The following is a common ATC command:
“OK-VLK make left closed traffic report midfield downwind”
Many European pilots, when hearing this VFR phraseology, have asked me, “what is closed traffic?”.
Closed traffic is the term commonly used in North America for the VFR traffic pattern. Left and right indicate the direction of turns. Left closed traffic consists of a left 90 degree turn from the upwind leg to the crosswind leg. From there follows a 90 degree turn to downwind, 90 degrees to base, and 90 degrees to final - all left turns. Left is the standard direction of closed traffic turns because of the visibility advantage it gives from sitting in the left seat.
While many airports use the phrase closed traffic, others use circuit: “Left circuit approved, report base”
closed traffic (remember, the verb “make” is used with closed traffic”)
Here are some correct responses to the ATC command:
“Roger, will make left closed and report the downwind”
“Roger, will make left closed traffic report downwind”
“Roger, making left closed traffic will report downwind”