In a non-radar environment, large aircraft departing behind heavy aircraft should be separated by ______ miles or ______ minutes.

• A. 4 miles or 5 miles or 2 minutes
• B. 3 miles or 6 miles or 1 minute
• C. 6 miles or 7 miles or 3 minutes
• D. 8 miles or 9 miles or 4 minutes

Answer: (A)

In non-radar operations, separation is kept using either a distance in miles or a time interval in minutes, since there’s no radar to continuously monitor exact spacing. For a large aircraft following a heavy aircraft, the safe rule is to maintain about 4 miles of separation or a 2-minute separation. This safeguards against wake turbulence and gives the trailing aircraft enough time to establish its own climb and avoid disturbed air from the lead.

The other options propose different numbers, but they don’t reflect the standard minimum for this scenario. They would either be too small to reliably account for wake effects and performance variability, or they exceed what’s required and reduce efficiency. So the best, standard separation is 4 miles or 2 minutes.