When do you find the DME antenna on the aircraft, and why?

When do you find the DME antenna on the aircraft, and why?

• A. On the bottom of the fuselage where it isn't blocked by the wings
• B. On the top of the vertical stabilizer
• C. Inside the cockpit ceiling
• D. Behind the nose radome

Answer: (A)

DME relies on line-of-sight UHF signals between the aircraft and ground DME stations. To get a reliable link, the antenna needs an unobstructed view toward the ground, away from the aircraft’s structure. Placing the antenna on the bottom of the fuselage keeps it clear of the wings and most of the airframe, providing a good transmission path and reception with ground stations. Locations like the top of the vertical stabilizer, inside the cockpit ceiling, or behind the nose radome would be hindered by the airframe or interior components and wouldn’t offer the same clear, unobstructed path, degrading performance.

DME relies on line-of-sight UHF signals between the aircraft and ground DME stations. To get a reliable link, the antenna needs an unobstructed view toward the ground, away from the aircraft’s structure. Placing the antenna on the bottom of the fuselage keeps it clear of the wings and most of the airframe, providing a good transmission path and reception with ground stations.

Locations like the top of the vertical stabilizer, inside the cockpit ceiling, or behind the nose radome would be hindered by the airframe or interior components and wouldn’t offer the same clear, unobstructed path, degrading performance.