Professional Pilot, March 2016

DISPLAYS KNOWLEDGE ADS B traffic in the cockpit More info is now available to you than ever before High proficiency with strict compliance is expected from pilots in this advanced ATC system Honeywell Primus Epic 2 has been selected by Embraer as the integrated avionics system for its 2nd generation E Jets In addition to ADS B In with Honeywells SmartTraffic TCAS the Epic 2 will provide datalink communication iNAV map and SVS for increased situational awareness O f all of the ADS B services that are currently being provided to aircraft traffic in the cockpit is one of the more complex aspects The end goal is to present the flightcrew with a single validated traffic target to include position velocity heading and vertical speed info in a manner that assists the crew in seeing and avoiding the traffic Because there are 3 protocols by which aircraft receive ADS B traffic as well as the fact that traffic position information for ATC can come from primary and secondary surveillance radar multilateration positioning and ground based ASDE X sources keeping all of this information aligned and 28 PROFESSIONAL PILOT March 2016 accurately fused into a single target in the cockpit is a challenge ADS B traffic in the cockpit Aircraft equipped with certified ADS B Out systems transmit their own position data once a second Any aircraft equipped with ADS B In operating on the same frequency may receive and display this traffic info This ADS B Direct traffic display is independent of any FAA ground provider and the reception range is only limited by the ability to receive If 2 or more aircraft transmit and receive on different frequencies 1090 MHz or 978 MHz and all of them are within range of the same FAA remote transceiver ground site they may see the other aircraft as traffic when the ground site rebroadcasts on the opposite frequency This ADS B Rebroadcast feature requires all participating aircraft to be within range of the same FAA ground site and there are limits on the service volume ADS R will display traffic It must be noted that ADS B Direct position information only requires In capability while Rebroadcast reception requires Out and In capability Traffic information services broadcast TIS B is advertised as the picture ATC sees transmitted to the cockpit Currently this positioning information can be made up of just radar or a combination of several different positioning systems TIS B will not provide positioning information on any aircraft that is not visible to an FAA ground surveillance system Multilateration In portions of Colorado and Alaska where radar will not work due to line of sight limitations multilateration MLAT is installed as a traffic surveillance system MLAT is a series of transceivers along the route of flight of the aircraft All MLAT transceivers in a group are synchronized to emit a highly accurate time signal and all in the group interrogate the target aircrafts transponder simultaneously The time of the signals return to the ground transceivers is slightly different to each unit and the resulting delta fixes the aircrafts position for ATC Displayed similarly to a radar position MLAT is certified as a stand alone system to separate traffic Typically radar and MLAT do not overlap for positioning Radar and ADS B positioning Currently Louisville Houston Philadelphia and Juneau TRACONs receive traffic both via radar and ADS B positioning from aircraft equipped with certified Out systems These 2 positioning sources are fused to provide the controller with a single val By Bill Gunn ATP CFII Compliance Manager State of Texas Aviation Division