How should multiple cruising altitudes be entered in block 7 of a flight plan?

When filling out block 7 of a flight plan, it's essential to understand the requirements for indicating altitude. The correct approach is to list only the first altitude. This practice helps air traffic control prioritize and organize flight data effectively. By indicating the initial altitude, it provides a clear and concise representation of the planned flight path, ensuring that there is no ambiguity about where the pilot intends to start flying at cruising altitude.

Air traffic control is primarily concerned with the departure altitude and initial climb path, which is why only the first altitude is necessary. This keeps the information straightforward and reduces the potential for confusion, particularly in scenarios where multiple cruising altitudes could complicate the communication process.

Other alternatives, such as listing all selected altitudes or providing a range, can lead to misunderstandings in flight operations and aren't standard procedures for flight plan submissions.