Garmin aera 796 Pilot's Manual page 221

• Indicated Altitude—required entry for density altitude/true airspeed calculation.
Enter the aircraft's altimeter reading.
• Baro Pressure—when the unit is receiving XM weather information, the field
automatically updates to the barometric pressure of the nearest METAR. If XM
weather information is not available you need to enter the current barometric
pressure.
• Calibrated Airspeed— required entry for density altitude/true airspeed
calculation. Enter the aircraft's airspeed indicator value.
• Total Air Temp— required entry for density altitude/true airspeed calculation.
Total Air Temperature (TAT) is the temperature of the air including the heating
effect caused by speed. The temperature reading on a standard outside air
temperature gauge found on most piston aircraft is TAT.
• Heading— required entry for winds aloft calculation. Use heading from the
aircraft's heading indicator or directional gyro.
• True Airspeed— (calculated or user-entered figure) determined from entry of
calibrated airspeed, barometric pressure, and total air temperature. This can also
be entered directly for winds aloft calculations.
• Tail Wind— (calculated figure) determined from entry of heading and true
airspeed.
• Wind From—(calculated figure) determined from entry of heading and true
airspeed.
• Wind Speed—(calculated figure) determined from entry of heading and true
airspeed.
• Density Altitude— (calculated figure) determined from entry of indicated
altitude, barometric pressure and total air temperature.
190-01194-00 Rev. C Garmin aera 795/796 Pilot's Guide
Appendix G
205