Secret Weapons (5 page)

A version of the Komet was also produced in Japan. Two German submarines were sent to Japan with parts and designs; one did not arrive, so the Japanese had to improvise some of the components. The Japanese version of the Me-163B Komet was the Ki-200 Shusui produced for the Imperial Japanese Army by Mitshubishi. It was equipped with two 30mm (1.18in) Ho 155-II guns. A version known as the J8M was built for the Navy which had its first flight on 7 July 1945 with Lieutenant-Commander Toyohiko Inuzuka as pilot. On returning to base, the plane clipped a building and crashed in flames, killing the pilot. On 15 August 1945 the Japanese war ended and so did the Japanese Komet.

The Komet needed an airfield from which to fly, and during the later stages of the war Allied warplanes were sent to bomb the runways so that Komets could be prevented from operating. The answer was to use a compact launch pad, like a rocket; this would be far harder to detect than a conventional launch pad, and even more difficult to destroy with bombs. As design work proceeded, the idea of a vertical take-off rocket fighter began to emerge. By the end of the war, this revolutionary idea had been realized and prototypes were already in production, nicknamed the
Natter
(Viper).

In August 1944 the Chief of Development for the German Air Ministry (Reichsluftfahrtministerium), Colonel Siegfried Knemayer, was asked for new proposals for a hard-hitting plane that would be difficult to disable, and he listed the criteria that such an aircraft should satisfy. The result was the Natter. Knemayer decided to take a cheap rocket-powered aircraft that could fly near the speed of sound, fit it with armaments, and blast it from a vertical launch to attack enemy planes. A full set of control surfaces and landing gear would not be necessary, as the pilot would simply bail out and return to earth by parachute as soon as the attack was over.

Work began at the Bachem-Werke in Waldensee in 1944 and the result was the Ba-349 Natter, which translates as Adder or Viper. This was destined to become one of the oddities of World War II. It was intended to bring down the formations of Allied bombers that were relentlessly pounding German factories and cities in the latter years of the war. The Ba-349 followed a simple design that even semi-skilled workers could construct in less than 1,000 hours. The control surfaces were confined to the tail fins, making it easy to fly and simple to manufacture. It was powered by a Walter 109-509A rocket motor generating 3,700lb (1,700kg) of thrust and was equipped with 4 Schmidding 109-533 solid-fuel booster rockets fixed to the fuselage to assist the launch. Fully laden, the Natter weighed 4,800lb (2,177kg) of which 1,400lb (635kg) was fuel. The plane measured 21ft 3in (6.5m) in overall length and was fitted with two sets of 12 solid-fuel 2.84in (73mm) rockets to be fired in a single volley.

Flight testing of unpowered prototypes began in November 1944 at Neuburg an der Donau. The first was towed up to nearly 10,000ft (3,000m) by a Heinkel He-111 bomber and the test pilot, Erich Klöckner, reported that it handled well. In December 1944 vertical take-off tests were started at Truppenübungsplatz near Lager Heuberg yet the first manned flight in March 1945 soon ran into difficulties and the pilot, Lothar Sieber, was killed when his parachute failed to open. Problems were experienced from the start; even with the rocket boosters the velocity of the Natter when launched was too low for the control fins to work effectively, so steel vanes were fitted to deflect the rocket exhaust. They were prone to melting in the heat, so they were filled with water; although the water soon boiled away and the vanes were destroyed by the temperature of the rocket fame, the Natter had – by that time – gained enough speed to be conventionally controlled.

As the war was ending, the factory was closed down and a Dutch designer named Botheder was dispatched to take four of the Natters to a new base. Botheder was reported to have a ski chalet, the Einen Achalpe, in the nearby mountains and it was apparently agreed that this is where the teams would rendezvous after the troubles were over. In the event, he was intercepted en route to this eagle’s lair by advancing American forces in May 1945 and the truth was out. Botheder explained that the remaining staff members were a test pilot named Zeubert, who had successfully flown an unpowered gliding version of the prototype, an engineer called Granzow, who was in charge of the rocket motor, and a coordinator who kept a watchful eye on the proceedings. This man’s name was Schaller, and Botheder said he was convinced he was a Nazi party member put there to report back, secretly, on everything that was happening.

In total, 36 Natters were constructed during the war. Of these, 18 were used as test vehicles and two were destroyed in crashes. Ten were destroyed at the end of the war. One Natter was taken by the British, and another by the Soviet Army. Four of the surviving Natter rocket planes were taken back to the United States. One of these was test-fired, unmanned, from the Muroc Army Air Base in 1946. It was the first manned surface-to-air interceptor. Only three of the Natters have survived. There is a Ba-349A at the Deutsches Museum in Munich, now painted in the markings of one of the unmanned test aircraft. A second Natter is in the collections of the National Air & Space Museum in Washington DC. There is also a Ba-349A on show at the Planes of Fame Museum in Chino, California; this one, however, is only a wooden copy. In Japan during the last days of the Pacific War, the Mizuno aircraft company began constructing an aircraft that was based on the concept of the Natter. The Mizuno Shinryu interceptor rocket plane was the result. It would have been equipped with rockets fired from under its wings and could also have been fitted with a warhead in the nose, to be used for a suicide attack. Development was still underway at the end of the war.

And this provides us with a fascinating thought. The rate at which these new designs were realized seems extraordinary in a modern world, hide-bound by administration, bureaucracy, health and safety directives and the need to comply with regulations. From the viewpoint of wartime Germany, work began too late. Had the Axis powers begun work on their secret weapons earlier, many of these extraordinary innovations would have been proved a success and the course of the war might have turned out very differently.

Many of the secretly designed planes of World War II came from more conventional sources. For example, the Heinkel He-111 had been developed in peacetime in direct defiance of the Treaty of Versailles. Although claimed to be a commercial transport aircraft it had been covertly designed for easy conversion to military purposes. It became the Luftwaffe’s standard twin-engined bomber and was produced in scores of different variations. Typical of the type were planes with a wingspan of 82ft (25m) and length of 52ft 6in (16m), with an operating speed of 280mph (450km/h). In 1940, 750 of the planes were under construction; the number doubled during 1942, with the result that this bomber was produced in greater numbers than any other German plane during the early years of the war. It took part in the Battle of Britain, but the superiority of the British fighters proved that its time had passed. It had poor manoeuvrability, limited operating speed, and its armaments were inferior. However, it could often remain flying even when badly damaged and so was eventually employed on many fronts during the war. As well as serving as a bomber it was useful as a transport aircraft on the Eastern, Western, Mediterranean, Middle East and North African Fronts, and was successfully used to drop torpedoes in the North Atlantic campaign. As the war ended, the He-111 re-emerged in a different guise, ensuring the design remained in use for many years. It was produced in Spain under licence by Construcciones Aeronáuticas SA, and the first of these planes flew before the war ended in May 1945. After the war, since it was no longer possible for the manufacturers to obtain the Junkers engines, they installed the Rolls-Royce Merlin 500 instead. Over 170 Merlin engines were ordered in 1953 alone. A nine-passenger transport aircraft, the 2.111T8, was to follow. Many of these planes found a use in movies about World War II, repainted to look like the original Heinkels. The Spanish planes continued in daily use until they were finally withdrawn from service in 1973.

The strangest version of the He-111 was the top-secret heavy-duty version designed to tow gliders filled with tanks, artillery and troops. It was manufactured as a pair of conjoined He-111 aircraft with a common wing upon which a fifth engine was mounted. The entire wingspan was some 125ft (38m) and the pilot flew the plane from a cockpit in the left-hand fuselage using identical, linked control levers. Towing a glider of over 35 tons, this twin aircraft was said to have flown to 30,000ft (9,100m) in 1942. The large numbers of these vast tow-trucks that would have been necessary for large-scale invasions were never produced. Certainly the handling and aerodynamics of this bastard giant would have been intimidating at the very least.

Following the success of the He-111 came the He-115, a seaplane comparable to the Sunderland Flying Boat that was produced in large numbers by the British. The He-116 was designed for long-distance cargo transportation and was used for flights to Japan; the He-117 and He-118 were tactical developments that never got off the ground and the He-119 – which could travel up to 375mph (600km/h) and was to be powered by two DB-603 engines – was never put into production.

A revolutionary high-altitude bomber was proposed as the He-274, intended to be a four-engined bomber with a number of advanced features. Development began in October 1941 and the prototypes of the new bomber were contracted for construction in France by the Société Anonyme des Usines Farman (SAUF) firm in Suresnes, near Paris. The He-274 dispensed with twin coupled engines and instead featured four independent DB-603 A-2 engines with a greater wingspan and a lengthened fuselage. The cockpit would be double-glazed and pressurized to maintain an air pressure for the crew equivalent to an altitude of 8,200ft (2,500m). The aircraft was designed to fly up to 47,000ft (14,300m), far higher than any Allied fighter. In 1937 a Bristol Type 138 high altitude monoplane had reached a world record altitude of 49,967ft (15,230m) but this was an experimental aircraft; the highest a Spitfire XIX ever flew was 44,000ft (13,400m).

As a consequence, the He-274 would require little defensive armament and the plane was designed to carry a forward-firing 13mm (0.51in) MG 131 machine gun with a further two pairs of these guns in turrets. Work on manufacture of the prototypes did not start until 1943 and the advance of Allied forces on Paris in July 1944 forced the evacuation of the German employees before the first flight had taken place. Here too, the German technology pointed to the future. After the war, the French Air Force (Armée de l’Air) finished building the first He-274 and renamed it the AAS-01A. The second prototype was flown in December 1947 AAS-01B. Both were employed as test-bed mother ships for the launch of rockets and advanced jet planes at high altitude, and were in use until they were broken up at the end of 1953.

These amazing aircraft clearly show that Ernst Heinkel was a leading innovator on many fronts, and the best example of this is the introduction of the jet fighter. Jet-propelled planes could have radically altered the course of the war, but they arrived on the scene too late to make a crucial difference. The origin of the aircraft jet engine dates back to July 1926, when a young British engineer named A. A. Griffith published a paper on jet turbines. The idea was followed up by Frank Whittle, then an enthusiastic Royal Air Force (RAF) recruit, but Griffith dismissed the idea of a jet plane since he was convinced that a turbine could never generate the efficiencies needed for flight. Undeterred, in January 1930 Whittle took out a patent for the first jet engine. It attracted little interest with the RAF and they placed no restrictions upon the concept. Whittle made great progress as a pilot, and yet although companies showed some interest in his proposals for a jet plane none were willing to put up the money necessary to build a prototype.

During the following year, an Italian experimenter named Secondo Campini sent a paper on jet propulsion to the Italian Royal Air Force (Regia Aeronautica Italiana) and in 1932 he demonstrated a jet-propelled boat on the Venice lagoon. In 1934 he received the agreement of the Italian Royal Air Force for the development of a jet aircraft. Campini commissioned the Caproni factory to build his prototype. On 27 August 1940 test pilot Mario De Bernardi took the plane into the air and the World Air Sports Federation (Fédération Aéronautique Internationale) recognized this at the time as the first successful flight by a jet aeroplane, until news came of the Heinkel He-178 V1. This had flown for the first time in August 1939, powered by the HeS-3B engine invented by a German designer named Hans Joachim Pabst von Ohain. As we shall see, this highly innovative aircraft would give rise to a revolution in aircraft design – one we are still experiencing today.

However, the reality is that Campini’s aircraft did not have a jet turbine at all. His design featured a 670hp (500kW) Isotta Fraschini piston engine which drove an air compressor, forcing air into the combustion chamber where it mixed with a spray of fuel. Although the exhaust gases propelled the device forward, the use of a piston engine as the compressor means that it was not a jet turbine. Another Italian named Luigi Stipa also designed the Stipa-Caproni experimental aircraft in 1932, which had a ducted fan, and he also tried to claim it as the first jet aircraft. Both his plane and the Caproni-Campini used a jet of gas to propel the plane along, but neither was a pure jet turbine.

Meanwhile, in Britain, Whittle was still trying to develop his jet turbine idea, and in 1934 he was authorized to take the two-year engineering course at Peterhouse College, University of Cambridge, where he graduated with a first-class degree in Mechanical Sciences. Whittle received a note in the mail to remind him that his patent for a jet engine was due for renewal in January 1935. He could not afford the £5 fee. The Air Ministry told him that it was not interested in funding the renewal either, and so the patent lapsed. However, in September 1935 Whittle was introduced to two investment bankers at O. T. Falk & Partners, Sir Maurice Bonham-Carter and Lancelot Law Whyte. Whittle explained that a reciprocating engine, with its metallic components jerking up and down, seemed to him condemned to extinction. He insisted that the smooth-running jet turbine was obviously the way ahead. Whyte felt that this was a proposal of sheer genius, and in January 1936 Power Jets Ltd was formally established.