DME is required above which flight level?

DME is required above which flight level?

• A. Below FL240
• B. At or above FL320
• C. Above FL240
• D. Only during night

Answer: (C)

The main idea is that higher-altitude jet routes and fixes often rely on distance information from a DME station to determine precise position along an airway. DME provides an exact distance to a ground station, which, combined with other navaids, lets pilots identify fixes and navigate accurately over long, high-speed legs. This requirement is applied above a certain altitude to ensure reliable navigation and separation on high-altitude routes. Below that level, the navigation system can often be satisfied with VOR alone or other methods, so DME isn’t mandatory. The option about night isn’t a factor for the rule, and the threshold isn’t as high as above FL320.

The main idea is that higher-altitude jet routes and fixes often rely on distance information from a DME station to determine precise position along an airway. DME provides an exact distance to a ground station, which, combined with other navaids, lets pilots identify fixes and navigate accurately over long, high-speed legs. This requirement is applied above a certain altitude to ensure reliable navigation and separation on high-altitude routes. Below that level, the navigation system can often be satisfied with VOR alone or other methods, so DME isn’t mandatory. The option about night isn’t a factor for the rule, and the threshold isn’t as high as above FL320.