An observer on the left and the remote pilot on the right, with the drone flying between them and a crewed aircraft approaching overhead. The observer calls: Traffic, hold. The pilot acknowledges: Copy, hold. The pilot acts and the drone brakes and holds position. The pilot confirms: Holding. A strip below lights Call, Acknowledge, Act and Confirm in turn, and an arrow closes the loop back to Call. In the missed acknowledgement version the pilot does not reply, the Acknowledge step shows a question mark, and the observer repeats the call more assertively before the loop continues. The drone has flown further by the time it holds.
