Where should a DME antenna be installed for best reception?

Where should a DME antenna be installed for best reception?

• A. Right in the centerline in front of the wing
• B. Center of the belly
• C. Unobstructed line of sight
• D. On the tail

Answer: (C)

DME relies on microwave signals exchanged between the aircraft antenna and a ground station, so a clear, direct path is essential. Any obstruction from the airframe, wings, tail, or internal equipment can weaken or distort the signal, leading to poorer distance measurements or loss of lock. The best location is where the antenna has an unobstructed line of sight to the ground stations across the aircraft’s normal attitudes and flight regimes. That’s why, in practice, DME antennas are positioned where they can look out toward the horizon with minimal shielding from the fuselage, rather than in a spot that’s likely to be shadowed by wings or tail surfaces.

DME relies on microwave signals exchanged between the aircraft antenna and a ground station, so a clear, direct path is essential. Any obstruction from the airframe, wings, tail, or internal equipment can weaken or distort the signal, leading to poorer distance measurements or loss of lock. The best location is where the antenna has an unobstructed line of sight to the ground stations across the aircraft’s normal attitudes and flight regimes. That’s why, in practice, DME antennas are positioned where they can look out toward the horizon with minimal shielding from the fuselage, rather than in a spot that’s likely to be shadowed by wings or tail surfaces.