(案例分析)某日某机组接收管制员指令在某点等待，管制员并未告知机组左或右等待，飞机此时正好正切这一点左等待2转弯改出位置，机组随即加入左等待飞三边航迹，请问机组加入等待程序是否正确？简述原因（cases analysis）On a certain day, a crew received a command from the controller to hold over a certain point, and the controller did not inform the crew that it was a left or right holding. At this moment, the aircraft was just tangent to the Exit position of the 2nd turn of the left holding over this point. And the crew then immediately joined the left holding to fly the downwind track. Was the way correct that the crew joined the holding procedure? Brief the reasons.