Definition
A phrase used by air traffic control to inform a pilot that previously issued traffic is no longer being observed on the controller's radar display. It does not mean the traffic has departed the area — only that the controller can no longer see it on radar.
Plain English
ATC is telling you that the other aircraft they were warning you about has dropped off their radar screen. The aircraft might still be out there; the controller just can't see it anymore.
Context Anchor
Heard on the radio after air traffic control has already warned you about nearby traffic.
Why Pilots Care
Tells the pilot they must now rely on their own visual scan or other separation methods rather than expecting continued ATC updates on that aircraft.
Intuition Check
Do not hear this as “the traffic is gone.” Hear it as “the controller no longer sees it, so you still need to look.”
Example Sentence 1
After the controller called out converging traffic, she advised, 'Traffic no longer observed,' and the pilot continued his visual scan to the right.
Example Sentence 2
The tower reported traffic no longer observed on final approach, so we continued the landing sequence with visual lookout.