TCAS

What does it look like? Does it work?

What it looks like

Here are 3 screenshots. The first two involve the standard Cirrus SF-50 and its TCAS display in the right-hand display. Other aircraft are shown as circles...empty circles, white circles, or yellow circles, depending on the level of attention the aircraft need. Here are too close calls in which you even have a visual on the other aircraft...bad piloting skills

The last screenshot shows the same TCAS display, X-Plane's internal map, and a screen of Little Navmap, all showing the same set of 16 planes around OMDB, with one approaching 30L (bottom right).

Near Hit
Very Close
TCAS, Map, Little Navmap
TCAS display of Cirrus SF-50
TCAS display of Cirrus SF-50
X-Plane's TCAS, X-Plane's internal Map, and Little Navmap showing AI aircrafts

No aircraft type or text information can be transferred via the multiplayer interfaces. That means that applications like internal map or Little Navmap take details like aircraft type and tail number from the plane type configured in X-Plane's AI settings, which is static and does not reflect the actual type of the live flight. That's why, especially visible in the third screenshot above, all planes are shown as "B737-800" with registration "N816NN": This is the tail number of X-Plane's standard B737 aircraft, which I had used as the type of the configured 19 AI aircraft.

Does it work?

The multiplayer library used by LiveTraffic (and XSquawkBox, X-IvAp, and others) simulates TCAS-related aircraft by using X-Plane's multiplayer (or "AI") aircraft. This is why - to be on the safe side - you have to configure the use of some multiplayer planes (see Installation - X-Plane Setting - AI Aircraft) and be conscious about the fact that only one plugin can control it (see parallel operations and the TCAS controlled menu item).

The multiplayer library positions the available AI aircraft (as many as configured, up to 19 possible) according to the nearest live traffic aircraft. The AI aircraft do not show up in the 3D world (due to a trick dealing with the phases of a frame redraw), but TCAS implementations and other tools requesting their positions will notice them. So remember: TCAS is not based on what you see outside your cockpit, but on smartly positioned invisible AI aircraft.

But the way TCAS is implemented inside the cockpit of add-ons varies by plane. This is beyond the control of LiveTraffic. E.g., some implementations are bound by the number of configured AI planes, others work even without. I received the following feedback on TCAS working or not:

Aircraft / Other Tool

OK?

X-Plane

OS

Requires AI planes

Laminar Cirrus SF-50

OK

10+11

Win+Mac

Yes

Rotate MD-88

OK

11

Mac

FlyJSim 732

OK

11

Win+Mac

Zibo mod B737

OK

11

Win

No

IXEG 737

OK

11

Win

Flight Factor A320

OK

11

Win

Reality XP GTN 650+750

OK

& Not OK

11

Win

X-TCAS (planes based on it)

OK

11

Win

No

X-Plane's internal map

OK

10+11

Win+Mac+Linux

Yes

Little Navmap (config)

OK

10+11

Win+Mac

Yes

Pilot 2 ATC

OK

11

Win

Yes

FSTramp

OK

11

Win

No

ABC - A Better Circle

OK

11

Win+Mac

No

No guarantees!