How must a pilot report an altitude of 10,500 feet to Air Traffic Control?

Reporting an altitude of 10,500 feet to Air Traffic Control is done using a specific format that promotes clarity and avoids confusion. The correct format is "Ten thousand five," which clearly communicates the altitude as 10,500 feet. By articulating it this way, the pilot ensures that each segment of the altitude is distinctly understood, avoiding any ambiguity.

In air traffic communication, it is crucial to avoid using decimals, as they can lead to misunderstanding. Using "ten point five thousand" incorporates a decimal that is not standard in altitude reporting. Similarly, "one zero five hundred" is unnecessarily complex and could potentially confuse the intended message. The option "ten thousand" alone only conveys part of the altitude and does not include the additional 500 feet, leading to incomplete information.

Thus, in air traffic operations, using "ten thousand five" provides a clear, concise, and accurate representation of the altitude, ensuring safe and efficient communication among pilots and air traffic controllers.