What is the proper phraseology for confirming altitude information for an aircraft in level flight?

The correct phraseology for confirming altitude information for an aircraft in level flight is to use "Verify at (altitude/flight level)." This phraseology is standardized and is specifically designed to instruct pilots to ensure that their altitude reading is accurate. By using the term "verify," it prompts the crew to cross-check their instruments against the reported altitude, ensuring safety and proper communication in the air traffic environment.

Using "verify" in this context is particularly effective as it implies a confirmation process that is essential in maintaining situational awareness for both controllers and pilots. It signifies that the altitude in question should be checked and confirms to air traffic control that the aircraft is at that altitude. This is crucial for maintaining safe separation standards and ensuring that all parties have synchronized information.

The other phraseology options do not align with the recognized terminology used in air traffic control communications. Therefore, aligning with the correct phraseology not only promotes clarity and understanding but also adheres to the established standards of communication in aviation, which is vital for the safe operation of aircraft in controlled airspace.