The T-CAS is an anticollision system and the pilot's sight. At velocities and high velocities, the pilot's vision can't manage to see another plane coming. And the T-CAS does this in 360 degrees, from any position that the airplane is coming, that could signify a risk of collision.
1. We are either dealing with a translation issue, or this reporter has no idea what he is talking about, and hasn't talked to any pilots or controllers to understand the system.
2. Why would one not turn on TCAS if one has it equipped?
3. Interesting to see an issue arising out of a communication failure (the "maintain" bit referring to altitude or flight plan ... which). I had thought that the terminology for altitude changes and assignments was standardized, as well as clearances. Also, clearance changes are usually presented in a standardized language.
I'd be grateful for explanation on that, in terms of variations in terminology.
Edited to fix silly spelling errors.
