What are the limits for TCAS to identify targets, in terms of distance and altitude?

Answer 1

There are no really "set" limits for TCAS to identify targets.

TCAS systems are generally limited to a 45nm mile forward range and significantly less to the sides and rear (to prevent excessive RF energy) - although this range can be shortened too in high-density traffic areas...

TCAS itself works not so much on a distance/altitude range alert, but on trends. It interrogates the other aircraft's transponders (Class C or S are most effective) to determine aircraft bearing, altitude, vertical speed, forward speed - in exactly the same manner ATC do with SSR.

The TCAS unit then processes this information and determines warnings on timings. That is, TCAS will work out relative bearings and find when the aircraft will either pass or collide. If the aircraft will pass outside the required separation standards, no warning is generated.

However if it passes inside the separation standards, TCAS will calculate the point of collision or at which the two aircraft will be closest. When the aircraft are 40 seconds from their closest passing point, TCAS generates an aural and visual "Traffic...Traffic" warning - or traffic advisory.

If the aircraft in question continue to close, at the 25 second point, TCAS (Mode II only) will generate a Resolution Advisory or RA. (TCAS Mode I can't generate RAs). An RA is comprised of instructions from TCAS to climb or descend to maintain separation.

TCAS cannot issue a change heading command - as it is less reliable for lateral separation so can only provide vertical.

The two aircraft's TCASs will "talk" - and work out different instructions - one to climb, the other to descend.

So basically in summary...TCAS doesn't work on set distance/altitude parameters but figures out closing rates and points of passing - and if they are less that required separation, will work on timings to collision/passing to alert crews - or provide emergency avoidance instructions.

Hope this helps! :-)

Answer 2

TCAS warns the pilot interior the cockpit whilst yet another plane is only too close to. The TCAS makes use of suggestions out of your transponder, so it does understand your and the different plane's altitude. It additionally knows of how a techniques the probability plane is. TCASII will recommend the two a climb or a descent avoidance action to the two plane. because of the fact of this TCAS could tell the pilot to descend from despite altitude they are at to evade the probability. If it replace into an emergency, i could decide for to bust my altitude to evade getting hit mid-air, although, you may wager that! while you're speaking approximately a sophisticated well-known aviation plane with TCAS and you're VFR and can see the community terrain, you will stay the FAA reg. above it yet you may desire to nonetheless descend decrease to evade a collision with yet another plane close to you and on the comparable time, evade the terrain.

Answer 3

2 mi; No altitude restriction

Answer 4

I think it might be different for each airplane. You can play vid. games, but I am not sure how accurate they are, i doubt very at all. That stuff might be secret due for safety reasons.

Answer 5

I have no clue. Its probably classified.