It is believed that one of the most serious blows to the defense capability and military potential of Nazi Germany was inflicted by its military leadership and designers of military equipment. All of them were constantly "sick" with new ideas, sometimes completely unrealizable. As a result, part of the forces and production facilities that could be used for the benefit of the front were engaged in various types of "wunderwaffe". As the spring of 1945 showed, in vain. One of the items of such extra expenses was vertical take-off aircraft, designed to intercept enemy bombers. Several projects of similar equipment were created, none of which, however, came close to mass production. Despite their excessive originality and the later revealed futility, these projects are still worth considering.
Bachem Ba-349 Natter
Actually, the idea of using rocket-powered aircraft to intercept enemy aircraft appeared in the mid-thirties. However, until a certain time, technologies did not allow starting serious work in this direction. However, time passed, the industry developed, and already in 1939 W. von Braun prepared a draft design for a missile fighter. It should be noted that von Braun, being an ardent supporter of rocketry, in his project combined the ideas of an airplane and a rocket as much as possible. Therefore, the proposed aircraft turned out to be very unusual for that time, as well as for the present.
The aircraft with a spindle-shaped streamlined fuselage, wing and tail of small aspect ratio was supposed to take off vertically, like a rocket. This proposal was based on the absence of the need for a long runway. After takeoff, the rocket engine provided the interceptor with sufficient speed to enter the meeting area with the target, several approaches to it and go home. The idea was bold. Even too brave to undertake its implementation. Therefore, the military leadership of Germany put the project on the shelf and did not allow von Braun to engage in any nonsense, instead of projects that were really important for the country. Nevertheless, von Braun kept in touch with the designers of other firms. Soon after his superiors refused, he shared his ideas with Fieseler engineer E. Bachem. He, in turn, proactively began to develop the idea under the index Fi-166.
For several years Bachem worked on the project of his vertical take-off fighter, waited for the creation of a suitable engine and did not try to advance his development. The fact is that the early developments on the Fi-166, as well as von Braun's idea, were rejected by the Reich Aviation Ministry. But the engineer did not stop working in the chosen direction. They started talking about the Fi-166 project again in the spring of 1944. Then the Reich ministry demanded from the country's aviation industry to create a cheap fighter to cover important objects. In addition to the possibility of large-scale production, the customer also wanted to see flight characteristics no worse than existing equipment.
It was then that the developments in the field of rocket fighters were needed. A preliminary draft, called BP-20 Natter ("Viper"), has been submitted to the Ministry. Initially, officials of this organization rejected Bachem's project in favor of others, as it seemed to them, more promising. But then events began in the style of political detectives. Far from being the last person at the Fieseler firm, Bachem, through the famous pilot A. Galland and a number of other high-ranking officials, managed to get to G. Himmler. The latter became interested in the idea and just a day after talking with the designer, documents were prepared on the deployment of work.
Bachem was given full command of a small factory and a group of specialists in aerodynamics, materials and rocket engines. In just a few months, the original BP-20 was heavily redesigned. First of all, they changed the way of using the aircraft. Initially, it was supposed to take off from a vertical guide, reach the target and fire a salvo of small unguided rockets. Left without ammunition, the pilot had to make a second approach to the enemy and ram him. To save the pilot, an ejection seat was provided, and the engine compartment was fired back before the collision. After disconnecting the engine and part of the fuel system by parachute, they would descend to the ground, and they could be put on a new aircraft. It all looked too complicated. In addition, none of the available seats simply did not fit into the cockpit of a disposable interceptor. Therefore, the battering ram was removed from the concept of using the "Viper" and the way the pilot was rescued was changed.
Ultimately, Natter took on the following look. Solid wood glider with metal rudders and liquid propellant rocket engine. The wing and empennage had a relatively small span and served only for control during takeoff. However, their area and lift were sufficient to support planning and landing. Requirements for simplifying the design, as well as a number of features of the liquid-propellant engine did not allow equipping the "Viper" with the chassis, moreover, it was simply not needed. The fact is that after using up the ammunition, the pilot had to throw off the nose of the fuselage and shoot the engine. A small capsule with a pilot and rocket engine descended on their own parachutes. The rest of the plane fell to the ground. In the aft fuselage there was a Walter WK-509C engine, which provided two tons of thrust. The entire middle part of the fuselage was occupied by fuel and oxidizer tanks of 190 and 440 liters, respectively. To defeat targets, "Nater" received an original launcher for unguided missiles. It was a structure made of polygonal tubes. For use with Hs 217 Fohn missiles, it was planned to put a launcher with 24 hexagonal guides. In the case of the R4M, the launching "channels" were already quadrangular and mounted in the amount of 33 pieces. The peculiarities of the flight of such ammunition made it possible not to be smart with a sight - a wire ring was placed in front of the visor of the cockpit.
In the course of final development, the new interceptor received an updated index - Ba-349. It was under this name that he entered trials in November 1944. At the same time, the first test flight was made, in which the Viper was towed by an He-111 bomber. The first vertical run was scheduled for December 18th. The experienced interceptor was loaded with ballast to normal takeoff weight. In addition, due to the relatively low thrust of its own rocket engine, the Natter had to be equipped with six boosters with a total thrust of six tons. On that day, Ba-349 did not even come off the rail. The fact is that due to a manufacturing defect, the accelerators could not gain the required power and the plane, jumping on the spot, sank down.
Further events developed rapidly. Four days after the failure, the first test unmanned takeoff was made. On the same day, the Reich ministry commission announced its decision not to launch the Ba-349 into series. Due to the fundamental flaws in the design and method of application, no prospects were seen in it. Nevertheless, Bahem was allowed to complete the ongoing tests. During the winter of 44-45, 16-18 unmanned launches were carried out with the development of various systems. The first manned flight took place on March 1, 1945. During the first phase of the flight, the lantern was blown off by a stream of air, after which the plane turned over and headed for the ground. Test pilot L. Sieber was killed. The most likely cause of the crash was considered the unreliable fastening of the flashlight - at first it was torn off, and then the pilot lost consciousness. However, after a short break, the Germans managed to carry out three more manned flights. After that, a number of changes were made regarding the engine and weapons.
A total of 36 copies of the "Viper" were collected and another half dozen remained unfinished on the stocks. At the stage of preparation for military trials (Bachem still hoped to push the Ba-349 in the Luftwaffe), all work was interrupted due to the successful offensive of the armies of the anti-Hitler coalition. Only six Nutters survived the last days of the war. Four of them went to the Americans (three are now in museums), and the remaining two were divided between Great Britain and the USSR.
Heinkel lerche
Through the efforts of some historians, the most famous German project of a vertical take-off interceptor was the development of the Heinkel company called Lerche ("Skylark"). The creation of this flying machine went simultaneously with the final work on the project described above. In the same way, the goal coincided - the launch of the production of a simple and cheap fighter to cover important objects in Germany. Only here it was not possible to achieve simplicity and cheapness. Let's dwell on the "Lark" in more detail.
The Heinkel engineers followed the same path as E. Bachem, but chose a different power plant, a different layout, etc. right down to wing aerodynamics. The most unusual and noticeable element of the Skylark's design is the wing. This unit was made in the form of a closed ring. As conceived by the authors of the idea, such an aerodynamic layout retained its flight performance with smaller dimensions. In addition, the annular wing promised the possibility of hovering and improved the efficiency of the propellers. Two propellers were located in the middle of the fuselage inside the wing. The propellers were planned to be driven into rotation using two 12-cylinder gasoline engines Daimler-Benz DB 605D with a capacity of about 1500 hp. With an estimated take-off weight of 5600 kilograms, the Heinkel Lerche was supposed to carry two 30 mm MK-108 automatic cannons.
By the fall of the 44th, when tests were already carried out in wind tunnels and it was possible to begin preparations for the construction of a prototype, a number of shortcomings became clear. First of all, questions were raised by the propeller group. Existing propeller engines could not provide enough power for takeoff. Some sources mention that just for takeoff, this device needed a power plant one and a half to two times more powerful than it had. In particular, and therefore in February 45th, the development of the Lerche II interceptor was started. It was planned to equip it with new engines with a capacity of more than 1700 hp. and equipment for the use of X-4 guided missiles.
But in February 1945, the outcome of the war was already clear - only the specific timing of its end remained in question. As a result, several innovations at once did not work. Germany did not receive a revolutionary new interceptor, the promising, as it seemed then, the annular wing did not have the desired effect due to the lack of engines of the required power, and the recumbent position of the pilot (in horizontal flight) remained a sign of purely experimental machines. In addition, several decades later it became clear that the transition from horizontal to vertical flight is a very difficult process, which is not within the power of all pilots. But Heinkel did not come to such problems. The thing is, the Lark was not even built.
Fokke-Wulf Triebflügeljäger
The third project, which is worth considering, was created simultaneously with the previous ones under the leadership of the famous designer K. Tank. If the authors of the "Skylark" abandoned the straight or swept wing in favor of the circular one, then the engineers of the Focke-Wulf company went even further. They completely abandoned the wing as such and replaced it with a large propeller.
The propeller blades were of solid size and somewhat resembled a wing. The power plant was no less original. Instead of a complex kinematic diagram with a gasoline engine, power transmission system, etc. the Focke-Wulf designers came up with the idea of equipping each propeller blade with its own engine. Three ramjet engines designed by O. Pabst with a thrust of about 840 kgf had to work throughout the flight and rotate the propeller. Due to the absence of any mechanical connections between the propeller and the fuselage (if we do not take into account the bearings), the structure was not subject to a reactive moment and did not need to be parried. The propeller with a diameter of 11.4 meters had to be untwisted with the help of an auxiliary liquid engine of low power, after which the direct-flow ones were turned on.
This unusual aircraft was named Triebflügeljäger. It consists of several parts, which can be translated into Russian as "Fighter propelled by a wing." In general, the "wing-shaped" design of the blades fully explains this name. According to preliminary calculations, the device should have had a total take-off weight of no more than two and a half tons. The blowing of the Triebflügeljäger models in wind tunnels has shown that it is capable of level flight at speeds from 240 to 1000 kilometers per hour. The original propeller wing provided a good ceiling for that time - about 15 kilometers. The preliminary design of the "Three-Wing Fighter" provided for the installation of two MK-108 cannons (caliber 30 mm) and two 20-mm MG-151 cannons.
Obviously, the beginning of the development of such a bold and new design in the early summer of the 44th did not go to the benefit of the project. Until the end of the war, Fokke-Wulf only managed to complete the design and work out the aerodynamic appearance of the car. The construction of a prototype was absent even in the plans of the company. Therefore, at present there are only a few photographs of blowing machines and many drawings of the alleged "combat use".
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All three projects described above share several characteristic points. They were all too bold for their time. All of them were launched too late to have time to participate in the Second World War. Finally, the course of the war hindered the normal conduct of all projects, which by the 44th year was far from favoring Germany. As a result, all programs led to the construction of only a few dozen experimental Ba-349s. The German aviation industry was no longer capable of anything more.
