 Wing stall would also occur on the 707 with over-rotation so the leading-edge flaps were added to prevent stalling even with the tail dragging on the runway.The initial standard model was the 707-120 with JT3C turbojet engines.Qantas ordered a shorter-bodied version called the 707-138, which was a -120 with six fuselage frames removed, three in front of the wings, and three aft.