Under minimum prescribed separation, the preceding aircraft must be ___ for the separation to be applied using landmarks.

• A. airborne
• B. on the ground
• C. in the pattern
• D. in cruise

Answer: (A)

Using landmarks to apply minimum separation relies on knowing where the first aircraft is while it’s in flight, so you can measure the distance to the second aircraft relative to fixed ground references or fixes. The essential point is that the preceding aircraft must be airborne, because only in the air can those landmark references be used to establish and maintain the required separation. If the leading aircraft is on the ground, there isn’t an airborne position to reference, so landmark-based separation isn’t applicable. So, the correct completion is airborne. (Being in the pattern or in cruise would still be airborne, which satisfies the condition; being on the ground does not.)