What does a transponder with Mode C provide to ATC?

What does a transponder with Mode C provide to ATC?

• A. A device for in-flight entertainment.
• B. A mechanism to measure turbulence.
• C. A radio frequency booster.
• D. Transponders help ATC identify aircraft, including altitude and flight data.

Answer: (D)

Mode C is about altitude information. A transponder responds to radar interrogations from ATC, and when Mode C is used, the reply includes the aircraft’s altitude in a coded form. This lets ATC identify which aircraft is on the radar screen and know how high it is, which is essential for maintaining safe vertical separation. It’s not designed for in-flight entertainment, turbulence measurement, or simply boosting radio power. Some transponders can also send additional flight data with newer systems, but the main benefit of Mode C is providing altitude to ATC.

Mode C is about altitude information. A transponder responds to radar interrogations from ATC, and when Mode C is used, the reply includes the aircraft’s altitude in a coded form. This lets ATC identify which aircraft is on the radar screen and know how high it is, which is essential for maintaining safe vertical separation. It’s not designed for in-flight entertainment, turbulence measurement, or simply boosting radio power. Some transponders can also send additional flight data with newer systems, but the main benefit of Mode C is providing altitude to ATC.