AC 120-55C Air Carrier TCAS - Code7700

More documents

Recommendations

Info

AC 120-55C 2/23/11should follow the TCAS RAs to resolve the immediate traffic conflict. Deviations from rules orclearances should be kept to the minimum necessary to satisfy a TCAS RA.(10) If a TCAS RA response requires deviation from an ATC clearance, expeditiouslyreturn to the current ATC clearance when the traffic conflict is resolved, the TCAS “clear ofconflict” message is heard, or follow any subsequent change to clearance as advised by ATC. Inresponding to a TCAS RA that directs a deviation from assigned altitude, communicate withATC as soon as practicable after responding to the RA. When the RA is cleared, the flightcrewshould advise ATC that they are returning to their previously assigned clearance or shouldacknowledge any amended clearance issued. In addition, the flightcrew’s discretionary use ofother types of reports may be desired. See Appendix 5 for suggested phraseology.(11) If a TCAS RA maneuver is contrary to other critical cockpit warnings, then thoseother critical warnings are respected as defined by TCAS certification and training (that is,responses to stall warning, windshear, and ground proximity warning system (GPWS) takeprecedence over a TCAS RA, particularly when the aircraft is less than 2,500 feet above groundlevel (AGL)).(12) Pilots should use TCAS traffic information displays to increase their awareness ofnearby traffic and to assist in establishing visual contact with other aircraft. Certain electronicflight 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 headingand track when visually sighting nearby aircraft.(13) Unless approved by the Administrator, pilots should operate TCAS while in-flightin all airspace, including oceanic, international, and foreign airspace.(14) When feasible, flightcrews should use the same altitude data source used by the PFto provide altitude information to TCAS and the ATC transponders. Using a common altitudesource precludes unnecessary RAs due to differences between altitude data sources.(15) Note and accurately report TCAS encounters and system anomalies in accordancewith operator policies so that remedial improvements to TCAS or the National Airspace System(NAS) can be made.NOTE: ARINC operates a Web-based data collection scheme on behalf ofthe FAA. The Web site can be found at www.tcasreport.com.(16) The TCAS does not alter or diminish the pilot’s basic authority and responsibility toensure safe flight. Since the TCAS does not respond to aircraft which are not transponderequipped or aircraft with a transponder failure, a TCAS alone does not ensure safe separation inevery case. TCAS RAs may, in some cases, conflict with flight path requirements due to terrain,such as an obstacle-limited climb segment or an approach to rising terrain. Since the basis formany approved instrument procedures and IFR clearances is avoiding high terrain or obstacles, itis particularly important that pilots maintain situational awareness (SA) and continue to use goodoperating practices and judgment when following TCAS RAs. Pilots should make frequentoutside visual scans while using see-and-avoid techniques. Communication with ATC should beinitiated as necessary.Page 10 Par 12
2/23/11 AC 120-55Cc. Consequences of Disregarding RA Information. The potential consequences ofdisregarding RA information include:(1) An aircraft seen visually may not necessarily be the aircraft causing the RA or maynot be the only aircraft to which TCAS is responding.(2) It is difficult to visually determine the vertical displacement of other aircraftespecially when ground reference information is unreliable or at cruise altitudes where theearth’s horizon is obscured. Therefore, disregarding RA information and maneuvering verticallybased 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 unknowinglyissue instructions that are contrary to the TCAS RA indications. Safe vertical separation may belost during TCAS coordination when one aircraft maneuvers opposite the vertical directionindicated by TCAS and the other aircraft maneuvers as indicated by TCAS. As a result, bothaircraft may experience excessive altitude excursions in vertical chase scenarios due to theaircraft maneuvering in the same vertical direction. Accordingly, during an RA, do not maneuvercontrary to the RA based solely upon ATC instructions.(4) ATC may not be providing separation service or be communicating with the aircraftcausing the RA.(5) Disregarding RA during a coordinated encounter with another TCAS-equippedaircraft can result in loss of safe separation.d. TCAS Good Operating Practices. The following are identified TCAS good operatingpractices:(1) To preclude unnecessary transponder interrogations and possible interference withground radar surveillance systems, do not activate TCAS (TA-only or TA/RA mode) until takingthe active runway for departure. A transponder selected to “XPDR” or “ON” is adequate forATC 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 or TA/RAmode. 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 rangeselection capability in an appropriate range setting for the phase of flight. For example, useminimum range settings in the terminal and longer ranges for climb/descent and cruise asappropriate.(4) Note that TCAS RAs can be generated while aircraft are legally separated.(5) It is appropriate to operate TCAS in the TA-only mode in circumstances whereunnecessary RAs frequently occur and where such RAs are disruptive to the operation of theaircraft. These circumstances may include:Par 12 Page 11
Page 1: U.S. Departmentof TransportationFed
Page 6: AC 120-55C 2/23/11g. Line Checks an
Page 9: 2/23/11 AC 120-55CSPEEDPITCH ADJUST
Page 13 and 14: 2/23/11 AC 120-55C(b) Alternate ATC
Page 15 and 16: 2/23/11 AC 120-55Cavoidance system
Page 17 and 18: 2/23/11 AC 120-55CAppendix 1APPENDI
Page 19: 2/23/11 AC 120-55CAppendix 2APPENDI
Page 22 and 23: AC 120-92A 2/23/11Appendix 3TCAS IT
Page 25: 2/23/11 AC 120-55CAppendix 5APPENDI
Page 28 and 29: AC 120-55C 2/23/11Appendix 6altitud
Page 30 and 31: AC 120-55C 2/23/11Appendix 6NOTE: I
Page 32 and 33: AC 120-55C 2/23/11Appendix 6(a) Oth
Page 34 and 35: AC 120-55C 2/23/11Appendix 6j. TCAS
Page 36 and 37: AC 120-55C 2/23/11Appendix 6towards
Page 38 and 39: AC 120-55C 2/23/11Appendix 711. Ini
Page 40 and 41: AC 120-55C 2/23/11Appendix 7c. Desc

AC 120-55C Air Carrier TCAS - Code7700

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?