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TCAS. Introduction. What is TCAS? Big picture, How it works TCAS - Philosophy Training TCAS/- Future?. What is TCAS?. T raffic C ollision A voidance S ystem Situational awareness tool Shows other air traffic in the vicinity Collision avoidance Gives avoidance steering cues to pilots.
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Introduction • What is TCAS? • Big picture, How it works • TCAS - Philosophy • Training • TCAS/- Future?
What is TCAS? • Traffic Collision Avoidance System • Situational awareness tool • Shows other air traffic in the vicinity • Collision avoidance • Gives avoidance steering cues to pilots
How it works • IFF interrogator • Mode A, C and S • Components; • Computer • Mode S transponder • Antenna assembly • ATC/TCAS control panel • Traffic advisory indicator
How it works • Glossary: • Aircraft: Own, TCAS equipped aircraft • Intruder: Other traffic affecting our TCAS system
How it works TCAS TRSP. Request Intruder Aircraft
How it works Reply TCAS TRSP. Intruder Aircraft
How it works • The system needs to find relative; • Bearing • Range • Altitude
How it works • Bearing: Intruder
How it works • Range: Intruder
How it works • Altitude: Intruder Embedded in either mode C or S reply
How it works • Multiple requests: Establish "track"
How it works • Gives 3 different outputs depending on intruder equipment and range/bearing to intruder • Other traffic: • Situational awareness • Traffic Advisory: • Traffic within certain parameters, no steering • Resolution Advisory: • Traffic within certain parameters, Steering
How it works TCAS TA mA Aircraft Intruder
How it works TCAS RA mA mC TA mA Aircraft Intruder
How it works TCAS I RA TCAS RA mA mC TA mA Aircraft Intruder
How it works TCAS II Coord. RA TCAS I RA TCAS RA mA mC TA mA Aircraft Intruder
How it works Surveillance Volume 40 NM +/- 9900' TCAS
How it works Surveillance Volume 6 NM +/- 1200' TCAS
How it works TA RA 30-45 s Other traffic TCAS 20-30 s
How it works TA RA 30-45 s Other traffic TCAS 20-30 s Proximate traffic
Restrictions • Can only give vertical guidance because; • System only uses; • Altitude • Position • Closure rate • Vertical velocity to compute RA • No aspect capability
TCAS - Philosophy • TCAS increases safety! • TCAS JAR Req. 1 Jan 00 • Safety paramount in aviation • Technical solutions alone not enough
Breakdown in Quality system Checklist failure Unheeded warning Flaps omitted Degradation "breakdown" Deviation Amplification Error
Quality system Checklist works Effective warning Flaps omitted Normal operation Error Deviation Amplification
Training • Training requirement, • Initial CBT; 2 hours
TCAS / - Future? • 3D TCAS • Sensor Fusion • AP • RNAV • GPS • EGPWS • TCAS • Other?
IFF • What is IFF? • History • Modes
Hva er IFF? • Identification Friend or Foe • Military / Civilian use • Spörre puls / Svarpuls • 1030mhz / 1090 mhz • Består av interregator og transponder • En interrogator kan kommunisere med et antall transpondere
Hva er IFF? • The code signal sent by the interrogator system consists of two pulses spaced at a precisely defined interval. • A third pulse that has nothing to do with the coding of the query is actually used for interference suppression reasons. • The airborne transponder contains circuitry that discriminates between these various timings and automatically sends back the desired reply.
Hva er IFF? Request Interrogator Transponder Aircraft Radar Station
Hva er IFF? Request processed Interrogator Transponder Aircraft Radar Station
Hva er IFF? Reply Interrogator Transponder Aircraft Radar Station
Hva er IFF? Transponder Aircraft Interrogator Transponder Aircraft Radar Station Transponder Aircraft
Historikk • Germans used maneuvers at predetermined points to change radar echo • 1940: Transponders initially used in World War 2 on aircraft to identify the aircraft using IFF (Identify Friend or Foe) • MK I - Reply from incoming radar signal • MK III - Own interrogator / transponder
Historikk • 1960’s IFF for civilian use • 1980’s Mode S • Today Transponders are still used extensively on commercial aircraft to relay to the radar operators the height and identity of the aircraft on their radar displays.
Modes • Mode 3/A • Range / Bearing • Mode C • Altitude (100s of feet from CADC) • Mode S • Range / Bearing / Altitude / Datablock • Mode I/II/IV • Militärt bruk