Originally Posted by
WHYEYEMAN
I was always taught from a very early stage that if you hear the words 'avoiding action' or 'immediately' associated with any ATC clearance then you disconnect the autopilot and 'just do it'. I have never practised it in recurrent sim sessions however which is a shame as it would take less than a minute to do as part of a LOFT excercise.
I am amazed that a standard safety call from ATC is not practiced in simulators. And from comments here avoiding action is often second guessed by flight crew -
whose lives are at risk due to their delay.
Most deconflictions are taken by planning the aircraft transits through the sector and the crew are unaware as they just follow the clearance they have received. However, when something goes awry the controller may have to act quickly and expects the aircraft to turn at once, there is no time for collaborative decision making and gentle FMC half rate turns.
TCAS is a really useful short term safety system but it will only see 'cooperating' aircraft that are transmitting/transponding on 1090/1030MHz. There have been mid-air collisions with one aircraft not transmitting. The controller almost always has a far better 'picture' of what is going on around the aircraft than the limited situation awareness of the flight crew who should not rely on TCAS to see everything. Time for second guessing is
after the avoiding action is completed