Definition
An ATC advisory phrase used during radar vectoring to an instrument approach, warning the pilot that the controller intends to vector the aircraft through the final approach course rather than turn it directly onto final. The through-course vector creates the time and distance needed to space this aircraft behind preceding traffic before turning it back to intercept the final approach course inbound.
Plain English
ATC is telling you they will vector you straight across the final approach course on purpose, not turn you onto it yet. They are doing this to leave a gap between you and the aircraft ahead. They will turn you back onto final once the spacing is right.
Context Anchor
Heard during instrument approaches when ATC is guiding aircraft by radar toward the final approach course.
Derivation
Vector comes from a Latin word meaning “carrier” or “one who carries.” In aviation, a radar vector is a heading assigned by ATC to carry the aircraft along a desired path. Final here means the final approach course, the line the aircraft will eventually follow inbound toward the runway or approach fix.
Why Pilots Care
Prevents wake-turbulence encounters and runway conflicts by guaranteeing proper spacing before final intercept.
Grounding Statement
Picture ATC briefly sending you past the inbound course, then turning you back when there is enough room in the traffic sequence.
Intuition Check
Do not assume “across final” means ATC forgot to turn you. In this phrase, crossing final is intentional, and “spacing” means ATC is managing distance between aircraft.
Example Sentence 1
Approach told us, 'Expect vectors across final for spacing,' so we held our heading and watched the localizer needle swing through the center.
Example Sentence 2
Because of a heavy jet on the ILS ahead, we received vectors across final for spacing before being turned to intercept.