Definition
A computer-generated visual depiction, displayed on a synthetic vision system, of the intended flight path shown as a series of boxes, rectangles, or a tunnel-like corridor in the sky that the pilot flies through to follow the programmed route, course, or approach.
Plain English
A picture on the cockpit screen that shows your planned flight path as a row of frames or a tunnel in the sky. You fly through them, and you know you're on track.
Context Anchor
Seen on electronic flight displays that use synthetic vision, especially when flying by instruments or when outside visibility is limited.
Derivation
Synthetic' comes from the Greek 'synthetos' meaning 'put together' -- here it means computer-generated rather than a real outside view. 'Highway' is borrowed from the road sense: a clearly marked path you follow. Together: a computer-drawn road in the sky.
Why Pilots Care
It turns abstract numbers (course, altitude, glide path) into a single intuitive picture, reducing workload and helping the pilot stay on path in low visibility or unfamiliar terrain.
Analogy
It is like a marked lane drawn ahead of you, except the lane is shown on the cockpit screen and represents the path through the air.
Grounding Statement
The display turns a planned route into something the pilot can see and aim to follow on the screen.
Intuition Check
“Synthetic” does not mean fake or unreliable here; it means computer-generated. “Highway” does not mean a road; it means a visual path through the air.
Example Sentence 1
On the ILS approach, the pilot kept the aircraft centered in the synthetic highway displayed on the primary flight display.
Example Sentence 2
With the synthetic highway visible on the display, the flight continued smoothly through the clouds toward the airport.