A departing Cirrus SR22 is airborne. The earliest time you may clear a succeeding Piper Cherokee for takeoff from the same runway using minimum prescribed separation is ___.

• A. immediately after takeoff clearance
• B. when 3,000 feet exists between the two aircraft
• C. after 5,000 feet
• D. when the preceding has landed

Answer: (B)

Wake turbulence is the key factor here. When a plane has already taken off from a runway, the next aircraft that follows needs enough distance to fly out of the lead’s wake vortices. For two small aircraft departing in sequence on the same runway, the minimum separation you must have before authorizing the next takeoff is 3,000 feet. That spacing gives the trailing airplane enough room to lift off and climb without entering the lead’s turbulent wake, reducing the risk of loss of control or a sudden altitude change.

So, you may clear the succeeding Cherokee for takeoff once there are 3,000 feet of separation between the two aircraft. Waiting for the preceding to land isn’t required, and taking off immediately would expose the trailing aircraft to wake turbulence. Requiring 5,000 feet would be more separation than the minimum necessary.