The First World War gave an unprecedented impetus to military science. Man in his ability to kill other people has never been equal. The war only confirmed this thesis. Having started a conflict with rather primitive aircraft, which often carried no weapons at all and performed mainly reconnaissance tasks, the military and industry very quickly brought aviation to a completely new level.
In the first air battles, aviators often fired at each other with revolvers and pistols, while the battles literally took place at pistol-shot distance. However, already in 1914, the first synchronizers were presented, which made it possible to fire through a rotating propeller without the danger of damaging it. In 1915, the first synchronizers appeared on combat aircraft. First in French and then in German.
The appearance of the first synchronizers
In fact, the question of how planes shoot through a rotating propeller and do not shoot off their blades has popped up in almost every person's head at some point. Almost everyone who was interested in aviation in the pre-jet era was looking for an answer to this question. At the same time, interest in the topic was fueled by a large number of military-themed films, which continue to be filmed to this day.
The answer to the question that torments people just getting acquainted with the world of aviation is the "synchronizer". This is the name of the mechanism invented during the First World War. The synchronizer itself was a device that allowed the pilot to fire through the area that was thrown by the aircraft's propeller, without the danger of damage to the propeller by bullets, and then by shells.
The appearance of such a device was dictated by the very development of aviation and the experience of the very first air battles. At first, when the planes were planned to be used only for reconnaissance and adjusting artillery fire, there were no particular problems, and the pilots really did manage with personal weapons. But the concept of the use of aviation changed rapidly already in the course of hostilities.
Soon, turrets with a machine gun or machine guns that could shoot above the propeller began to appear on planes. Separately, it was possible to distinguish models with a pusher propeller, which did not interfere with firing directly along the course. At the same time, the technology for placing weapons in the wing of an aircraft simply did not exist at that time. There were no remote control systems either.
A turret with a machine gun, of course, made life easier in battle, but it allowed fire only in the rear hemisphere, excluding the frontal zone, which is most relevant for all fighters. The first solutions to the problem with directional shooting through a rotating propeller were proposed as early as 1913-1914. It is believed that the first such devices were proposed by the Swiss engineer Franz Schneider and the French Saulnier.
Already during the war, the idea of Saulnier was developed by the French pilot, athlete and hero of the First World War Roland Garosse. Today this name is familiar to people even as far as possible from aviation. It is in his honor that the tennis tournament is named - one of the four Grand Slam tournaments held in Paris.
The device, designed and implemented by Roland Gaross, rightfully marked the birth of a fighter aircraft in the classical sense of the term. Gaross proposed a "cutter" or "deflector" of bullets. The system was as simple and utilitarian as possible, but it allowed shooting through a rotating propeller. Visually, it consisted of metal corners that were fixed at the base of the propeller blades so that the bullets ricocheted into an area safe for the aircraft and pilot when they hit.
The design had its drawbacks. About 7-10 percent of the bullets were lost like this, hitting the reflectors. At the same time, the propeller added weight, the load on the engine increased, which led to premature failure. The effective power of the propeller also dropped by 10 percent. But all these shortcomings were compensated by the possibility of firing along the course of the aircraft.
In February 1915 at the disposal of Sous-Lieutenant Roland Garros was given a single "Moran Parasol", which received a new system with cutters on the propeller blades. Already on April 1 of the same year, the innovation showed itself in all its glory. At an altitude of a thousand meters, the pilot shot down a German reconnaissance aircraft "Albatross", and then in a short time won a number of aerial victories.
Fokker's Beach
On the morning of April 18, 1915, Garossus made an emergency landing in German-occupied territory and was captured. Before the arrival of German soldiers, he managed to set fire to his plane, but he was not completely destroyed. The Germans were given the opportunity to study the French propeller-firing device. It quickly became clear that the chrome-plated German bullets carried both the reflectors and the propeller, in contrast to the copper French bullets.
In any case, the Germans did not copy the French development. At the same time, work on the creation of synchronizers was carried out in many European countries even before the start of the war. Germany was no exception. The mechanical synchronizer was invented for the Germans by the Dutch aircraft designer Anton Fokker. He equipped the Fokker E. I.
The aircraft was a bracing monoplane, a further modification of the Fokker M5K reconnaissance aircraft, which, in turn, was created on the basis of the French airplane Moran Saulnier G. The main difference from both the M5K model and the French aircraft was a synchronized machine gun.
Fokker E. I - became the first full-fledged production fighter capable of firing through propeller blades. In air battles, this gave the German pilots a strong advantage over the Allied fighters, who had less convenient machine guns. By the end of the summer of 1915, the superiority of the Germans in the air had become absolute. The British press even came up with the name "Fokker Beach" for the new German aircraft, which reflected the heavy losses that the British Air Force had suffered in the battles with the Germans.
Due to the appearance of a mechanical synchronizer, the new German fighter was dangerous even for French armed fighters, including models with a pusher propeller. Even with a machine gun on board, such vehicles lacked the protection of the rear hemisphere. German pilots, who went to the tail of French aircraft, shot the enemy with impunity, hitting the engine.
The simplest Fokker device provided the Germans with complete superiority in the skies until the spring of 1916, when one of the aircraft made an emergency landing in French-occupied territory. The British and French quickly copied the device and were able to fight the Germans on equal terms.
Fokker mechanical synchronizer device
Fokker's mechanical synchronizer made it possible to link the firing of the machine gun with the rotational speed of the propeller. The design was reliable and simple and settled in the aircraft industry for a long time. Fokker linked the trigger to the rotor thrust, allowing the bullets to fly past the rotating blades. In fact, he presented a simple and elegant cam mechanism, which once per rotation "turned off" the trigger at the moment when the propeller blades were at a certain point.
The designer installed a disc with a protrusion on the rotating part of the engine. When rotating, this cam moved the thrust, which was associated with the trigger mechanism of the machine gun. Each time a shot was fired immediately after the blades passed in front of the machine gun barrel. So Fokker solved two main problems: ensured the safety of the propeller and achieved a high rate of fire. Although the rate of fire here directly depended on the engine speed.
The synchronizer definitely required fine tuning after installation on the aircraft, but it was so successful that it completely changed the course of the air war, becoming a role model for many years. Later, by the beginning of World War II, more advanced electronic synchronizers appeared on fighters, which made it possible to increase the rate of fire.
At the same time, even by that time, there could be problems with synchronizers. For example, they appeared on the Soviet MiG-3 fighter, which began arriving en masse in units just before the start of the Great Patriotic War. Failures of synchronizers in 1941 happened on this model quite often, which led to the shooting of the propeller blades with large-caliber bullets. At high flight speeds, such a defect could lead to the loss of the aircraft and the death of the pilot.
Synchronizers were completely abandoned only after the transition from propeller-driven aircraft to jet aircraft, when these devices lost their relevance. This happened already in the 1950s.
