Calculation should include the following:
- Pressure altitude—the altitude indicated when the altimeter setting window (barometric scale) is adjusted to 29.92 "Hg (inches of Mercury).
- This is the altitude above the standard datum plane, which is a theoretical plane where air pressure (corrected to 15 °C) equals 29.92 "Hg.
- Pressure altitude is used to compute density altitude, true altitude, true airspeed (TAS), and other performance data.
PLT019