Secret aircraft of the Luftwaffe

Some of the most original weapons created by German scientists in the Second World War belonged to the aerial sector. One of the first ideas was to build a rocket-propelled fighter, capable of quickly reaching operative altitude to later fall upon the enemy aircraft. The first operative fighter of this type was the Messerschmitt Me 163 A, a chubby-looking, single-seat and single-engine glider whose Walter R2 rocket engine was propelled by liquid fuel. In May 1941, this aircraft reached 960 kilometers/hour during trials, a prodigious result having in mind that the average speed of a fighter in that time was 530 kilometers/hour. In fact, despite looking chubby, the Me 163 was the fastest aircraft built during the Second World War. A second version, Me 163 B, served for testing enhanced engines that should increase the speed. The construction of an aircraft of such type required great technical skill and absorbed a lot of time; the Me 163, which effectuated its first flight in 1941, was not ready for service until the last months of the war. The few units that reached the battlefield were distributed in experimental airfields, to be tested against the Allied bombers. The Me 163 could climb to 10000 meters in less than 3 minutes, quickly diving then from above against the enemy bombers, shooting at them with its two 30-millimeter cannons. Pilots from the RAF and USAAF that engaged this aircraft testified about how dangerous it was due to its speed, which prevented the machine-gunners from firing with effectiveness at it. The other side of the coin was that the pilot in the Me 163 faced as well a notable difficulty when aiming at the bombers, due to the high speed; only few bombers could be shot down by the Me 163 pilots. Another drawback was that the rocket engine could deplete the fuel in few minutes and then the aircraft would have to glide towards the ground, being then defenseless and vulnerable to the enemy.



A second model of the rocket-propelled fighter was developed by Junkers, the Ju 263, but since the project remained in the hands of Messerschmit, the Ju 263 was rebaptized as Me 263. This was the definitive version of the rocket-propelled fighter for the German war industry, but the end of the war prevented its mass production.



Another project for a rocket-propelled fighter was the Bachem Ba 349 Natter, projected in August 1944 by the company Bachem, and designed as "interceptor for the defense of the sites vulnerable to the attacks of enemy formations". The Ba 349 would take off vertically from a ramp to carry its first and last mission, armed with 24 73 millimeters air-to-air rockets. After reaching its maximum operative altitude (11900 meters) at a speed of 680 kilometers/hour, the Ba 349 should fall upon the enemy bombers and shoot them down with the deadly high-explosive rockets. Finished the action, the pilot would jump with parachute while the aircraft would end either crashing on the ground or hopefully reaching land safely and in a reasonably intact condition since it was equipped with a parachute for that purpose. From the takeoff to the moment on which the pilot should leave the aircraft would pass just three or four minutes. Since this was a throwaway aircraft, it was built with extreme simplicity: a wooden structure assembled with staples and adhesive glue, containing a rocket-engine, a place for the pilot and accommodation for the rockets. The Ba 349 measured 5.7 meters in length and only 3.1 meters in wingspan; it looked like a hybrid between an aircraft and a primitive missile. It weighed 1.5 tonnes at the moment of takeoff.



Several prototypes of the Ba 349 were tested for flight in November 1944, but helped by another aircraft, a Heinkel bomber, that trailed them during the takeoff procedure. In February 1945 the Ba 349 had not yet been put in flight in an autonomous way, and the SS were losing their patience with the delay of the project; the manufacturers considered that the Ba 349 was still not ready to face an autonomous flight, but for avoiding the anger of the SS, they submitted to the request. Made under pressure, the test was a complete disaster: the prototype was launched from the ramp and then the engine exploded. At an altitude of about 100 meters, the cockpit disintegrated and the pilot died. The aircraft climbed for another 500 meters, turned and reversed, faced up and reached an altitude of 1000 meters, only for finally crashing against the ground. About 30 Natter had been built; of these, 18 were used in operations, trailed by the Heinkel bomber; one exploded during a speed experiment, another one exploded during takeoff, six more were destroyed to prevent their capture by the Allies and the remaining four were captured by the Americans in Austria. The Ba 349 project was, if not the most, one of the most disastrous ones carried by Germany, so dangerous that would fit better the Japanese mentality of those times.



This drawing of the Natter was gathered from original contemporary material.



The most practical and revolutionary achievement developed by Germans in aeronautics was the one of the turbojet engine. As it happened with some other innovations of that time, such as the radar or the infrared rays devices, the turbojet engine was being investigated in several nations; the progress of the studies would depend in the interest that the political authorities would put in authorizing or funding the projects. In Germany it was Heinkel the company that carried most of the works in regard to the development of a functional turbojet engine and aircraft. For starting the tests, Heinkel built an aircraft, named He 178, built with a rather aerodynamic shape, suitable for being flown at the high speeds expected. This aircraft was tested firstly with a rocket engine, the Walter R1 operating with liquid fuel and with a variable thrust from 45 to 500 kg. The test was positive, so the first Heinkel turbojet engine was installed in place of the rocket engine, to effectuate the attempt of the first flight of a turbojet in History. The success of this flight in August 1939 suppossed a technical revolution and gave to the Germans an edge in this field of investigation. But surprisingly, the German authorities showed no interest in this technology, a mistake that would delay its practical usage during the war. During the trials the He 178 had reached a maximum speed of almost 700 kilometers/hour at sea level, and the cruising speed was about 575 kilometers/hour. Despite official opposition, Heinkel continued the development in the field of turbojets with his own funds.



At the same time, the company Junkers was focusing in developing and perfectioning as much as possible their own turbojet engine, and did not attempt to build a dedicated aircraft for installing it; they adapted instead a Messerschmitt Bf 110. With this aircraft they started trials in the late 1941, attracting the interest of the Luftwaffe, because the course of the war was then not so bright as the German authorities had expected, and these were searching for new weapons that could decisively shorten the conflict. Later, the engines Junkers Jumo 004B-1 would be installed in a completely new aircraft, the Messerschmitt Me 262, which was the first turbojet fighter that entered operative service in History. Reaching a maximum speed of 870 kilometers/hour at 5500 meters of altitude, and armed with four 30-millimeter cannons and optionally with two R4M rocket launchers, this was a superb interceptor specialized in destroying heavy bombers. But the wrong judgement of Hitler, turning the Me 262 in a ground attack aircraft, would weigh like a slab in the record of this aircraft. The illustration below shows the turbojet Me 262 in comparison with the rocket- propelled Me 163.



On the other hand, BMW had been studying about turbojet engines already since 1934 and finally they experimentated their own engine in the summer 1940. When the Junkers engine was approved by the Luftwaffe, the BMW entered the contract as a supplier for Junkers. The Junkers Jumo 004B became the engine for both the Messerschmitt 262 and the Arado 234, which would be revolutionary for being the first turbojet bomber reaching operative status. The Ar 234, fitted with two Junkers Jumo engines, reached a maximum speed of 742 kilometers/hour. But in time BMW managed to have their project supported by the authorities, and the new version of the Ar 234 was fitted with four BMW 003A-1 engines; the Ar 234C could reach a maximum speed of 875 kilometers/hour and an operative altitude of 10200 meters. However, too few exemplars were built to contribute decisively in the war.



Another project for a bomber was the Focke-Wulf denominated 1000 x 1000 x 1000, because it was the intention of the designers to be capable of transporting 1000 kg of bombs to a distance of 1000 kilometers at a speed of 1000 kilometers/hour. To achieve such extraordinary speed, the structure was conceived with a very aerodynamic manta-like shape that was close to the one of modern stealth bombers, including the absence of vertical tails. Anyway, this interesting project was never realized and it is unknown if the technicians would have achieved in practice such theoretical prestations. It would seem that the ideas of the German engineers were then ahead of what contemporary technology was able to achieve.



Another grandiose project that ended in nothing was the Focke-Wulf Fw 03-10225, a strategic bomber that should have an operational range of 8000 kilometers - hence allowing it to reach the eastern United States coast - while transporting 3000 kg of bombs, and flying at a speed of at least 560 kilometers/hour at an altitude of 10700 meters. The propulsion plant would have consisted of four BMW 801D radial piston engines giving 1600 HP each. Defensive armament would consist of many guns of diverse calibers, hypothetically four 30-millimeter cannons, one 20-millimeter cannon, four 15 -millimeter machine guns and four 13-millimeter machine guns.



Returning to Heinkel and the turbojet fighters, it seems imperative to mention the He 162 Volksjager, aircraft projected in a record time in the late 1944. It was a very fast fighter, built with a simple manufacture and adapted so to unexperienced pilots. Single-engined aircraft, it was equipped with a BMW 003E-1 engine and could reach about 835 kilometers/hour at 6000 meters of altitude, reaching even 905 kilometers/hour if using short burst extra thrust. The armament consisted of two 20-millimeter cannons that were mounted in the flanks of the cockpit, which gave the He 162 a very modern appearance in that time. Only few exemplars were built before the end of the war.



The original concept of the Dornier 335 left apart the rocket and turbojet engines and gave a twist to the conventional usage of piston engines. Having a fore engine acting as tractor and a rear engine acting as propeller, this aircraft reached 763 kilometers/hour, a higher speed than any other piston-engine aircraft in that time. However, having two engines was not an optimal solution, since the extra engine added weight and took valuable space that could be used for storing fuel or devices. The Do 335 resulted as well larger than any other fighter in that time, reaching almost 14 meters in both length and wingspan. The armament consisted of one 30-millimeter cannon and two 20-millimeter cannons. Projected as nocturnal fighter, many experimental models were tested, but without reaching active service.





Article updated: 2015-07-01

Categories: Aviation - World War Two - 20th Century - [General] - [General]

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Website: Military History

Article submitted: 2014-10-16