If an enroute aircraft requests an altitude change that cannot be granted, what must the controller do?

• A. Deny the request
• B. Do nothing
• C. Enter the requested altitude into the flight plan or 4th line data entry, or coordinate with the next sector
• D. Change the aircraft's speed instead

Answer: (C)

When you can’t grant an altitude change, the important step is to preserve the pilot’s intent and keep everyone in the loop. Entering the requested altitude into the flight plan or the 4th line data entry records what the pilot asked for and what you’re unable to approve, so the flight plan remains accurate and the controller handoff knows what to expect. If needed, you also coordinate with the next sector to ensure the aircraft’s vertical profile is managed across boundaries, maintaining proper separation and a clear path forward for reattempts or alternatives. Ignoring the request or using speed changes alone doesn’t document the intent or keep the next controller informed, which can lead to confusion and potential conflicts.