"True Airspeed. What is it? How do you calculate? Why is it important?" - Mo S.
“True airspeed is important because performance charts in your Pilot Operating Handbook (POH) are based on true airspeed.
True airspeed is a calculated number depicting how fast the aircraft is moving through a still air mass. It is computed using indicated airspeed, pressure altitude, and temperature.
Remember that indicated airspeed drops off as we climb, due to lower air density at (higher) altitudes not having the same impact on the pitot tube.
By using an E6B flight computer, we can arrive at true airspeed.
Some airspeed indicators have a true airspeed ring around them that can be set for outside air temperature, pressure altitude, and allow you to read true airspeed off a scale on the ring.
Glass cockpit aircraft typically have what is called an air data computer, which processes the above information and displays it for you.
Ground speed is used to determine how long to a destination. True airspeed is used with the Pilot Operating Handbook to determine rates of fuel consumption over that period of time.”