Definition
The estimated time at which a flight is expected to cross the boundary between two adjacent air traffic control facilities, used by ATC for traffic flow planning, coordination, and handoff between sectors or centers.
Plain English
The time a flight is expected to cross from one ATC facility's airspace into the next one's. Controllers use it to plan ahead and coordinate the handoff.
Context Anchor
Seen in air traffic control and flight-planning information where aircraft movement across airspace boundaries is being coordinated.
Derivation
‘Proposed’ means planned or estimated rather than confirmed. ‘Boundary crossing’ refers to passing from one controller's airspace into another's. So the term simply means the planned time the flight will move between airspaces.
Why Pilots Care
Correct PBCT timing supports smooth handoffs, prevents traffic conflicts, and keeps the flight on its filed route.
Intuition Check
“Proposed” does not mean the pilot is cleared to cross at that time. It means the time is being used for planning and may change.
Example Sentence 1
The center used the flight's PBCT to coordinate the handoff with the next facility before the aircraft reached the sector edge.
Example Sentence 2
ATC revised the PBCT after the pilot requested a direct routing to avoid weather.