Primary Instrument:
* Air Speed Indicator (ASI): This is the most common instrument used to display the airplane's speed. It measures the dynamic pressure of the air flowing over the aircraft, which is directly related to speed. However, it only shows the indicated airspeed (IAS), which needs to be adjusted for various factors to get the true airspeed.
Other Important Systems and Instruments:
* Pitot Tube: This is a small tube that protrudes from the aircraft and measures the dynamic pressure of the air. This pressure is used to calculate the indicated airspeed.
* Static Port: This is a small hole in the aircraft that measures the static pressure of the air. This pressure is needed to correct for altitude and air density.
* GPS: While not specifically measuring speed, GPS provides a very accurate ground speed reading, which is the airplane's speed relative to the ground.
* Flight Management System (FMS): This sophisticated system combines data from multiple sources, including the ASI, GPS, and other sensors, to calculate and display the true airspeed (TAS), which is the actual speed of the aircraft relative to the air.
It's important to remember:
* The indicated airspeed (IAS) is not the actual speed of the aircraft.
* The true airspeed (TAS) is the actual speed of the aircraft relative to the air, and it is affected by altitude, air density, and wind conditions.
So, while the Air Speed Indicator is the primary instrument used to display the airplane's speed, it's just one part of a complex system that accurately determines the speed of an aircraft.
