A319
Human-Machine Interface; Distraction; Communication Breakdown
ATC Issue All Types; Conflict NMAC
Air Traffic Control Issued New Clearance; Flight Crew Took Evasive Action
Procedure; Human Factors; Aircraft
On the designated arrival and in a NAV descent I saw traffic on the NAV display because an RA was imminent. Questioned the controller. He stated 'Turn left immediately and descend to 8;000 feet' at 200-300 feet separation visually acquired the aircraft. The TCAS had us at least 500 feet under him when he passed overhead? The ATC controller on 127.22 will have to be asked this question.
A pilot reports of not being issued traffic by ATC and observing traffic on the Navigation Display. The pilot questioned controller. The controller turned and descended aircraft. The pilot reported aircraft was 200-300 feet away when he spotted it and the aircraft passed 500 feet over the top.