If ATC advises you to use best forward speed can you go faster than 250 knots below 10,000 feet?

• A. Yes
• B. No, you can't break regulation
• C. Only with ATC clearance
• D. Only above 5,000 feet

Answer: (B)

The main idea here is a hard speed limit below 10,000 feet. In the United States, you must not fly faster than 250 knots indicated airspeed when you’re below 10,000 feet MSL. This limit is a regulatory requirement, not a suggestion.

If ATC says to use the best forward speed, that instruction guides you on how to manage spacing and sequencing, but it does not override the 250-knot ceiling. You should comply with the instruction up to that limit, and you can’t exceed 250 knots just because ATC asks you to go faster. If higher speed is truly needed, it would require a specific clearance with conditions that place you where the limit doesn’t apply (for example, higher altitude or different airspace rules).