approach to rising terrain. Since the basis for many approved instrument procedures and IFR clearances is avoiding high terrain or obstacles, it is particularly important that pilots maintain situational awareness (SA) and continue to use good operating practices and judgment when following TCAS RAs. Pilots should make frequent outside visual scans while using see-and-avoid techniques. Communication with ATC should be initiated as necessary.
c. Examples of Potential Consequences of Disregarding RA Information.
(1) An aircraft seen visually may not necessarily be the aircraft causing the RA or may not be the only aircraft to which TCAS is responding.
(2) It is difficult to visually determine the vertical displacement of other aircraft, especially when ground reference information is unreliable or at cruise altitudes where the Earth’s horizon is obscured. Therefore, disregarding RA information and maneuvering vertically based solely on visual acquisition may result in a loss of safe separation.
(3) ATC may not know when TCAS issues RAs. It is possible for ATC to unknowingly issue instructions that are contrary to the TCAS RA indications. Safe vertical separation may be lost during TCAS coordination when one aircraft maneuvers opposite the vertical direction indicated by TCAS and the other aircraft maneuvers as indicated by TCAS. As a result, both aircraft may experience excessive altitude excursions in vertical chase scenarios due to the aircraft maneuvering in the same vertical direction. Accordingly, during an RA, do not maneuver contrary to the RA based solely upon ATC instructions. ATC may not be providing separation service or be communicating with the aircraft causing the RA.
(4) Disregarding RA during a coordinated encounter with another TCAS II-equipped aircraft can result in loss of safe separation.
d. TCAS Good Operating Practices. The following are identified TCAS good operating practices:
(1) To preclude unnecessary transponder interrogations and possible interference with ground radar surveillance systems, do not activate TCAS (“TA-ONLY” or “TA/RA”) until taking the active runway for departure. A transponder selected to “XPNDR” or “ON” is adequate for ATC and nearby Automatic Dependent Surveillance-Broadcast (ADS-B)-equipped aircraft to “see” the aircraft while taxiing on the airport surface.
(2) Following landing and clearing of the runway, de-select TCAS from “TA-ONLY” or “TA/RA”. Select “XPNDR” or “ON” while taxiing to the ramp area. Upon shutdown, select “STBY” on the transponder.
(3) During flight, use TCAS displays to enhance SA. Use displays which have a range selection capability in an appropriate range setting for the phase of flight. For example, use minimum range settings in the terminal and longer ranges for climb/descent and cruise as appropriate.
(4) Note that TCAS RAs can occur while aircraft are legally separated.
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(5) It is appropriate to operate the TCAS in “TA-ONLY” in circumstances where unnecessary RAs frequently occur and where such RAs are disruptive to the operation of the aircraft. These circumstances may include:
(a) During takeoff towards known nearby traffic that is in visual contact and which could cause an unwanted RA during initial climb, such as a visually identified helicopter passing near the departure end of the runway. Select “TA/RA” after the potential for an unwanted RA ceases to exist, such as after climbing above a known VFR corridor.
(b) In instrument or visual conditions during approaches to closely spaced parallel runways (CSPR).
(c) In visual conditions, when flying in close proximity to other aircraft.
(d) At certain airports, during particular procedures, or in circumstances identified by the operator as having a significant potential for unwanted or inappropriate RAs.
(e) In the event of particular in-flight failures, such as engine failure, as specified by the Aircraft Flight Manual (AFM) or operator.
(f) During takeoffs or landings outside of the nominal TCAS reference performance envelope for RAs, as designated by the AFM or operator. TCAS reference performance for RAs is typically attainable during takeoffs and landings at airports within the envelope of ISA ±50 °F sea level to 5,300 feet MSL. When takeoffs or landings are outside of this envelope, use of “TA-ONLY” may be appropriate during the limited time period when TCAS reference performance cannot be achieved. This typically occurs when the aircraft is at low speed in specified limiting configurations during takeoff or landing at hot day, high-altitude airports, such as Mexico City or La Paz.
(6) When safe, practical, and in accordance with the air carrier’s approved operating procedures, pilots should limit VS to 1,500 fpm or less when within 1,000 feet of assigned altitudes. This procedure will reduce the frequency of unnecessary RAs and be in conformance with the Aeronautical Information Manual (AIM) and ICAO guidance.
e. Operator Responsibilities. Operators have the following general responsibilities regarding the TCAS:
(1) Ensure followup and evaluation of unusual TCAS events; and
(2) Periodically assess TCAS training, checking, and maintenance programs to ensure their correctness, pertinence, timeliness, and effectiveness.
f. ATC Responsibilities. Highlighted below are ATC responsibilities relating to TCAS.
(1) Controllers will not knowingly issue instructions that are contrary to RA guidance when they are aware that a TCAS maneuver is in progress. When an aircraft deviates from its clearance in response to an RA, ATC is still responsible for providing assistance to the deviating aircraft as requested until:
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• The pilot informs ATC that the RA conflict is clear; and the aircraft has returned to the previously assigned altitude; or
• Alternate ATC instructions have been issued and the pilot has acknowledged them.
NOTE: See Appendix 4 for suggested phraseology.
(2) Workload permitting, controllers may continue to provide pertinent traffic information in accordance with the current edition of FAA Order JO 7110.65, Air Traffic Control.
(3) Maintain awareness of TCAS programs and program changes.
(4) Train ATC specialists on TCAS and expected flightcrew responses to TCAS advisories and provide familiarization flights for specialists on TCAS-equipped aircraft to the extent possible.
(5) When requested by the flightcrew, and if appropriate, provide separation from TCAS-observed traffic and assistance in returning to the assigned clearance. Issue additional clearance instructions when the situation so requires.
(6) Advise pertinent FAA offices, such as a FSDO, via TCAS questionnaires about airspace or airports where excessive numbers of RAs occur. This facilitates initiation of corrective actions related to TCAS enhancements, TCAS procedures, and airspace adjustments.
Forward the information to www.tcasreport.com.
13. TCAS EVENT REPORTING.
NOTE: ARINC operates a Web-based data collection scheme on behalf of the FAA. The Web site can be found at www.tcasreport.com.
a. General. Operators and manufacturers are encouraged to develop procedures to ensure effective identification, tracking, and followup of significant TCAS-related events, as appropriate. Such procedures should focus on providing useful information to:
(1) Properly assess the importance of TCAS events.
(2) Follow up on information related to specific TCAS events, as necessary.
(3) Keep the industry and the FAA informed of the performance of TCAS in the NAS and in international operations.
b. Pilot Reports.
(1) Mandatory Report. As of March 8, 2010, a new National Transportation Safety Board (NTSB) immediate notification rule (§ 830.5) added the following to the list of reportable events that require immediate notification of the NTSB ACAS RAs issued either:
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• When an aircraft is being operated on an IFR flight plan and compliance with the advisory is necessary to avert a substantial risk of collision between two or more aircraft; or
• To an aircraft operating in Class A airspace.
(2) Other Reports.
(a) TCAS-Specific Reports. Pilots should make the following reports for TCAS RAs, as necessary.
1. Upon query from ATC, or after a deviation from an ATC clearance, make radio communications as appropriate to report a response to a TCAS advisory. Refer to AIM Chapter 4, Section 4, ATC Clearances and Aircraft Separation, for guidance, and Appendix 4 for recommended phraseology.
2. Reports, as specified by the operator, concerning TCAS anomalies, procedural difficulties, or system failures are typically made by pilots through one or more of the following methods:
• Pilot/observer questionnaire;
• Logbook entry and Aircraft Communications Addressing and Reporting System (ACARS); or
• Other records used by that operator, such as a captain’s report.
NOTE: An example of a typical reporting form for TCAS event information is shown in Appendix 2.
(b) Near Midair Collision (NMAC) Reports. Flightcrews should continue to submit NMAC reports in accordance with existing policies and procedures. Crews should be aware that there is no requirement to submit an NMAC report solely due to a TCAS event and that a TCAS report does not constitute an NMAC report.
(c) ATC Clearances and Instructions Reports. Unless required due to other circumstances, reports in compliance with § 91.123, compliance with ATC clearances and instructions reports, or regarding emergency deviation from an ATC clearance are not necessary solely as a result of a TCAS maneuver.
(d) Aviation Safety Reporting System (ASRS) Reports. The flightcrew may file ASRS reports at their discretion.
c. Maintenance Personnel Reports. Maintenance personnel should report TCAS problems that relate to system performance, manufacturers, and/or vendors to the appropriate principal avionics inspector (PAI).
d. TCAS Manufacturer Reports. TCAS avionics manufacturers report problems found with specific TCAS systems in accordance with established Service Difficulty Report (SDR) procedures. Report generic problems, such as those that may relate to the definition of collision Page 14 Par 13
avoidance system algorithms as defined by RTCA/DO-185, to the Aircraft Engineering Division (AIR-100) in Washington, DC.
14. FAA RESPONSE TO TCAS EVENTS. Regarding regulatory compliance issues, the FAA will not initiate enforcement action solely on the basis of a TCAS event. Letters of investigation will not be sent to pilots involved in a TCAS-related deviation, provided:
• The aircraft was equipped with a TCAS, the system was operable, and the equipment was turned on at the time of the event;
• The pilots have properly operated their aircraft in compliance with ATC clearances prior to the TCAS-related deviation;
• The pilots have successfully completed their air carrier’s FAA-approved TCAS training program; and
• The pilots have otherwise complied with the requirements of § 91.123.
15. FOREIGN AIR CARRIERS.
a. General. Section 129.18 requires TCAS II installation and use by certain foreign air carriers when operating in U.S. airspace. While most foreign states mandate TCAS II equipage in compliance with ICAO guidance found in ACAS Standards and Recommended Practices (SARPS), the FAA cannot require the installation and use of TCAS II for any foreign carrier aircraft or operation taking place outside of the U.S. 12 nautical mile (NM) territorial limit, even though a U.S. ATC facility may provide separation services.
b. TCAS Approval for Foreign Air Carriers. The FAA does not approve TCAS installation, training programs, MELs, or maintenance programs for foreign operators operating non-U.S.-registered aircraft. Such authorizations are addressed as specified by the State of Operator and by ICAO. Compatibility of TCAS and Mode S transponders with other aircraft and NAS facilities within U.S. airspace is essential. Compliance with these TCAS provisions ensures both TCAS system and procedural compatibility. A foreign air carrier must operate a TCAS-equipped aircraft in U.S. airspace, in accordance with §§ 129.18 and 129.5 and 49 CFR part 830, §§ 830.5 and 830.15. Each foreign air carrier and each foreign person operating a U.S.- registered aircraft within or outside the United States in common carriage must also comply with part § 129.14.
c. Mode S Transponders. Foreign air carrier(s) operating turbine-powered airplanes, as defined in § 129.18, must operate those airplanes with an appropriate Mode S transponder installed and operated on a suitable code specified by ATC during flight in U.S. airspace. In addition, the airplane must have a valid, unique, aircraft-specific ICAO 24-bit address assigned, and must have the Mode S transponder set to this address. Valid addresses are those consistent with the ICAO 24-bit address allocation plan contained in Annex 10, Volume III, Chapter 9, Aircraft Addressing System, and plan of the State of Registry for the specific aircraft. The unique ICAO 24-bit address, when properly set, may not be altered, set to a duplicated address, or set to an address that potentially interferes with ATC or TCAS safety functions (e.g., must not be set to all ones or all zeros, or the country address must not be set without the unique aircraft specific address).
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d. TCAS II Requirements. A TCAS II System capable of coordinating with TCAS units meeting TSO-C119A, TSO-C119B, or TSO-C119C must be installed. Except as provided for by MEL provisions acceptable to the State of Operator, the TCAS system must be operated in an appropriate TCAS mode during flight in U.S. airspace.
e. Standardization. Pilots must use training and procedures for use of TCAS, as specified by ICAO, this AC, or other equivalent criteria acceptable to the FAA, when operating in U.S.
airspace.
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Appendix 1 APPENDIX 1. ACRONYMS AND ABBREVIATIONS 14 CFR Title 14 of the Code of Federal Regulations 49 CFR Title 49 of the Code of Federal Regulations AC Advisory Circular ACARS Aircraft Communications Addressing and Reporting System ACAS Airborne Collision Avoidance System ACO Aircraft Certification Office AD Airworthiness Directive ADS-B Automatic Dependant Surveillance-Broadcast AEG Aircraft Evaluation Group AFM Aircraft Flight Manual AFS Flight Standards Service (F ederal Aviation Administration) AGL Above Ground Level AHRS Attitude and Heading Reference System AIM Aeronautical Information Manual AIR Aircraft Certification Service (FAA) ALIM Altitude Limit AP Autopilot ARINC Aeronautical Radio, Incorporated ASRS Aviation Safety Reporting System ATC Air Traffic Control ATCRBS ATC Radar Beacon System ATP Air Traffic Rules and Procedures Service (FAA) CAA Civil Aviation Authority CBI Computer-Based Instruction CFR Code of Federal Regulations CHDO Certificate-Holding District Office CPA Closest Point of Approach CRM Crew Resource Management CSPR Closely Spaced Parallel Runways DME Distance Measuring Equipment EFIS Electronic Flight Instrument System FAA Federal Aviation Administration FOEB Flight Opera tion Evaluation Board fpm Feet Per Minute FSB Flight Standardization Board FSDO Flight Standards District Office FTD Flight Training Device GPWS Ground Proximity Warning System ICAO International Civil Aviation Organization IFR Instrument Flight Rules IRS Inertial Reference System ISA International Standard Atmosphere IVSI Instantaneous Vertical Speed Indicator KIAS Knots Indicated Airpeed LOFT Line-Oriented Flight Training Page 1
Appendix 1 MEL Minimum Equipment List MMEL Master Minimum Equipment List MRB Maintenance Review Board MSL Mean Sea Level NAS National Airspace System NM Nautical Mile NMAC Near Midair Collision NSP National Simulator Program OE Operating Experience OpSpec Operations Specification PAI Principal Avionics Inspector PF Pilot Flying PI Principal Inspector PM Pilot Monitoring PMI Principal Maintenance Inspector POI Principal Operations Inspector PRM Parallel Runway Monitor PT Proficiency Training QFE Altimeter Reference to Zero Feet at Field Elevation QNH Altimeter Reference to Above Sea Level at Field Elevation RA Resolution Advisory RTCA Radio Technical Commission for Aeronautics SARPS Standards and Reco mmended Practices (ICAO) SB Service Bulletin SDR Service Difficulty Report STC Supplemental Type Certificate TA Traffic Advisory TC Type Certificate TCAS Traffic Alert and Collision Avoidance System TSO Technical Standard Order TTP TCAS Transition Programming UTC Universal Coordinated Time VFR Visual Flight Rules VSI Vertical Speed Indicator XPNDR Transponder ZTHR Altitude Threshold Page 2
________________ _______________________________________________________________________________________________________ Appendix 2 APPENDIX 2. SAMPLE TCAS PILOT EVENT QUESTIONNAIRE The FAA and the airline industry have established the TCAS Operational Performance Assessment (TOPA) program to assess the operational acceptability of TCAS in the NAS. Your participation in the program is essential to the success of the program. Please complete all items and return this questionnaire as quickly as possible. The information contained herein will be used only by the program participants to assess the operation of TCAS and will not be released to the public in a manner which allows the identification of you or the airline. The information WILL NOT be used to initiate or pursue enforcement action against you or the crew. Once the data is entered into the TOPA database, the questionnaire will be destroyed within 60 days.
NOTE: TCAS events may be reported electronically at www.tcasreport.com.
DATE: TIME: ______________ UTC A IRLINE:_____________ F LIGHT #: _____________ _____/_____/_____ A/C TYPE: TAIL NUMBER: ___________ O RIGIN: _________ D ESTINATION: __________ OWN ALTITUDE:_______________________________________ O WN POSITION:__________/__________/__________ FT
VOR RADIAL DME PHASE OF FLIGHT DEPARTURE (TAKEOFF TO 10,000 FT) C LIMB (10,000 FT TO TOC) CRUISE DESCENT (TOC TO 10,000 FT) A PPROACH (BELOW 10,000 FT) TCAS DISPLAY RANGE SETTING: 5 NM 10 NM 20 NM 30 NM OTHER __________ NM
INTRUDER AIRCRAFT ID (IF KNOWN):________________ TCAS-E QUIPPED (IF KNOWN)? YES NO RELATIVE ALTITUDE AT TA: _________FT CLOCK POSITION:____________ E ST. RANGE AT TA :____________NM WERE MULTIPLE TAS (AURALS) ISSUED ON THE SAME AIRCRAFT? Y ES NO IF YES HOW MANY?__________ RELATIVE ALTITUDE AT RA: _________FT CLOCK POSITION:____________ E ST. RANGE AT RA :____________NM WERE MULTIPLE RAS ISSUED ON THE SAME AIRCRAFT? Y ES NO IF YES HOW MANY?__________ ESTIMATED CLOSEST PROXIMITY RANGE ____________ NM ALTITUDE ____________ NM
INITIAL RA ISSUED CLIMB, CLIMB CLIMB, CLIMB, CLIMB DESCEND, DESCEND
LEVEL OFF, LEVEL OFF DESCEND, DESCEND, DESCEND CLIMB, CROSSING CLIMB DESCEND, CROSSING DESCEND ADJUST VERTICAL SPEED, R EDUCE CLIMB, REDUCE CLIMB REDUCE DESCENT. REDUCE
ADJUST DESCENT
MONITOR VERTICAL MAINTAIN VERTICAL SPEED, M AINTAIN VERTICAL SPEED, A DJUST VERTICAL SPEED,
SPEED MAINTAIN CROSSING MAINTAIN ADJUST DID THE INITIAL RA CHANGE ANY OF THE FOLLOWING?
ADJUST VERTICAL SPEED, ADJUST INCREASE CLIMB, INCREASE CLIMB INCREASE DESCENT, INCREASE DESCENT
CLIMB, CLIMB, NOW DESCEND, DESCEND NOW LEVEL OFF, LEVEL OFF
TYPE OF RA DISPLAY IN YOUR AIRCRAFT
IVSI PITCH CUES VERTICAL SPEED TAPE FOR THE ENCOUNTER, PLEASE INDICATE THE SEQUENCE OF EVENTS (E.G., ATC ADVISORY 1, VISUAL CONTACT 2, TA 3, RA 4) ATC ADVISORY:__________ TA:__________ RA:________ VISUAL CONTACT:__________
WAS THE RA FOLLOWED: YES NO NECESSARY FOR THE SITUATION: YES NO CONFLICT WITH ATC INSTRUCTIONS: YES NO RESULT IN A CLEARANCE DEVIATION: YES NO IF YES, WHAT WAS THE DEVIATION? _____________FT REMARKS: (PLEASE PROVIDE COMMENTS/CONCERNS ON THIS ENCOUNTER) Page 1
Appendix 2 SEND COMPLETED FORM BY MAIL OR FAX (215-493-0323) TO:
ARINC INCORPORATED
DANIEL TILLOTSON 14 TIMBER KNOLL DRIVE WASHINGTON CROSSING, PA 18977 DTILLOTS@ARINC.COM Page 2
Appendix 3 APPENDIX 3. TCAS MEL AND MMEL PROVISIONS
1. DISPATCHING WITH MEL PROVISIONS. Each operator with authority to dispatch an aircraft with a TCAS system or component temporarily inoperative must do so in accordance with provisions of an MEL. MELs are approved for each operator and type of aircraft, within provisions of the FAA MMEL for that type. When proposed MEL provisions are consistent with the FAA MMEL, POIs may approve the MEL. If requesting a less restrictive MEL or different MEL provisions, forward a proposal for consideration of an FAA MMEL change to the AEG assigned for that aircraft type. No relief will be granted for the voice command portion of the TCAS system when functioning in “TA-ONLY.” The audio will be provided via a speaker, which may also service windshear and ground proximity equipment. Enhanced features (those above and beyond the basic TCAS system) may be inoperative provided that the inoperative features do not degrade the system (for example, flight level traffic altitude selection feature for a traffic display).
2. BACKGROUND. The intent of the provisos and repair category intervals was to grant the operator sufficient relief, especially during the early stage of the TCAS transition, in order to promote the installation process, as well as support the use of a practical system. Both equipment reliability and operational experience dictated whether any revision to the MMEL relief was considered.
3. REVISIONS. The original Policy Letter 32 in the automated MMEL system outlined policy for TCAS II. On April 6, 2002 MMEL Policy Letter 32, revision 5 was issued as updated guidance to the FOEB for standardized MMEL relief for the TCAS. The most significant change in revision 5 is to change the relief category from C to B for the entire system when required by 14 CFR.
4. EXAMPLES. The following list is the standard set of provisos for all aircraft for which one grants relief for the TCAS I and II systems and it is extracted from MMEL Policy Letter 32, revision 7, dated July 7, 2006:
Appendix 3
TCAS MEL AND MMEL PROVISIONS TCAS I B | - | O | (M) (O) May be inoperative provided:
a) System is deactivated and secured; and
b) Enroute or approach procedures do not require its use.
C | - | O | (M) (O) May be inoperative provided:
a) Not required by 14 CFR;
b) System is deactivated and secured; and
c) Enroute or approach procedures do not require its use.
TCAS II B | - | O | (M) May be inoperative provided:
a) System is deactivated and secured; and
b) Enroute or approach procedures do not require its use.
C | - | O | (M) (O) May be inoperative provided:
a) Not required by 14 CFR;
b) System is deactivated and secured; and
c) Enroute or approach procedures do not require its use.
1) Combined TA and RA C | 2 | 1 | May be inoperative on the non-flying pilot side Dual Display System(s) provided:
a) TA and RA visual display is operative on the flying pilot side; and
b) TA and RA audio function is operative on the flying pilot side.
2) RA Display System(s) C | 2 | 1 | May be inoperative on non-flying pilot side:
C | - | O | (O) May be inoperative provided:
a) TA visual display and audio functions are operative;
b) “TA-ONLY” is selected by the crew; and
c) Enroute or approach procedures do not require its use.
3) Traffic Alert Display C | - | O | (O) May be inoperative provided:
System(s) a) RA visual display and audio functions are operative;
and
b) Enroute or approach procedures do not require its use.
4) Audio Functions B | 1 | O | a) Enroute or approach procedures do not require use of TCAS.