Friday, January 7, 2011

Germans Pioneered Stealth Technology in 1944

Germans Pioneered Stealth Technology in 1944. Northtop (USA) copied on B2.

A cross section of the only surviving WW-II German Stealth Technology aircraft of 1944. Germans used charcoal dust with resin glue to make it invisible to Allied Radars.

A true copy replica of German WW II stealth bomber replicated by Northtop Corporation for National Geographic. The Germans used them as stealth aircraft. However, this aircraft could not fly.
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Parked in a hanger. Replicated German invention of 1944 for a documentary by National Geographic. The Northrop Grumman B-2 Spirit (also known as the Stealth Bomber) was replicated from this German aircraft of 1944.

This revolutionary aircraft Horten H. IX was world’s first stealth aircraft that was not allowed to come in lime light till b2 was developed and test flown successfully. It remained closed in the books of history till National Geographic Channel discovered the hidden potential and realised that this aircraft was exactly similar to US stealth bomber B2. Irrespective of the fact that it was an engineering marvel, unparalleled till the advent of B2, it was never allowed to come into lime light for the fear that German technological superiority would be exposed to the world, making rest of the world’s technology look like a dwarf.

Designed by Reimar and Walter Horten and built by Gothaer Waggonfabrik of Munich Germany, the aircraft was named Gotha Go 229. It was a late-World War II entrant as a stealth fighter/bomber. This was also the first pureflying wing” aircraft powered by two jet engines, designed to be difficult to be detect with radar – world’s first aircraft to incorporate stealth technology. This aircraft was a personal favorite of German Air Force Luftwaffe’s chief Reichsmarschall Hermann Göring, and was the only aircraft to come close to meeting his "100/100/100" (Speed/ Range/ Radar detection) performance requirements.

Its speed was estimated at 1,024 km/h (636 mph) and it could cruise at 15,000 meters (49,213 ft), an astonishing statistics for aircraft of 1944.

Design and development

In 1943, Reichsmarschall Göring issued a request for design proposals to produce a bomber that was capable of carrying a 1,000 kg (2,200 lb) load over 1,000 km (620 mi) at 1,000 km/h (620 mph); the so called "3 X 1000 project". Conventional German bombers could reach Allied command centers in Great Britain, but were suffering devastating losses from Allied fighters. At the time, there was no way to meet these goals- the new Junkers Jumbo 004B turbojets could provide the required speed, but was heavy on fuel consumption.

In the early 1930s, the Horten brothers had become interested in the flying wing design as a method of improving the performance of gliders. A wing-only configuration allowed stability without the added drag of the fuselage.

Flying wing layout removed any "unneeded" surfaces and lead to the lowest possible drag. Pitch and yaw movements were controlled by reducing power of on of the engines. This also meant that in the event of failure of one of the engines, the aircraft was difficult to control. However, immediate deployment of undercarriage could make the aircraft stable as the undercarriage side covers provided vertical stability, but reduced speed made it susceptible to enemy attacks from ground as well as air.

In 1942 German Government Air Ministry approved the Horten proposal, but ordered the addition of two 30 mm cannons, as they felt the aircraft would also be useful as a fighter due to its estimated top speed being significantly higher than that of any Allied aircraft.

Construction Materials: Horton H. IX was made of mixed construction materials. Center pod was made from welded steel tubing and wing spars were built from wood. The wings were made from two thin, carbon-impregnated plywood panels glued together with a charcoal and sawdust mixture. The wing had a single main spar, penetrated by the jet engine inlets, and a secondary spar used for attaching the ailerons. It was designed with a 7g capable load factor and had a high safety rating. The wing's chord/thickness ratio of 15% at the root and 8% at the wingtips provided high lift and short take off and landing capabilities.

Control was achieved with ailerons and spoilers. The control system included both long span (inboard) and short span (outboard) spoilers, with the smaller outboard spoilers activated first. This system gave a smoother and more graceful control of yaw than would a single spoiler system.

The aircraft utilized retractable tricycle landing gear. A drag parachute slowed the aircraft upon landing. The pilot sat on an ejection seat.

Operational history

Testing and evaluation: During the final stages of the war, the U.S. military initiated Operation Paperclip, an effort by the various intelligence agencies to capture advanced German weapons research, and keep it out of the hands of advancing Soviet troops. A Horten glider and the Ho 229 V3, which was undergoing final assembly, were secured and sent to Northrop Corporation in the United States for evaluation. Northrop was chosen because of their experience with flying wings, inspired by the Horten brothers' pre-war record-setting glider. Jack Northrop had been building flying wings since the N-1M in 1939.


A Horten H.IV flying wing glider is in the Planes of Fame museum in Chino, California. The only surviving Ho 229 airframe, the V3, is at the Smithsonian National Air and Space Museum's Paul E. Garber Restoration Facility in Suitland, Maryland.

Stealth technology

After the war, Allied commanders were surprised to hear from Reimar Horten that he mixed charcoal dust in with the wood glue to absorb electromagnetic waves (radar), which he believed could shield the aircraft from detection by British early warning ground-based radar known as Chain Home.

A jet-powered flying wing design such as the Horten Ho 229 will have a smaller radar cross-section than conventional contemporary twin-engine aircraft. This is because, with wings blended into the fuselage, there would be no large propeller disks or vertical and horizontal tail surfaces to provide a typical identifiable radar signature. Horten's theories were tested by Northrop-Grumman in 2008 through the building of a replica that was found to give a radar cross section only 40% that of conventional aircraft.

Engineers of the Northrop-Grumman Corporation had long been interested in the Ho 229, and several of them visited the Smithsonian Museum's facility in Silver Hill, Marylandin the early 1980s to study the V3 airframe. A team of engineers from Northrop-Grumman ran electromagnetic tests on the V3's multilayer wooden center-section nose cones. The cones are three-fourths of an inch (19 mm) thick and made up of thin sheets of veneer. The team concluded that there was indeed some form of conducting element in the glue, as the radar signal slowed down considerably as it passed through the cone.

In early 2008, Northrop-Grumman paired up television documentary producer Michael Jorgensen, and the National Geographic Channel to produce a documentary to determine whether the Ho 229 was, in fact, the world's first true "stealth" fighter-bomber. Northrop-Grumman built a full-size reproduction of the V3, (pictured here) incorporating a replica glue mixture in the nose section. After an expenditure of about US$ 250,000 and 2,500 man-hours, Northrop's Ho 229 reproduction was tested at the company's classified radar cross-section (RCS) test range at Tejon, California, where it was placed on a 15-meter (50 ft) articulating pole and exposed to electromagnetic energy sources from various angles, using the same three frequencies used by the Chain Home in the mid-1940s. RCS testing showed that a hypothetical Ho 229 approaching the English coast from France flying at 885 km/h (550 mph) at 15–30 meters (50–100 ft) above the water would have been visible at a distance of 80%.

With testing complete, the reproduction was donated by Northrop-Grumman to the San Diego Air and Space Museum. The television documentary, Hitler's Stealth Fighter(2009), produced by Myth Merchant Films featured the Northrop-Grumman full-scale Ho 229 model as well as reconstructions depicting a fictional wartime scenario where Ho 229s were operational in both offensive and defensive roles.

V S Saxena

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