TCAS question

[SFI145]

In an RA situation where one of the aircraft is flying at its ceiling does TCAS know this and would therefore be unable to issue a climb instruction?

[Bally Heck]

SFI145.

It is an option on TCAS fits to inhibit climb RAs under certain conditions. Climb performance restrictions at altitude being one of them. This can be done either by programming pins on the TCAS equipment or by inputs from the FMS.