What minimum radio equipment is required for VFR operation within Class B airspace?

What minimum radio equipment is required for VFR operation within Class B airspace?

• A. Encoding altimeter only
• B. Two way radio and encoding altimeter only
• C. Two way radio, 4096 code transponder, encoding altimeter
• D. Two way radio and transponder Mode S only

Answer: (C)

The key idea is that Class B operations require both two-way communication with ATC and radar identification with altitude. For VFR in Class B, you must be able to talk to ATC and you must provide altitude information to radar. A two-way radio lets you obtain and maintain ATC clearance, and an altitude-encoding transponder (Mode C) lets ATC see your exact altitude on their radar. The “4096 code” part refers to having a discrete transponder code (Mode A) in addition to altitude reporting, which helps ATC identify your aircraft while it tracks you in busy airspace. So the minimum is two-way radio plus a transponder that encodes altitude. The other options lack one of those essential pieces: either no transponder, or no altitude encoding, or rely on Mode S alone (which isn’t the standard minimum specified for Class B).

The key idea is that Class B operations require both two-way communication with ATC and radar identification with altitude. For VFR in Class B, you must be able to talk to ATC and you must provide altitude information to radar. A two-way radio lets you obtain and maintain ATC clearance, and an altitude-encoding transponder (Mode C) lets ATC see your exact altitude on their radar. The “4096 code” part refers to having a discrete transponder code (Mode A) in addition to altitude reporting, which helps ATC identify your aircraft while it tracks you in busy airspace.

So the minimum is two-way radio plus a transponder that encodes altitude. The other options lack one of those essential pieces: either no transponder, or no altitude encoding, or rely on Mode S alone (which isn’t the standard minimum specified for Class B).