CNN reported yesterday (September 24) that the FAA was investigating an incident involving passenger injuries resulting from a midair collision warning. UAL Flight 2428 from Newark, New Jersey, to San Francisco International Airport responded to a traffic collision avoidance system (TCAS) resolution advisory (RA) and “slowed its descent to account for another aircraft at a lower altitude,” according to the FAA.
You have gotten both with TCAS. ADS-B, especially the more reliable UAT, gives up to 2-minute conflict alert, 2-5 degree heading change resolution. Zero passenger awareness. Where is the problem? Oh yes. Controllers are worried about their jobs. With primary separation in the cockpit instead of on the ground, as backup, the current controllers could handle all traffic, not just IFR. A little bird told me this is gonna happen, but too slowly.
I have responded to RA’s also. According to the training I have had, there is no reason for excessive maneuvering to respond to any RA, if action taken immediately when the RA is indicated. If response is late or not in accordance of the RA, that is a pilot issue. Descending in excess of 1500 fpm will set off an RA that could have been avoided if not descending so fast.
TCAS is much more reliable than any ADS-B readout. Also the FAR’s require pilots to follow any RAs even if it is not in accordance to any ATC clearance.