Describe the components and function of the air data system that provides airspeed, altitude, and vertical speed.

Describe the components and function of the air data system that provides airspeed, altitude, and vertical speed.

• A. Pitot tube provides ambient pressure; static ports measure dynamic pressure; the Air Data Computer processes to compute velocity, altitude, and vertical speed.
• B. Pitot tube provides dynamic pressure, static ports provide ambient/static pressure; the Air Data Computer processes to compute airspeed, altitude, vertical speed.
• C. Static ports provide dynamic pressure; pitot tube ambient pressure; the ADC processes to compute velocity.
• D. The Air Data Computer uses total pressure to compute fuel flow.

Answer: (B)

The topic being tested is how the air data system uses pressure measurements to derive speed, altitude, and vertical velocity. The Pitot tube supplies dynamic (ram) pressure, while the static ports provide ambient static pressure. The Air Data Computer takes Pt and Ps and, after applying corrections for instrument error, position, and compressibility, derives airspeed from the dynamic pressure (Pt minus Ps) and altitude from the static pressure relative to the standard atmosphere. Vertical speed comes from how quickly the static pressure is changing over time, which the ADC converts into a rate of altitude change. This combination—dynamic pressure for airspeed and static pressure for altitude and vertical speed—is why the correct description assigns dynamic pressure to the Pitot tube and ambient/static pressure to the static ports, with the ADC doing the computations.

The topic being tested is how the air data system uses pressure measurements to derive speed, altitude, and vertical velocity. The Pitot tube supplies dynamic (ram) pressure, while the static ports provide ambient static pressure. The Air Data Computer takes Pt and Ps and, after applying corrections for instrument error, position, and compressibility, derives airspeed from the dynamic pressure (Pt minus Ps) and altitude from the static pressure relative to the standard atmosphere. Vertical speed comes from how quickly the static pressure is changing over time, which the ADC converts into a rate of altitude change. This combination—dynamic pressure for airspeed and static pressure for altitude and vertical speed—is why the correct description assigns dynamic pressure to the Pitot tube and ambient/static pressure to the static ports, with the ADC doing the computations.