Definition
On an electronic flight display, magenta-colored lines or symbols used to indicate predictive or trend information, most commonly the projected flight path or position of the aircraft a set number of seconds into the future based on current performance.
Plain English
The pinkish-purple lines on a glass cockpit display that show where the aircraft is going to be in a few seconds if nothing changes. They give the pilot a forward-looking picture of the airplane's path, not its current state.
Context Anchor
Seen on glass-cockpit displays when watching airspeed or altitude change during climbs, descents, acceleration, or deceleration.
Derivation
Magenta is a pinkish-purple color named after the 1859 Battle of Magenta in Italy, around the time the dye was discovered. Avionics designers chose magenta as a deliberately distinct color so pilots can instantly tell predictive information apart from current readings, which are usually shown in white or green.
Why Pilots Care
They give immediate visual warning of impending speed or altitude deviations so the pilot can correct early and maintain stable flight.
Analogy
They work like a short preview of where the pointer is going, not just where it is now.
Intuition Check
Do not assume these magenta lines are just decoration or the course line from a moving map. In this context, they show the near-future trend of airspeed or altitude on the flight display.
Example Sentence 1
During the climb, the pilot watched the magenta lines on the airspeed tape extend upward toward Vy and adjusted pitch to hold the target speed.
Example Sentence 2
As the pilot leveled off, the magenta line on the altimeter settled at the target altitude, confirming the climb had stopped.