What must a controller do if a pilot states their assigned altitude on initial contact?

When a pilot states their assigned altitude on initial contact, the controller must acknowledge this information and proceed with the clearance. This acknowledgment confirms to the pilot that the controller has received and understood their reported altitude, which is vital for maintaining proper communication and ensuring safe air traffic management.

If a controller acknowledges the altitude and provides further instructions, it signals to the pilot that they can continue adhering to their assigned altitude or await any necessary changes based on air traffic conditions. This approach fosters a smooth interaction where the pilot feels confident that their message has been received correctly.

Other options would imply unnecessary steps or complications in the communication process. Altering the altitude immediately is not appropriate unless there is a safety concern or regulation that necessitates such action. Requesting further confirmation or instructing the pilot to repeat could create confusion or delays, undermining the efficiency of air traffic control operations. Therefore, acknowledging the stated altitude and proceeding with the clearance is the most effective and streamlined response.