(downrange travel) of the aircraft in an attempt to either force a dangerous overshoot, on the part of the defender, or prevent a dangerous overshoot on the attacker's part. The defender's goal is to stay out of phase with the attacker, trying to prevent a guns solution, while the attacker tries to get in phase with the defender. The advantage usually goes to the more maneuverable aircraft. There are two types of scissor maneuvers, called flat scissors and rolling scissors. Flat scissors Flat scissors, also called horizontal scissors, usually occur after a low-speed overshoot in a horizontal direction. The defender reverses the turn, attempting to force the attacker to fly out in front and to spoil aim. The attacker then reverses, trying to remain behind the defender, and the two aircraft begin a weaving flight pattern. Rolling scissors Rolling scissors, also called vertical scissors, tend to happen after a high-speed overshoot from above. The defender reverses into a vertical climb and into a barrel roll over the top, forcing the attacker to attempt to follow. The advantage lies in the aircraft that can pull its nose through the top or bottom of the turn faster. In battles with aircraft that have a thrust-to-weight ratio of less than one the aircraft will quickly lose altitude, and crashing into the ground becomes a possibility. According to author Mike Spick, "Disengagement from a vertical rolling scissors is best made with a split-s and a lot of hope." Guns defense Guns defense maneuvering, or "guns-D", is the last resort for a defender that fails to outmaneuver the attacker. Guns-D is a series of random changes in the defenders flight path, intended to spoil the attacker's aim by presenting a constantly shifting target, and, hopefully, to maneuver out of the bullet stream (hose). It consists of arbitrary speed changes, yaws, skids, slips, pitch-ups, and rolls, and is often referred to as "jinking". Because the attacker must aim ahead of the opponent, the primary goal in guns-D is to disorient the attacker's aim by keeping the nose pointed in a different direction than the velocity vector (the direction of travel), and is very effective at preventing the attacker from achieving a suitable guns solution. However, guns-D maneuvering still leaves the defender susceptible to stray bullets and "lucky shot" hits, and does little to improve the relative positional situation. Thus, it is only employed as a last-ditch