Which device computes true airspeed and Mach number?

Which device computes true airspeed and Mach number?

• A. Air Data Computer
• B. Inertial Navigation System
• C. Global Positioning System
• D. Traffic Collision Avoidance System

Answer: (A)

Calculating true airspeed and Mach number relies on air data that describe the conditions of the air around the aircraft and how fast you're moving through it. The Air Data Computer takes input from the pitot tube (dynamic pressure) and the static port (static pressure) along with temperature information. From dynamic pressure you get indicated airspeed, and with temperature and pressure corrections the computer computes true airspeed, which is your speed through the air adjusted for altitude and nonstandard temperature. Mach number is derived by dividing the true airspeed by the local speed of sound, and the speed of sound changes with air temperature, so temperature data are essential for Mach. This unit aggregates the raw measurements and delivers clean air data to the flight instruments. Other systems have different roles: inertial navigation uses accelerations to track position and velocity, GPS provides position and groundspeed, and TCAS focuses on resolving traffic conflicts. Only the Air Data Computer combines pitot-static data with temperature to produce TAS and Mach.

Calculating true airspeed and Mach number relies on air data that describe the conditions of the air around the aircraft and how fast you're moving through it. The Air Data Computer takes input from the pitot tube (dynamic pressure) and the static port (static pressure) along with temperature information. From dynamic pressure you get indicated airspeed, and with temperature and pressure corrections the computer computes true airspeed, which is your speed through the air adjusted for altitude and nonstandard temperature. Mach number is derived by dividing the true airspeed by the local speed of sound, and the speed of sound changes with air temperature, so temperature data are essential for Mach. This unit aggregates the raw measurements and delivers clean air data to the flight instruments. Other systems have different roles: inertial navigation uses accelerations to track position and velocity, GPS provides position and groundspeed, and TCAS focuses on resolving traffic conflicts. Only the Air Data Computer combines pitot-static data with temperature to produce TAS and Mach.