Clear aircraft via routes consistent with the __________ stratum in which the operation is to be conducted.

• A. Altitude
• B. Temperature
• C. Wind
• D. Humidity

Answer: (A)

Airspace is organized into vertical layers called strata, and each stratum has its own routes and separation standards. When you clear an aircraft, you must route it so the path fits the altitude stratum in which the operation will be conducted. This alignment ensures the controller can apply the correct traffic separation, follow the established airways, and avoid conflicts with other aircraft operating in the same vertical band. If the route weren’t consistent with the designated altitude, you’d risk mismatches in traffic flows and airspace restrictions.

Temperature, wind, and humidity affect performance and weather, but they don’t define which routes or altitude layers are used for a clearance.