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What does a Mode C transponder provide that Mode A does not?

Choices

  • ✓ Pressure-altitude reportingcorrect

    Mode C adds altitude reporting to the assigned code.

  • A data link with unique aircraft addressing

    That capability belongs to Mode S, not Mode C.

  • Two-way voice communication

    A transponder does not provide voice communication.

  • GPS position to satellites

    Broadcasting GPS position is an ADS-B function, not Mode C.

Why

Mode A reports only the assigned code, while Mode C adds pressure-altitude reporting; Mode S further adds a data link and unique addressing.

FAA source: AIM 4-1-20browse the reference library →

This is taught in Avionics: Glass Cockpit, Transponder and GPS — study the lessons free, then practice with grading and mastery tracking.

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Original study question written for this course — representative of FAA knowledge-test topics, not an actual current FAA exam question. Reviewed by a panel of three CFIs + AI review.

What does a Mode C transponder provide that Mode A does not? · PPL Free Ground School