Re: @ John Robson
"Most autopilot is not capable of detecting objects or encroaching aircraft"
Most all commercial planes have RADAR and ADS-B is becoming more common. ADS-B broadcasts an aircraft's position, heading and speed that other aircraft and ground stations can pick up. That information could be used to avoid collisions. Planes flying IFR are being controlled from the ground normally and the autopilot keeps the plane flying as efficiently as possible. It unusual that two planes in class A airspace would be able to collide.
Biting the hand that feeds IT
