TCAS I = pouze TA (Traffic Advisory). TCAS II = TA + RA (Resolution Advisory). TCAS III = budouci, koordinovane manevrování.
TCAS I = TA only. TCAS II = TA + RA. TCAS III = future, coordinated maneuvers.

RA MA VZDY PREDNOST pred pokyny ATC!
RA ALWAYS takes priority over ATC instructions!

Sensitivity Levels (SL) vs výška:
SL2: 1000-2350 ft AGL | SL3: 2350-5000 ft | SL4: 5000-10000 ft | SL5: 10000-20000 ft | SL6: 20000-42000 ft | SL7: >42000 ft

Logika Tau = cas do CPA (Closest Point of Approach), ne vzdálenost. TCAS pocita, za kolik sekund dojde ke kolizi.
Tau-based logic = time to CPA, not distance-based. TCAS calculates seconds to collision.

TA (Traffic Advisory): 25-48 s pred CPA (dle SL). Informuje pilota. Jantarovy symbol.
TA: 25-48 s before CPA (per SL). Informs pilot. Amber symbol.

RA (Resolution Advisory): 15-35 s pred CPA (dle SL). Prikazuje manévr. Cerveny symbol.
RA: 15-35 s before CPA (per SL). Commands maneuver. Red symbol.

TCAS dotazuje transpondéry Mode C/S. Bez transpondéru = neviditelny!
TCAS interrogates Mode C/S transponders. No transponder = invisible!

Koordinované RA: jeden letoun stoupá, druhy klesá (pres Mode S datalink).
Coordinated RAs: one aircraft climbs, other descends (via Mode S datalink).

Vrtulníky: nižší citlivost pri zemi, RA inhibováno pod urcitou výškou (typicky 1000 ft AGL). Nižší rychlosti = delší Tau.
Helicopters: lower sensitivity near ground, RA inhibited below certain altitude (typically 1000 ft AGL). Lower speeds = longer Tau.

ACAS = ICAO termin (Airborne Collision Avoidance System). TCAS = implementace (Honeywell).
ACAS = ICAO term. TCAS = implementation (Honeywell).