Overview
The Airspeed Indicator (ASI) is a differential pressure instrument used specifically to measure dynamic pressure. This measurement is displayed as an indicated airspeed in units of either knots or miles per hour.
Examples
Memory Aids
| Speed | Definition | Marking |
|---|---|---|
| Caution Range | Smooth Air Operations Only | Yellow Arc |
| Normal Range | Full Operations Allowed | Green Arc |
| Flaps Range | Flaps May Be Extended | White Arc |
| VNE | Never Exceed Speed | Red Line |
| VNO | Maximum Structural Cruise Speed | Bottom of Yellow Arc |
| VFE | Maximum Flap Extended Speed | Top of White Arc |
| VS1 | Stall Speed (Specified Configuration) | Bottom of Green Arc |
| VS0 | Stall Speed (Landing Configuration) | Bottom of White Arc |