such as the same TCAS or procedures.
(3) Approval Procedures.
(a) An FAA principal inspector (PI) issues approval to use a TCAS. Operators should make early contact with their respective PIs to ensure timely FAA response. Initiate such contact at the time preparations for TCAS selection or purchase, are underway and generally not later than TCAS TC/STC application.
(b) Operations specifications (OpSpecs) issuance is normally not required for U.S.
operators. The FAA reviews, accepts, and approves installations, training, maintenance programs, MELs, and other TCAS program elements in accordance with § 121.356.
9. PART 121 FLIGHTCREW QUALIFICATION FOR USE OF TCAS.
a. General.
(1) TCAS Qualification. Air carriers must ensure appropriate flightcrew TCAS qualification. The flightcrew must demonstrate proficiency in the following:
(a) Knowledge of TCAS concepts, systems, and procedures.
(b) Cognitive, procedural, and motor skills necessary to properly respond to TCAS advisories.
(2) Acceptable Qualification Methods. First-time TCAS qualification must be accomplished for each airplane type. Qualification may be accomplished during initial, transition, or upgrade ground and flight training programs with appropriate differences. This method will integrate TCAS information with other curriculum elements and modules. One may also accomplish first-time TCAS qualification as a stand-alone module of ground and flight training. Accomplish recurrent TCAS qualification during recurrent ground and flight training.
Recurrent ground training will be a stand-alone module. However, the TCAS will be fully integrated with the recurrent flight training during proficiency training (PT) or Line-Oriented Flight Training (LOFT). For first-time and recurrent TCAS qualification, an instructor will accomplish evaluation of TCAS objectives during training. There are no formal TCAS evaluation requirements for flight testing or checking. Include routine TCAS operations in all Page 4 Par 8
evaluation environments and check airmen/examiners should include TCAS as a routine discussion item.
b. TCAS Training Program Requirements.
(1) Curriculum. Appendix 5 contains the required areas of instruction for ground training for the first-time TCAS qualification. For subsequent airplane types training and for recurrent training, only the new, revised, or emphasized items need to be addressed. Appendix 5 also contains the objectives and related simulation characteristics required for flight training.
(2) Evaluation of TCAS Knowledge and Skills (Maneuvers).
(a) Evaluate TCAS knowledge with written, oral, or computer-based instructional tests. Combinations of these methods may be used if the required body of knowledge is completely covered. For any of these methods, one must achieve a passing grade of 90 percent.
First-time qualification in any type airplane must include evaluation of all knowledge areas. For recurrent training, complete coverage of the knowledge requirements must be completed every 36 months.
(b) An instructor must evaluate TCAS skills (maneuvers) for first-time TCAS qualification in each type airplane. An instructor may accomplish this evaluation in a TCAS-qualified flight training device (FTD), TCAS-qualified full flight simulator (FFS), or computer-based instruction (CBI) approved for each maneuver. For recurrent training, maneuver training must include response to all types of Resolution Advisories (RA) during any 36-month training period. Recurrent training is desirable in an FTD or simulator approved for the maneuvers.
c. Training Center Approval. Training centers conducting training, such as contract training or aircraft manufacturers, may have TCAS elements of those programs approved if the programs meet the curriculum requirements (ground and flight) provided in Appendix 5.
d. Initial Evaluation of TCAS Knowledge and Skills. Evaluate individual crewmembers’ TCAS knowledge and skills prior to TCAS use. Acceptable means of initial assessment include the evaluation by an authorized instructor or check airman using written, computer-based, or oral tests, and a simulator, FTD, or CBI system qualified to depict traffic encounters (a Level 4 can include the capability to depict traffic encounters).
e. TCAS Recurrent Training. Integrate TCAS recurrent training into other established recurrent training programs. Recurrent training for TCAS must include both ground and flight (maneuver) and should address any significant issues identified by line Operating Experience (OE), system changes, procedural changes, or unique characteristics such as the introduction of new aircraft/display systems or operations in airspace where high numbers of traffic advisories (TA) and RAs have been reported.
f. TCAS Recurrent Evaluation. Incorporate recurrent TCAS as an element of routine proficiency training.
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g. Line Checks and Route Checks. When using TCAS-equipped aircraft during line or route checks, check airmen should routinely incorporate proper TCAS use as a discussion item.
h. LOFT. LOFT programs using simulators equipped with TCAS should be enhanced by interaction with the TCAS. In addition, LOFT programs should consider proper crew vigilance for aircraft which may not be transponder or Mode C equipped. Advisories accomplished during LOFT are creditable toward first-time or recurrent qualification.
i. Crew Resource Management (CRM). CRM programs should address effective teamwork in responding to TCAS events with emphasis on the following areas:
(1) The crew should conduct preflight briefings on how to handle TCAS advisories.
(2) The proper reaction to a TA by the Pilot Flying (PF) and the pilot monitoring (PM).
10. OTHER OPERATIONAL ISSUES.
a. Manuals and Other Publications. Airplane flight manuals, operating manuals, maintenance manuals, general policy manuals, other manuals, publications, or written material (such as operating bulletins that may relate to TCAS use) must be appropriately amended to describe TCAS equipment, procedures, and operational policies according to the appropriate regulation.
b. MMEL/MEL.
(1) Operators formulate necessary TCAS revisions to their MELs for each particular fleet
(e.g., B-737, A320). MEL revisions must be consistent with the FAA MMEL established for each aircraft type. A summary of the process for addressing the necessary changes to MEL items, as well as examples of MMEL and acceptable MEL provisions for a TCAS, are in Appendix 3.
(2) The MMEL changed on April 6, 2002, and the relief category changed from C to B for the entire system.
c. Aircraft with TCAS Differences. Operators who have aircraft with TCAS differences in displays, controls, procedures, or that are involved with interchange operations must account for those TCAS differences. Accomplish this as part of an approved differences training program in accordance with § 121.418, or as otherwise specified in applicable FAA FSB reports concerning crew qualification pertaining to a particular airplane type.
d. Issues Unique to a Particular Operator. Operators should address any TCAS issues that may be unique to their particular route environment, aircraft, procedures, or TCAS display and control features. Examples include the following:
(1) Route Environment Issues. Air carriers having takeoffs or landings outside of the reference TCAS performance envelope (e.g., airport elevations outside of the range between sea level and 5,300 feet mean sea level (MSL) or having temperatures outside the range of International Standard Atmosphere (ISA) (±50° F)) should advise crews of appropriate Page 6 Par 9
procedures and precautions regarding RA compliance. To ensure proper response to the TCAS in limiting performance conditions (e.g., TCAS RA during takeoff climb or in final landing configuration at high-altitude airports such as Mexico City and La Paz), specific procedures or training may be necessary, unless a bulletin or manual information can adequately address these situations.
(2) Procedural Issues. Air carriers should describe the use of “TA-ONLY” when required on certain aircraft with an engine failure.
(3) Unique TCAS Issue. When the altimeter is set to reference zero feet at field elevation (QFE), the TCAS altitude display should be set to relative altitude (not absolute altitude or flight level) in order to minimize potential confusion.
e. Response to TCAS RA for Aircraft at Maximum Certified Altitude.
(1) Aircraft not inhibited to climb when at maximum certified altitude should climb in response to TCAS climb RAs.
(2) Aircraft that are climb-inhibited from TCAS climbs at maximum certified altitude will be issued a “DO NOT DESCEND” RA.
11. MAINTENANCE.
a. General. Maintenance procedures for TCAS receive approval or acceptance as part of an operator’s initial maintenance program approval or as a revision to that program. TCAS maintenance procedures should be consistent with the TCAS manufacturer’s maintenance procedures and/or aircraft manufacturer’s maintenance procedures for TCAS.
b. Maintenance Training. An operator must provide adequate TCAS maintenance training in accordance with the appropriate regulation to ensure that its maintenance personnel or contract maintenance personnel are able to properly implement TCAS-related maintenance programs.
This includes, but is not limited to, addressing installation, modification, correction of reported system discrepancies, and use of test equipment, procedures, MEL relief, and return-to-service (RTS) authorizations. The training procedures should address testing installed transponders and automatic pressure altitude reporting equipment on the ground in such a way that false targets are not generated in airborne TCAS systems. A method for eliminating potential interference with TCAS-equipped aircraft during transponder testing would be the use of shields for the transponder antennas. ACs 20-131 and 20-151 provide more detailed information and guidance concerning the proper procedures to follow when conducting operational testing of TCAS II or transponders on the ground.
c. TCAS Software Updates. When necessary, operators should ensure that appropriate TCAS software updates are incorporated. The latest version of software for TCAS II is version 7.1. To ensure compatibility with international standards, the FAA encourages the installation of this software as soon as practical. Software version 6.04A, version 7.0, and version 7.1 are all approved for operations in U.S. airspace.
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NOTE: ICAO Annex 10 requires version 7.1 software on new aircraft by January 1, 2014, and for existing aircraft by January 1, 2017. The European Union set an earlier equipage requirement that mandates version 7.1 software on new aircraft effective March 1, 2012, and for existing aircraft by December 1, 2015.
12. TCAS OPERATIONAL USE.
a. General. Each operator electing to use TCAS II should follow and implement those skills addressed and the guidance provided on TCAS training in paragraph 9.
NOTE: In no case should a pilot maneuver opposite to a TCAS RA.
b. Pilot Responsibilities. The intent of a TCAS is to serve as a backup to visual collision avoidance, application of right-of-way rules, and air traffic separation service. For TCAS to work as designed, immediate and correct crew response to TCAS advisories is essential. Delayed crew response or reluctance of a flightcrew to adjust the aircraft’s flightpath as advised by TCAS due to air traffic control (ATC) clearance provisions, fear of later FAA scrutiny, or other factors could significantly decrease or negate the protection afforded by TCAS. Flightcrews should respond to a TCAS in accordance with the following guidelines when responding to alerts:
(1) Respond to TAs by attempting to establish visual contact with the intruder aircraft and other aircraft which may be in the vicinity. Coordinate to the degree possible with other crewmembers to assist in searching for traffic. Do not deviate from an assigned clearance based only on TA information. For any traffic acquired visually, continue to maintain safe separation in accordance with current regulations and good operating practices.
(2) When an RA occurs, the PF should respond immediately by directing attention to RA displays and maneuver as indicated, unless doing so would jeopardize the safe operation of the flight or the flightcrew can ensure separation with the help of definitive visual acquisition of the aircraft causing the RA. By not responding to an RA, the flightcrew effectively takes responsibility for achieving safe separation. In so choosing, consider the following cautions:
(a) The traffic may also be equipped with TCAS and it may maneuver in response to an RA coordinated with your own TCAS.
(b) The traffic acquired visually may not be the same traffic causing the RA.
(c) Visual perception of the encounter may be misleading. Unless it is unequivocally clear that the target acquired visually is the one generating the RA and there are no complicating circumstances, the pilot’s instinctive reaction should always be to respond to RAs in the direction and to the degree displayed.
(3) Satisfy RAs by disconnecting the autopilot (AP) (if necessary) and auto throttle system (when required by the airframe manufacturer’s procedures), and using prompt positive control inputs in the direction and with the magnitude the TCAS advises. To achieve the required vertical rate (normally 1,500 feet per minute (fpm) climb or descent), first adjust the aircraft’s Page 8 Par 11
pitch using the suggested guidelines shown in the table below. Then refer to the vertical speed indicator (VSI) and make all necessary pitch adjustments to place the VSI in the green arc.
SPEED PITCH ADJUSTMENT .80 MACH 2° 250 knots indicated airspeed (KIAS) below 10,000 feet 4° APPROACH below 200 KIAS 5° to 7°
(a) On aircraft with pitch guidance for TCAS RA displays, follow the RA pitch command for initial, increase, reversal, and weakening RAs.
(b) For the TCAS to provide safe vertical separation, initial Vertical Speed (VS) response is required within 5 seconds of when the RA is first displayed. Excursions from assigned altitude, when responding to an RA, typically should be no more than 300 to 500 feet to satisfy the conflict. VS responses should be made to avoid red arcs or outlined pitch avoidance areas and, if applicable, to accurately fly to the green arc or outlined pitch guidance area.
(4) Respond immediately to any increase or reversal RA maneuver advisories. Initial VS response to an increase or reversal RA is expected by the TCAS within 2 1/2 seconds after issuance of the advisory. Again, avoid red arcs or outlined pitch avoidance areas and fly to the green arc or outlined pitch guidance area.
(5) The PM should advise the PF on the progress of achieving the vertical rates commanded by the TCAS. The PM and any onboard observers will assist in the visual search for the intruder and continue to cross-check the TCAS displayed information with other available traffic information to ensure the RA response is being flown correctly.
(6) If an initial corrective RA is downgraded or weakened, such as a “CLIMB” RA downgraded to a “DO NOT DESCEND” RA, pilots should respond to the weakening RA and adjust the aircraft’s VS to the rate depicted by the green (fly to) arc or line on the instantaneous vertical speed indicator (IVSI) or other suitable indicator, while keeping the needle or pitch guidance symbol out of the red arc or outlined pitch avoidance area. Pilots should remember that attention to the RA display and prompt reaction to the weakened RA will minimize altitude excursions and potential disruptions to ATC. This will allow for proper resolution of encounters and reduce the probability of additional RAs against the intruder or other traffic.
(7) Evasive maneuvering must be limited to the minimum required to comply with the RA. Excessive responses to RAs are not desirable or appropriate because of other potential traffic and ATC consequences. From level flight, proper response to an RA typically results in an overall altitude deviation of 300 to 500 ft in order to successfully resolve a traffic conflict.
(8) In some instances it may not be possible to respond to a TCAS RA and continue to satisfy a clearance at the same time. Even if a TCAS RA maneuver is inconsistent with the current clearance, respond appropriately to the RA. Since TCAS tracks all transponder-equipped aircraft in the vicinity, responding to an RA for an intruder assures a safe avoidance maneuver Par 12 Page 9
from that intruder and from other Mode C-equipped aircraft. Guidance in this paragraph does not conflict with that in subparagraph 12b(2).
(9) If a TCAS RA requires maneuvering contrary to right-of-way rules, cloud clearance rules for visual flight rules (VFR), instrument flight rules (IFR), or other such criteria, pilots should follow the TCAS RAs to resolve the immediate traffic conflict. Pilots should keep deviations from rules or clearances to the minimum necessary to satisfy a TCAS RA.
(10) If a TCAS RA response requires deviation from an ATC clearance, expeditiously return to the current ATC clearance when the traffic conflict is resolved, the TCAS “CLEAR OF CONFLICT” message is heard, or follow any subsequent change to clearance as advised by ATC. In responding to a TCAS RA that directs a deviation from assigned altitude, communicate with ATC as soon as practicable after responding to the RA. When the RA is cleared, the flightcrew should advise ATC that they are returning to their previously assigned clearance or should acknowledge any amended clearance issued. In addition, the flightcrew’s discretionary use of other types of reports may be desired. See Appendix 4 for suggested phraseology.
(11) If a TCAS RA maneuver is contrary to other critical cockpit warnings, pilots should respect those other critical warnings as defined by TCAS certification and training (that is, responses to stall warning, windshear, and ground proximity warning system (GPWS) take precedence over a TCAS RA, particularly when the aircraft is less than 2,500 feet above ground level (AGL)).
(12) Pilots should use TCAS traffic information displays to increase their awareness of nearby traffic and to assist in establishing visual contact with other aircraft. Certain electronic flight information system (EFIS) TCAS installations operating in conjunction with “track up” mode may require the pilot to make allowances for the difference between the aircraft heading and track when visually sighting nearby aircraft.
(13) Unless approved by the Administrator, pilots should operate TCAS while in flight in all airspace, including oceanic, international, and foreign airspace.
(14) When feasible, flightcrews should use the same altitude data source used by the PF to provide altitude information to TCAS and the ATC transponders. Using a common altitude source precludes unnecessary RAs due to differences between altitude data sources.
(15) Note and accurately report TCAS encounters and system anomalies in accordance with operator policies in order to make remedial improvements to TCAS or the National Airspace System (NAS).
NOTE: ARINC operates a Web-based data collection scheme on behalf of the FAA. The Web site can be found at www.tcasreport.com.
(16) The TCAS alone does not ensure safe separation in every case, nor diminish the pilot’s basic authority and responsibility to ensure safe flight. TCAS does not respond to aircraft which are not transponder-equipped or to aircraft with a transponder failure, and can display erroneous indications when a transponder malfunctions. TCAS RAs may, in some cases, conflict with flightpath requirements due to terrain, such as an obstacle-limited climb segment or an Page 10 Par 12