Garmin aera 796 Pilot's Guide - Page 179

Overview GPS Navigation Flight Planning Hazard Avoidance Additional Features Appendix G • 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. Appendices Index 190-01194-00 Rev. A Garmin aera 795/796 Pilot's Guide 165