Tcas threats

[tubby linton]

How many threats is a standard Tcas meant to be able to deal with simultaneously? I think that it is eight but I can no longer find the reference.

[underfire]

Depending on your point of reference as a threat...

"TCAS II was designed to operate in traffic densities of up to 0.3 aircraft per square nautical mile (nmi), i.e., 24 aircraft within a 5 nmi radius, which was the highest traffic density envisioned over the next 20 years."

FAA Intro to TCAS (http://www.faa.gov/documentLibrary/media/Advisory_Circular/TCAS%20II%20V7.1%20Intro%20booklet.pdf) 2011

According to Honeywell data (https://www.bendixking.com/HWL/media/Pilot-Guides/006-08499-0000_7.pdf):

"TCAS II can track as many as 45 aircraft, display up to 30 of them and can coordinate a resolution advisory for up to three intruders at once. The advisories are always based on the least amount of deviation from the flight path while providing safe vertical separation" (emphasis added)

[Dont Hang Up]

Underfire

I have taken the liberty of borrowing your reference for a similar question on another thread. Thanks.

http://www.pprune.org/questions/569901-how-many-escape-manoeuvres-acas-equipment-can-calculate-simultaneously.html#post9200555

[underfire]

No problem!

Here are other sources....

http://i67.tinypic.com/mncjp.jpg

Honeywell TCAS II Change 7.1 (https://aerospace.honeywell.com/~/media/Brochures/N61-1168-000-001_TCAS-Whitepaper)