What is the purpose of "readback" in ATC communications and which items should be read back by pilots?

• A. To confirm receipt of ATC instructions by an automatic acknowledgment.
• B. To replay ATC instructions to confirm accuracy; read back altitude, heading, squawk, and other critical items.
• C. To request permission to change frequency.
• D. To log the communication in the flight plan.

Answer: (B)

Readback is a safety check that makes sure both you and the controller are on the same page about what was issued. The key idea is to repeat back the parts of the clearance that directly affect your aircraft’s path and state, so any mishearing or misinterpretation is caught before you act. You should read back the altitude or flight level, the heading or route, the speed if a restriction was given, the transponder code (squawk), and any other critical items such as hold instructions, approach clearances, or specific constraints. This isn’t just an automatic acknowledgment; it’s repeating the exact numbers and instructions to verify accuracy. Frequency changes and logging the communication aren’t read back as part of the clearance, though you will acknowledge or request actions separately as needed.