What minimum equipment is required for a flight from Kleberg Co Airport (area 7) to Corpus Christi Intl. Airport (area 3)?

• A. Two-way radio only
• B. Mode C transponder only
• C. Two-way radio and Mode C transponder with altitude reporting equipment
• D. DME and VOR receiver

Answer: (C)

Two-way radio communication and an altitude-encoding transponder are required when you’re operating in or into controlled airspace like Class B. The flight from Kleberg County to Corpus Christi International would involve entering or operating inside that airspace, so ATC needs to be able to contact you and you need to be identifiable with altitude information. Having both ensures you can communicate with ATC and that your aircraft’s position and altitude are visible on their radar.

Two-way radio alone would let you talk to ATC but provides no altitude data to the controller. A Mode C transponder with altitude reporting gives ATC the altitude information but doesn’t establish communication. DME and VOR are navigation aids and not the minimum required for this scenario.