Which statement about Class A airspace is true?

• A. Class A is from surface to 12,000 ft MSL.
• B. Class A airspace extends from 18,000 to 60,000 ft MSL and IFR clearance is required.
• C. Class A is only for VFR operations.
• D. Class A requires no transponder.

Answer: (B)

Class A airspace is high-altitude controlled airspace where IFR flight rules apply to all operations. It begins at 18,000 feet MSL and extends up to and including FL600 (60,000 feet). Entry requires an explicit ATC clearance, and you must be in two-way radio communication with ATC. VFR flight is not permitted in Class A. A functioning transponder with altitude reporting is required so ATC can identify and separate traffic.

That’s why the statement describing 18,000 to 60,000 feet MSL with required IFR clearance is the accurate one. The other options misstate the lower altitude boundary, suggest VFR use, or imply no transponder is needed, which aren’t true for Class A.