Although the primary danger pilots faced at first was from enemy (and friendly) ground fire, the need to prevent the enemy from carrying out reconnaissance became just as important as carrying out one’s own reconnaissance after a few weeks of war. As a result, the days of opposing pilots waving at each other in the air came to a quick end, as both sides resorted to a variety of weapons (e.g., bricks, large steel darts, grenades, pistols, rifles, and even grappling hooks) in an effort to drive the enemy from the skies. On 25 August 1914 pilots and observers in Royal Flying Corps No. 2 Squadron armed themselves with rifles and pistols. Within three days the British had forced three German Taubes to land. Although Germans would achieve similar successes of their own, the odds of hitting a moving target with a rifle or pistol were extremely small. Of all the weapons available, the most practical one was the machine gun.
The idea of firing a machine gun from an airplane actually predated the war. Early aircraft, however, lacked the power to carry a water-cooled machine gun, a pilot, and an observer. By 1912, however, technology was beginning to change as lighter-weight machine guns became available. On 7 and 8 June 1912 Captain Charles De- Forest Chandler of the U.S. Army Signal Corps fired a new aircooled machine gun, designed by Colonel Issac Newton Lewis, from the air in his Wright Type B airplane, placing 14 of 45 rounds into a 6-ft-tall, 18-in.-wide target from an altitude of 500 ft. Although the U.S. War Department failed to appreciate the significance of the demonstration, because it continued to see the airplane’s role as providing the eyes of the army, other European powers took notice. Well before the outbreak of the war, aircraft designers had recognized that the most practical method of firing a machine gun from an airplane would be to fire through the arc of the propeller, thereby allowing the pilot to use the airplane to aim the gun. German de signer Franz Schneider and French designer Raymond Saulnier had both independently developed an interrupter gear prior to 1914, but like the American War Department, the German and French General Staffs did not see any role for aircraft other than reconnaissance. In addition, the French War Ministry failed to adopt Saulnier’s design because the added weight of the water-cooled Hotchkiss gun—the French stubbornly refused to consider the aircooled Lewis gun—adversely affected aircraft performance.
As mentioned earlier, the need to prevent enemy reconnaissance aircraft from conducting their missions would quickly lead to the incorporation of the machine gun on aircraft by the end of 1914. Pusher aircraft, which had the propeller in the rear, had an initial advantage in that the machine gun could be placed in the nose and used to fire forward. On 5 October, for example, French Corporal Louis Quénault downed a German Aviatik while firing a Hotchkiss gun from the observer’s seat in a Voisin III pusher piloted by Sergeant Joseph Frantz. The British would introduce a similarly designed pusher, the Vickers F.B.5 Gunbus, in February 1915. Although pusher aircraft allowed observers to fire forward, they left the rear of the airplane vulnerable to attack and they were not as fast or maneuverable as tractor-driven aircraft (propeller in the front). It was for these reasons that the Germans opted for tractordriven aircraft and began installing their ring-mounted Parabellum gun in the observer’s seat. This offered a greater range of fire and the Parabellum’s drum had twice the capacity of the Lewis gun and four times the capacity of the Hotchkiss. The German ace, Oswald Boelcke, would get his first kill in such an aircraft. A few enterprising pilots mounted a Lewis gun on the top wing of their aircraft in order to fire over the arc of the propeller, but this presented its own hazards, as British pilot Louis Strange discovered on 10 May 1915 when his Martinsyde Scout turned upside down while he was attempting to change the drum on his Lewis gun, which was mounted on his upper wing. Strange somehow managed to hang on while the plane plummeted from 9,000 ft down to 1,500 ft before he was able to get back into the cockpit and right his plane.
As indicated earlier, the techniques improvised for using machine guns had their limitations, but this was soon to change. In March 1915 Roland Garros, a French pilot who had obtained fame for crossing the Mediterranean prior to the war, had been sent from the front to work with Saulnier in trying to perfect the process of firing through the propeller’s arc. Because the Hotchkiss gun was notorious for firing irregularly, Saulnier’s interrupter gear could not guarantee that a bullet would not strike the wooden propeller. After many experiments, Garros and Saulnier affixed wedge-shaped metal deflectors on the propeller and found that on average five in six shots passed through the propeller with the wedges deflecting the other. Although this presented some danger in that a deflected bullet could damage the engine or strike the pilot, Garros was undaunted and returned to the front in late March with a Hotchkiss gun affixed to his Morane-Saulnier monoplane. Beginning on 1 April 1915, Garros shot down five German planes in less than 3 weeks. On 18 April, however, he was forced down by ground fire behind enemy lines. Able to examine Garros’s plane, the Germans had the propeller at the Fokker factory within 24 hours.
After inspecting Garros’s plane, Dutch aircraft designer Anthony Fokker, who had begun aircraft construction in Germany just prior to the war, determined that the deflector shields provided only a partial solution. In any event, he had already been experimenting with Franz Schneider’s prewar interrupter design, and by late Spring 1915 had perfected it by synchronizing the interrupter gear with the camshaft of his new Fokker E.I monoplane, the Eindecker. In this way the interrupter gear could be timed to prevent the gun from firing when a bullet would otherwise strike a propeller blade. Although German authorities were impressed with Fokker’s demonstration of the mechanism at the factory, they demanded that he personally demonstrate it in flight against an Allied aircraft before they would adopt it, even though this would violate his status as a neutral noncombatant. After making several flights over the next 8 days, Fokker refused to fly further. German officials finally relented and allowed Fokker to instruct Lieutenant Oswald Boelcke how to operate the gun.
The introduction of the Eindecker with its synchronized machine gun in late July 1915 transformed air combat. Although the E.I had a relatively slow speed at 81 mph compared with the Morane- Saulnier Type N’s 90 mph and took 7 minutes to climb to 3,000 ft, it had good maneuverability and its round fuselage and thin wings made it hard to detect. The first two Eindeckers were sent to Feldfliegerabteilung 62 at Douai, where both Boelcke and Max Immelmann were based. Although the Germans had eleven Eindeckers in service by the end of July, they made a tactical error of distributing two to each Abteilung rather than concentrate them in a single squadron, which would have had a more devastating impact upon the Allied air forces.
After Boelcke and Immelmann began shooting down Allied planes in fairly rapid fashion, an enthusiastic German High Command pressed Fokker to speed up production of Eindeckers as fast as he could.
Although the Germans had relatively few Eindeckers in service on the Western Front—just 55 at the end of October and just 86 at the end of December 1915—their impact revolutionized the war in the air. Armed with this technologically superior aircraft—an updated version, the E.II, replaced the 80 hp Oberusel rotary engine with a 100 hp version, increasing speed to 87 mph and the ceiling to 12,000 ft—Immelmann and Boelcke would formalize air combat tactics into a science. Immelmann introduced the turn named after him. After diving to attack an enemy plane, he pulled back up into a loop and upon reaching the top, half-rolled to an upright position, above and behind and in the opposite direction of the enemy target. By executing a stall turn, the pilot could then execute a second dive attack on the enemy plane. Boelcke developed his famous Dicta that remained relevant for decades to come: attack from above with the sun at your back; use clouds to conceal your approach; pull within close enough range to hit the target but avoid being hit yourself; turn toward an oncoming attacker to close the distance; and back sharply from a rear attack. Although the Allies would introduce a new generation of fighters in the late spring of 1916—the Nieuport 17 was the first with a synchronized gun—that were more than a match for the Eindecker, the Germans would soon respond with a new generation of fighters of their own—the Albatross D.I— setting off a continuing technological race that would cause the advantage to swing back and forth until the war ended. The generations of fighters that succeeded the Eindecker will be discussed in greater detail, but it is important to note how the introduction of the Eindecker impacted tactics, strategy, and organization.
In response to the so-called Fokker scourge, in which the British lost 43 aircraft between August 1915 and January 1916, the Allies were forced to change tactics until they could introduce a comparable fighter. Where pilots had previously been given a tremendous amount of discretion in search-and-destroy missions, the Eindecker forced Allied units to begin flying in formation and provide escort for reconnaissance aircraft. More significant, after taking over command of the RFC in France on 19 August 1915, Major General Hugh Montague Trenchard emphasized the need for taking aggressive offensive action in the air by concentrating Allied fighters into fighter squadrons rather than scattering them piecemeal among squadrons. Even though Allied fighters were still inferior to the Fokker Eindecker, their concentration in numbers offered a better defense until new fighters were introduced.
By 1916 all powers had gained enough experience to issue tactical guidelines. One of the most important lessons learned and applied was the importance of formation flying and fighting in groups rather than venturing out alone. Mutual support, particularly against attack from the rear and in identifying enemy planes, was another major advantage of fighting in groups. Squadrons generally flew in a “V” formation with the flight leader in front and those behind flying at different altitudes. Stacked squadrons flying above each other provided protection from overhead attacks. Needless to say, coordination was crucial to success, especially because communication was limited to hand or wing signals. Whereas dogfights involving squadrons or groups of squadrons against one another are the most remembered aspect of the air war in the First World War, fighters were more frequently engaged in less spectacular activity: patrolling the line and escorting bombers or reconnaissance aircraft. Escort duty was generally reserved for junior pilots, whereas more experienced fighters preferred flying in small groups of two to three planes to hunt for victims. In addition, fighters sometimes provided support to ground troops by strafing enemy lines—a role that will be discussed in greater detail later. Although the fighter had definitely changed the war in the air by the start of 1916, the two epic battles of Verdun and the Somme would provide new directions in their use.