High-Speed Disc Interceptor

The High-Speed Disc Interceptor (HSDI) is a little known Soviet aircraft that was instrumental during World War II.  In this article, we take a closer look at this unusual vehicle.

The High-Speed Disc Interceptor (HSDI) was constructed in the USSR in 1940. However, the actual history of this unique aircraft dates back to June 30^th 1908. There was an enormous explosion that day near the river Podkamennaya, Tunguska, the nature of which has been argued ever since. The phenomenon itself became known as the ‘Tunguska Event’ or ‘Tunguska Meteoroid’.

The first Soviet scientific expedition, headed by Leonid Alekseevich Kulik, came to the place of impact in 1927. Mr. Kulik was the advocate of the theory that the Tunguska phenomenon was of meteorite origins. From 1927 until 1936 he arranged six scientific expeditions to Podkamennaya, Tunguska, and in 1941 he planned the seventh. However, he didn’t manage to find any traces of the meteorite. Instead, in the soil samples brought to Moscow between 1929 and 1930, he found traces of a substance of obviously extraterrestrial origin. The substance was thoroughly studied and analysed in the USSR Academy of Sciences. It was found out that the substance had unique attributes. In particular, Megravel, which the material became known as, would create a powerful anti-gravity field when under the influence of electromagnetic radiation.  This development opened up new horizons for aviation development.

One such project was the development of the ultra-high-speed electromagnetic engine, a device which could consume Megravel as fuel. Subsequent expeditions to the place of the Tunguska meteorite collision were immediately deemed top secret. Therefore, all information concerning aircraft equipped with the new engine types is ambiguous and fragmented by nature. The name “antigravity craft” was first mentioned in documents from the Moscow Institute of Experimental Aviation in 1939. Antigravity craft, which were officially designated as High-Speed Disc Interceptors (HSDI), were equipped with ultra-high-speed electromagnetic Megravel engines. The first known interceptor model HSDI-13 was tested on one of the secret landfills near Vologda in September 1940. The figure “13” indicates that this model wasn’t the first in the list of institute developments, but little has been recorded about its predecessors.  Most likely they remained as projects on the paper.

Initially designers tried to construct aircraft of the traditional type using the new engines, but the power of Megravel engines was so great that at transonic speed, experimental airplanes lost control and simply fell into pieces in the air. Gradually specialists from the Institute of Experimental Aviation came to conclusion that the optimal shape of the ultra-speed aircraft was the shape of a disc. The model HSDI -13-1 was disc-shaped with a large propeller which rotated on top. All-in-all it made the aircraft look like a present-day helicopter. However, this type of construction resulted in severe vibration and poor antigravity craft controllability, especially at high speed. The exterior of the next model HSDI -13-2 looked like a wheel with flat spokes with an external rotating perimeter.  The speed and flight direction was controlled by changing the inclination angle of spokes. The new aircraft had perfect maneuverability characteristics and could take off vertically. It took 3 minutes to climb 11,000 meters high and reach a speed of 2300km/h, but there were still vibration problems.

Nevertheless, the problem with vibration was fixed with the construction of the HSDI-13-3 model. This aircraft consisted of three main parts: two shells rotating inside of each other in reverse direction, and the core which acted as a combat platform. The platform, which was kept stationary with help of gyroscopic gearing, had three crew members – a pilot, air navigator and gunner. Of course, the pilot was specifically trained in the control of antigravity craft. Initially the new design had coaxial machine-guns Super-SHKAS, located in the mobile armour turret.  The rate of fire of a single super-SHKAS was 3600 rounds per minute. However, it was later decided to replace the machine guns with the gun system GM-127U - 12.7 mm Multifunctional Nutshooter. Structurally, this gun looked like a fan with titanium blades which rotated with a speed of 7600 turns per minute, throwing out a great number of heavy steel bolts and nuts at the target with tremendous speed. These shells with wide dispersion acted like buckshot and could cover a large area, easily riddling any air target.

One of the most complicated technical issues which Megravel engine developers faced was the inability to start the engine until the aircraft was already off the ground. The head of secret landfills, where HSDI -13-3 was based, proposed a solution, putting forward the idea of a specific launch unit, where the disc interceptor could be installed. To make it work, the Red Army platoon leader simply had to turn the hydraulic lever, which set a powerful spring.  The craft was place on top of the spring, and was then launched at high velocity into the air – sufficient for engine start.

The first and the only documented case of antigravity craft HSDI-13-3 tactical deployment was registered on April 4^th 1942. On this day, the first Luftwaffe Air Force conducted the “Eis Stoß” operation by launching an attack on Baltic fleet battleships in Leningrad. The German plan was to launch the attack when the battleships were located right in the middle of the Neva River, and thus unable to evade the enemy fire. However, the Soviet intelligence service managed to find out the exact time that the operation was due to begin, and as a result, anti-aircraft artillery and fighter aviation were deployed with the battleships.  However, one antigravity craft was also sent to confront the German squadron, which consisted of 200 aircraft. The antigravity craft’s mission was to detect the enemies in time and open pre-emptive fire at the German attack aircraft.

It is evident that just one combat unit, even though far more advanced than the rest of the planes of the time, couldn’t stop such a massive air attack. During the quick air battle, the antigravity craft managed to destroy at least nine enemy planes: three Bf.109 fighters, four Ju.87 fight-bombers and two Ju.88, one of which was destroyed as a result of a ram attack. HSDI-13-3 was badly damaged, but it still managed to cross the front line and make an emergency landing in the swamp.  

Meanwhile, as a result of powerful fighters and anti-aircraft fire, more than 20 German aircraft were destroyed. The raid itself, as well as the whole operation, failed. The Baltic fleet battleships took little to no damage.  However, or greater note was the psychological shock that the German pilots experienced. Fearful stories from pilots spread throughout the Luftwaffe about attacks of a mysterious plane which looked like a saucer. The German army command ended up calling a special medical board, which included leading psychiatrists from Germany. As a result of extensive research, doctors came to conclusion that they were dealing with mass hysterical hallucination of personnel, which resulted from the peculiarities of Russian climate combined with extreme nervous tension, all inherent to battle actions in the East.

However, at the same time the Third Reich senior staff received a secret report about a new kind of flying craft, which had come into operation in the Soviet army. The information seemed to be really credible, taking into account the fact that Germans had themselves tested their own model of antigravity craft in February 1941, which looked very similar to HSDI-13-3-2.  The sudden appearance of HSDI -13-3 convinced the German scientists from “Sonderbüro-17” to speed up the development of the improved model of antigravity craft. They managed to make some advancements with the help of Austrian construction engineer, Viktor Schauberger, who developed a «bursting» engine, which supposedly consumed water and air instead of the fuel. The prototype device was equipped with the Schauberger engine and named “Repulsine”.  The first and the last experimental flight of this aircraft dates back to February 19^th 1945. The German antigravity craft climbed 15,000 meters high and reached a speed of 2200 km/h.  At the end of the war the “Repulsine” was destroyed and its developers disappeared. Even though the Allies found documents about the German antigravity craft, the scientists didn’t manage to reconstruct the aircraft.

As for the Soviet HSDI-13-3, its operational flights ended in the year 1943 due to the lack of Megravel  supplies. Subsequent expeditions to the place of the Tunguska meteorite didn’t result in the discovery of any further samples of the substance. Perhaps, this story will forever remain a mystery since the death of Leonid Alekseevich Kulik. At the beginning of war he joined the Militia. Later he was injured and died of typhoid in 1942.