As soon as you started practicing the flight maneuvers for the private pilot practical test, you learned about clearing turns. Usually, a clearing turn involves a 90-degree turn to the left followed by a 90-degree turn to the right so that you roll out on the same heading on which you started -- at least you hope.
There’s no single definition of what constitutes a clearing turn, and some instructors prefer a 180-degree, 360-degree or some other type of clearing turn. The FAA doesn’t really care what type of clearing turn you perform, as long as you do something. According to the Private Pilot Practical Test Standards, “It is vitally important that the applicant uses proper and effective scanning techniques to clear the area before performing maneuvers.” The PTS goes on to state, “Ineffective performance in these areas will be disqualifying.”
That’s certainly one reason to perform clearing turns immediately before you start each maneuver, but the real reason is safety.
Still, some pilots are confused about why you’d want to perform the back-to-back 90-degree turns, rationalizing that it leaves a section of the sky unobserved. But think about it: You should be able to see out the right and left windows without turning, and a single 90-degree turn lets you see behind you; think of it as looking over your shoulder.
Also, it’s a good practice to start all your clearing turns to the left. Why? Overtaking aircraft that are behind you are supposed to pass on your right side. If you blindly enter a turn to the right, you may cut off an airplane trying to pass on that side.