Definition
Vertical or horizontal moving-scale indicators on an electronic flight display that show values such as airspeed, altitude, and vertical speed. The numbers scroll past a fixed reference pointer, and the current value appears in a readout window at the pointer.
Plain English
Strips of numbers on the glass cockpit screen that slide up or down as the airplane speeds up, slows down, climbs, or descends. The number lined up with the pointer is your current value.
Context Anchor
Seen on electronic flight displays during instrument flying, especially when cross-checking attitude with airspeed, altitude, and other flight information.
Derivation
Called 'tape' because the moving scale resembles a strip of measuring tape sliding past a fixed mark, with only a small portion visible at any moment.
Why Pilots Care
Tape displays read differently from round dials. Instead of seeing a needle sweep around a clock face, the pilot watches numbers scroll past a fixed pointer. The trend is shown by direction and speed of motion rather than needle position, which takes practice to interpret quickly during instrument flight.
Analogy
It is like watching numbers move past a fixed pointer on a ruler. The pointer shows the current value, and the nearby numbers show where the value is going.
Intuition Check
Tape does not mean adhesive tape or recording tape here. It means a strip-shaped scale on a flight display.
Example Sentence 1
On the PFD, the airspeed tape display showed 110 knots accelerating toward 120 as the pilot advanced the throttle.
Example Sentence 2
A quick glance at the altitude tape display showed a 50-foot deviation before it became a larger problem.