Definition
A vertical bar displayed alongside the altitude tape on a primary flight display (PFD) that shows the predicted altitude the aircraft will reach in the next six seconds if the current vertical speed is maintained. The tape extends upward from the current altitude when climbing and downward when descending, and disappears when vertical speed is near zero.
Plain English
A small bar next to the altitude readout on a glass cockpit screen that shows where your altitude will be six seconds from now if you keep climbing or descending at the same rate.
Context Anchor
Seen on electronic primary flight displays during instrument flying, especially while holding altitude, climbing, descending, or leveling off.
Derivation
Trend means the direction something is heading. Tape refers to the moving vertical strip used on glass displays to show altitude (it scrolls past a fixed pointer like a tape measure). Together: a short visual strip showing the direction altitude is trending.
Why Pilots Care
Gives immediate visual warning of any unintended climb or descent so the pilot can correct pitch before the deviation grows large.
Intuition Check
Do not read “tape” as a physical strip of material. Here it means a vertical display strip on the instrument screen. Do not read “trend” as just past behavior. Here it is a near-term indication of where the altitude is going if nothing changes.
Example Sentence 1
As the altitude trend tape touched 5,000 feet, the pilot began reducing pitch to level off at the assigned altitude.
Example Sentence 2
With the autopilot engaged, the pilot watched the altitude trend tape stay flat during level cruise.