“Z-1 TO DOG 10. Hypo 28, high. 217 degrees. Target six heavy bombers. Acknowledge.” Dog 10, the leader of a dozen pursuit planes on patrol guard at 9,000 feet, acknowledged the radio message and opened his throttle, pointing his plane in the direction he had been instructed to fly. The rest of the squadron fell in behind. On his map the leader located Hypo 28, the area in which the bombers were reported. It was 60 miles away. Soon another radio message came in and Dog 10 changed course to the left. The interception service on the ground was tracking the invading bombers as they flew inland and each time the bombers changed course, new instructions went out to the pursuits; guiding them closer to their target. Finally one of the pilots located the hostile planes and he spoke into his microphone, alerting the leader and the rest of his squadron. “Dog 21. Target 45 degrees right, below.” The leader rapidly estimated the best method of attack, gave his orders over the radio, and the dozen pursuit planes tilted downward toward the bombers. There was only a fraction of a second in which they could fire as they hurtled past, then they reformed and climbed for another stab at the bombers. Pursuit planes are the best defense against enemy aircraft but the pursuits have to close in on the enemy before they can knock him out. Helping them to do so is the job of the interception service. Scores of observers spotted over the countryside telephone in when bombers pass overhead and the interception service plots the path of the bombers from this information, then radios the pursuit leader the course to fly to intercept them. Radio orders are in simple code. This week the squadron leader’s name may be Dog 10; next week he may be called Apple Five or Cat Six. Tracking down their targets in this way is one of the training exercises of pursuit groups such as those based at March Field, Calif. Gunnery is next in importance and day after day the pilots fire at towed sleeve targets, small panels setup on the ground and shadows. Shadow shooting is one of the most realistic of all exercises and to do this one airplane flies over the water in such a way that its shadow is seen on the waves below. The other planes use this shadow as the target, diving and firing and observing the splash of their bullets while the speeding shadow turns and dodges. Accuracy is what counts. In shooting at a panel target on the ground, simply hitting the panel isn’t enough. The pilot must pour shots into a small bullseye, just as in actual air battle he must hit vital parts of the enemy plane instead of merely shooting holes in the wings. The pursuit pilot is literally the superman of the air force. Pilot, navigator, radio operator, gunner - he must be his own four-man crew. Acrobatics and tight formation flying are the rudiments of his training, but they aren't as simple as they used to be because the high spéeds of today’s pursuit planes are a complicating factor. A pilot uses all the speed he has to catch up with another plane, then he has to slow down to fight. The pilot who can make the tightest turns is most often the victor, so he slows down a bit in order to turn sharper. He still maneuvers so fast that he blacks out in some turns, though he can train himself to reduce the interval of this unconsciousness both by practice and by tightening his stomach muscles as he goes into the turn, pushing his chin down tightly on his chest and shouting at the top of his voice. Add to all this the fact that most air fighting today is at a minimum of 15,000 feet and much of it at 30,000 feet and higher where the lack of air slows down all his reactions, and you begin to see that a pursuit pilot has to keep himself in tip-top physical condition. Calisthenics and handball are as important parts of his daily routine as is flight training. In single combat a pilot must be a rugged individualist, yet half his fighting is done in formation and when he is part of a formation he has to follow the leader without daring to use his own initiative. In a formation fight he doesn’t even aim at the target and he fires his guns only when told to do so. The leader of the flight aims his own plane at the target and gives a radio signal for the others to fire. The leader knows that the other planes, hugging his own wings, are pointed in the same direction that he is, and that their bullets will be as effective as his own. High speed, too, has affected the science of gunnery. It is almost invariably true that a pilot will never hit a target that he catches squarely in the center of his electric gunsight. Instead of aiming his plane like a rifle he has to point it like a shotgun, firing far enough in front of the moving target to give his bullets a chance to arrive at a certain spot simultaneously with the target. There are no mechanical adjustments that can be made to the gunsight; marksmanship depends on the pilot’s skill alone. That's the reason every pursuit plane base is equipped with its own skeet field. At least once a week the pilots spend an afternoon at skeet shooting. This gives them excellent experience in shooting at flying targets. Flying at his target, the pilot is taught to get in as close as he dares before firing. Fire from 100 yards is far more effective than from three or four hundred yards away. He has to follow through while firing so that his bullets will continue to pound the target, just as he has to follow through while firing at a clay pigeon on the skeet range. By now he has to be on his toes to avoid a collision, yet he dare not pull out in any direction he pleases. To do so might expose himself to return fire, so he has to turn toward the target’s blind spot to avoid being shot down while he is escaping. The battle for air supremacy is a see-saw. For a while the pursuit planes had an edge over the relatively unprotected bombers, then the bombers added heavier defensive guns and ganged up to keep the pursuits away. The answer to that was to increase the fire power of the pursuits to allow the fighter pilots to get in killing blows before the bombers could blast them out of the sky. A pursuit plane used to be armed with a couple of .30-caliber machine guns. Now a pursuit plane is apt to have eight or ten guns mounted in its fuselage and wings, including 20 and 37 mm. cannon as well as .30 and .50-caliber machine guns. The result is that when the pilot presses the master firing trigger under his thumb an actual hail of bullets pours out in front of him. Each fifth bullet is a tracer. Fully loaded, his plane holds several thousand rounds of belt- and clip-fed ammunition. This is enough for only a few seconds of firing, but since the pilot is on his target for only split seconds at a time, the ammunition that he carries is enough for a long battle.