Hans von Ohain

Frank Whittle (left), Hans von Ohain (right)

Dr Hans von Ohain (pictured here to the right, with Frank Whittle to the left) has a claim to be the first person to conceive of a serious way of making a workable gas turbine jet engine. A common opinion at the time appeared to be that gas turbines would be too heavy.

By 1935 he had patented the concept, and actually developed a test engine which was made for him by Max Hahn in Göttingen - the S1 (Strahltriebwerk 1).

He approached Heinkel for assistance.

Heinkel

Heinkel proved to be extremely enthusiastic, and offered Ohain enormous support. He started work at Heinkel's base (along with Hahn) in Marienehe, near Rostock, in June 1936 and Heinkel announced he wanted a ground test by June 1937, lead on by Ohain's original estimates (which, not surprisingly, proved to be overly optomistic).

As a stopgap, sometime around the end of February 1937, the He S-1 engine was tested using hydrogen fuel (an impractical fuel for a real engine) and produced a thrust of about 110 kilos at 10,000 rpm. This engine used a centrigugal compressor. Von Ohain reported: "The apparatus fully met expectations. It reached the anticipated performance, it handled well in acceleration and deceleration, probably because of the relatively small moment of inertia of the compressor and turbine rotor and the great stability of the hydrogen combustion over the wide operational range".

Work progressed on building a combustion chamber capable of withstanding the extremely high temperatures that would be encountered in a real engine (the original engine run appears to have convinced Heinkel and Ohain's standing within the company rose).

Von Ohain's team had a working bench-test prototype, the He S-3 (running with petrol), in September 1937, six months after Whittle had reached the same benchmark.

In 1938, the engine was strapped to an He-118 dive bomber (a prototype of a type which had lost out to the Stuka) for evaluation. By mid 1939, the He S3B was delivering 500 kgs of thrust - tests began in May 1939 and continued until the engine burned itself out a few months later. Enough had been learned to build a pure jet-powered experimental aircraft, the "Heinkel He-178", powered by an improved He S3B engine with kilograms thrust.

Heinkel H178

At 4 in the morning of 27. August 1939, the world's first jet aircraft - the Heinkel He-178, took off, flown by Erich Warsitz. At the time, the project was still officially a secret, even from the German authorities. Warsitz flew for about 10 minutes, and reached 600 ? km/hr at a height less than 1000 meters. A telephone call to Ernst Udet, the head of equipment at Air Ministry apparently received a less than enthusiastic response.

War broke out a few days later. Heinkel received orders to cease work on research and development, but he decided to keep going, financing the project himself. This apparent lack of foresight on the part of the Air Ministry could possibly be explained by a belief in the war being a short affair.

Later in the flight test program, the He-178 would be fitted with a further improved "He S6" turbojet with 590 kilograms thrust.

Heinkel 178

On 1. November, independent representatives of the Air Ministry flew it.

Despite these innovations, the Nazis were apparently unimpressed and give no support to the project.

After a total of about a dozen test flights, the He-178 was sent to the national air museum in Berlin, where it was destroyed in a bombing raid in 1943. A second He-178 was planned, but not completed.

Heinkel 178 - translation of an article from Flug Revue.

Heinkel He 280

Heinkel, despite official disinterest, pressed ahead with a design for an operational jet fighter. This was the twin-engined He 280 which first flew on March 30 1941 and reached in excess of 800 km/h.
Warsitz, Heinkel, von Ohain

E

June 1939, Mueller and a half of his original workforce worked on 006, an advances axial flow engine.

Von Ohain continued working on a centrifugal flow engine - S6 and the 0011.

designers working on He 280 for new engine. Ohain's S6 was still disappointing in the He 178, decided to replace with He 280. Lusser was put in charge of the He 280.

He S8 or 001 Mueller He S30 or 006

In 1940 received a contract for the He 280. In September 1940, one airframe was complete. 11 September 1940 onwards, tested in gliding flight (mostly by Paul Bader). 2 April 1941, preliminary test flight with underpowered 001 engines. Demonstration in front of top brass four days later (by Paul Bader).

He 280 January 1942, pilot escaped by ejector seat, believed to be the first use of such a device.

006 Mueller transferred to the former Hirth works in Stuutgart. A bench test takes place in the spring of 1942.

1942 onwards, orders of Schelp, development of the 001 under Ohain is stopped. Mueller had left company in May 1942. Schelp told him to drop work and concentrate on the 011, which was regarded as extremely important for the future Luftwaffe.

Which was a mistake because apparently it was giving a vastly improved performance over the Junkers 004, which Schelp refused to believe (end 42). But it never flew except in a Ju88 testbed.

This ironically doomed the He 280 because it had to use the heavier 004 engine.

On 27 March 1943, Heinkel was ordered to abandon the He 280 project.

011 taken out of Heinkel's hands and placed under RLM control

RLM, Reich Luft Ministerium (Reich Air Ministry)

Despite official lack-of-recognition of Ohain's work, other bodies within the Reichsministry appears to have been simultaneously supporting work on jet design.

Hans A. Mauch had become head of rocket development at the RLM in April 1938, and quickly expanded his office's charter to emphasize turbojet development, working with an experimental department under Helmut Schelp in the RLM development division.

Mauch had actually viewed the partially completed Ohain engine and the He 178 in mid 1938. He had also sponsored work on ramjets and pulse jets. But Mauch and Schelp actually spurned aircraft manufacturers like Heinkel and Junkers and decided to concentrate on the four main engine manufacturers - Daimler Benz, BMW, Junkers Aero-Engines and Bramo. By mid-1938, the two men had set up a comprehensive program of jet engine development that was soon sponsoring a range of turbojet and turboprop projects.

Daimler Benz had refused to join the program, Mader of the Junker Engine Company was given a small project (he still did not know of Wagner's work), BMW small-scale project. Bramo of Berlin were more enthusiastic because they feared being squeezed out of the piston-engine market by rationalization.

Professor Betz of Göttingen, joined by Helmut Schelp on the application of jet propulsion to fighter aircraft.

Official engine sequence (preceeded by 109

  • 1 Heinkel (He S8)
  • 2 Bramo
  • 3 Bramo
  • 4 Junkers
  • 5
  • 6 Heinkel
  • 7 BMW (turboprop)

Despite the official attitude of the RLM towards aircraft manufacturers, mentioned above, Heinkel managed to receive contracts for engines by scheming to make use of his friendship with Ernst Udet.

At the end of 1939, Mauch left, leaving Schelp with enhanced authority.

Junkers Aircraft Company

The Junkers Aircraft company (i.e. not the Junkers Engine company, which was actually a separate company until merger in 1936) had actually been working on turbine propulsion (actually a turboprop) since 1936. By 1937 they had decided on a pure jet and were running a bench prototype of an axial-flow turbojet in 1938. Head of this section was Herbert Wagner, and his assistant was Max Adolf Mueller. Their work was secret apart from Heinrich Koppenberg, the head of Junkers. The research took place in Magdeburg (separate from the engine division in Dessau).

Mueller left the company after RLM (??) and he and about half of his workforce went to Heinkel. Most of the rest went elsewhere, i.e. left Junkers.

Junkers Engine Company

In the summer of 1939, the Reich Air Ministry awarded the Junkers Engine Company a contract to develop a simple, powerful axial-flow engine that could be put into production as quickly as possible.

Otto Mader

A design team under Dr. Anselm Franz conducted the development work on the engine, at Dessau, the engine being known as the "109-004" and later the "Jumo-004". They considered the work done by Mueller in Magdeburg (Mueller had just gone to Heinkel), but Franz decided to start his project more or less anew, as opposed to relying too much on developing Mueller's work. This engine became the only German engine to see sustained service with the Luftwaffe. Junkers Jumo 004 Jet Engine

The design was complete by Spring 1940 and a full-scale bench-test engine was possible on November 11 1940. By August 1941, the full thrust had been achieved.

The engine is considered to be quite conservative - Franz was interested in getting a working engine up and running rather than including too many innovations.

It had an 8-stage compressor, six-chamber combustor, and a single-stage turbine. The compressor blade design was by Encke at Güttingen University, and the turbine blades came from AEG Berlin. The weight of the initial version was 750 kgs with a thrust of about 900kg. Its length was 3.9 meters and diameter 75 cms. One important innovation that was included was afterburning.

The first production engine was delivered in June 1943, by which time 500 people were working on the project.

On 18 July 1942, it powered the Me262 Version 2.

6000 were produced by the end of the war.

After the war, Franz became a Vice-President of Avco Lycoming in America. He continued to express admiration of Hitler, and hung a picture of himself with Hitler in a prominent position in his home.

BMW (including Bramo)

In response to urging by the Air Ministry, the Bramo company began work on a pair of axial flow engines. Bruno Bruckmann, Hermann Oestrich.

Both Whittle's and von Ohain's engines were centrifugal flow engines, with a turbine like a pump impeller compressing air into combustion chambers ringing the engine. An axial-flow engine, in contrast, is much more like the turbine of a steam plant or naval vessel, with rings of "fans" driving air directly through the engine.

The two Bramo engines included one with a contra-rotating fan assembly to reduce torque, which eventually was designated the "109-002", and a simpler engine without the contra-rotating fan scheme that was eventually designated the "109-003". Incidentally, the "109-" suffix was used by the RLM to specify turbine engine projects.

Bramo's works at Spandau were bought out by the BMW concern in mid-1939. BMW had been working on their own centrifugal-flow turbojet, but the company quickly decided to abandon their own effort and focus on the two Bramo engines obtained in the buyout. The 109-002 proved too complicated and never flew, and the project was abandoned in 1942. The company focused on the simpler 109-003, with fabrication beginning in 1939 and first test runs in 1940. By that time, the engine was known as the "BMW-003". although problems, development and progress delayed.

München Helmut Sachse Kurt Loehner 2 stage centrifugal

Hans Rosskopf chief designer 003A December 1942.

January 1944 800 kg

3500 at 500 kg for the He 162A

018 started 1941, but the works were overrun just as it was being tested.

Messerschmitt 262

In autumn 1938 the RLM placed an order with Messerschmidt for a jet fighter. A design team originally under Robert Lusser (who soon went to Heinkel) and later Dr. Waldemar Voigt drew up plans for this fighter, with twin turbojet engines. This "Projekt 1065" formed the proposal submitted to the RLM in May 1940.

They knew the plane needed to stay in the air for an hour, at a top speed of 850 km/h.

The engines were mounted in nacelles under the middle of the wings. The wings were slightly swept to ensure proper center of gravity, and had an unusually thin chord, or ratio of thickness to width, for good high-speed performance. As the wing's features for high-speed performance compromised low-speed handling, a "slat" was added to the front of the outer wings. The slat was automatically extended to improve handling at low speeds. The fuselage had a triangular cross section (to allow the undercarriage to retract into it (rather then the wings) and substantial fuel capacity to feed the thirsty engines. The aircraft was a "tailsitter", with fully retractable landing gear.

In July 1940, the RLM ordered three prototypes, to be powered by BMW-003 engines. Messerschmitt 262

First Flight

Airframe development far outpaced engine development, and so the first prototype, the "Me-262-V1" ("V" standing for "Versuchs" or "Experimental"), was fitted with a single Jumo-210G piston engine of 710 horsepower in the nose and a two-bladed propeller for preliminary test flights. First flight was on 18 April 1941. The RLM was becoming more interested in the aircraft, ordering five more prototypes in July 1941.

Flown with BMWs

In November 1941, the Me-262-V1 was finally fitted with a pair of BMW-003 turbojets, each with 550 kilograms thrust, The Jumo 210G piston engine was retained, which was fortunate, since the turbojet engines were hopelessly unreliable and of lower power than expected. On 25 March 1942, Messerschmitt test pilot Fritz Wendel took off from Augsburg and suffered immediate failures of both engines. He managed to make a go-round on the piston engine and land, damaging the aircraft but suffering no injury himself. Messserschmidt (left), Wendel (right) test pilot

Flown with Jumos

Development of the BMW-003 engine was progressing more slowly than expected, while work on the Junkers Jumo-004 seemed more promising, and so the third prototype, the V3, was fitted with two Jumo-004A pre-production engines with 840 kilograms thrust each.

Fritz Wendel took the V3 into the air on 18 July 1942 and found the aircraft extremely impressive. On it's second flight it reached 3 600 meters and a speed of over 700 km/h, faster than any allied planes (It later reached 900 km/h, allowing it to outfly anything). Unfortunately, the V3 prototype was lost a few weeks later - on 17 August while being flown by an official test RLM pilot.

The Me-262V-2 prototype, also powered by Jumo-004As, was not delivered until 2 October 1942. Despite all the delays and problems, the RLM had already ordered 15 preproduction Me-262s in May 1942, and added 15 more to the order in October 1942.

At the time, the Air Ministry was undecided at going ahead with production of the the Me-262 or the "Me-209", an improved version of the piston-powered Messerschmitt Bf-109 fighter. The head of the RLM, Erhard Milch, was conservative and favored the Me-209 over the much more radical Me-262.

However, in the spring of 1943 the tide began to shift towards the jet fighter. The Luftwaffe General of Fighters, Adolf Galland, flew the recently-delivered V4 prototype in April, and a month later on 22 May 1943. He enthusiastically endorsed the type and suggested that the Me-209 be cancelled. A few days later, the RLM placed an order for 100 production Me-262s.

Apparently even this decision did not clear away all the bureaucratic obstacles. Willi Messerschmitt kept on lobbying to produce both the Me-209 and the Me-262, partly it seems as a ploy in bureaucratic empire-building, and it wasn't until November 1943 that the Me-209 was dropped for good.

Even then, the Me-262's political troubles were far from over, and in fact were just about to take a very nasty turn. Hitler, alarmed by the success of Allied amphibious landings in Africa and Italy, was very concerned about developing a fast fighter-bomber ("Jagdbomber" or "Jabo") to pin down invasion forces on the beaches until reinforcements could arrive to drive them back into the sea.

On 2 November 1943, Hermann Goering, head of the Luftwaffe, and Milch visited the Messerschmitt plant in Augsburg. Goering asked Willi Messerschmitt if the new jet fighter could carry bombs. Messerschmitt answered hesitatingly that the Me-262 had been designed from the outset to carry 500 kilograms of bombs. In reality, he does not seem to have considered this possibility.

Major production but still not really ready.

Milch, on reading intelligence reports that the Americans were getting ready to field new bombers such as the Boeing B-29 that would be a handful for existing interceptors, also pressed on with production of the Me-262 as a fighter. Though Milch made agreeable noises about building it as a fighter-bomber, little or nothing was done to that end.

Early in 1944, all pre-production versions were being tested. Production was proceededing faster then production of engines. Apart from that, aircraft pilots were barely ready for conflict.

Pilots were given 4 half-days of lessons before their first solo flight.Landing was a problem, couldn’t reduce speed.

10 days ex drafted in. 200 pilots were killed in training.

Luftwaffe

It was delivered to the Luftwaffe in 1944. The Allies became fully aware of it on July 25 1944, when a photo-reconnaissance Mosquito encountered one over München, the Mosquito escaping into cloud.

Late 1944, the 262 was having a devastating effect. The Allies slowly learnt to deal with them. They could put their Mustangs into a dive, and the 262 could not respond as quick in turns as the propellor aircraft. During take-off and landing, allied aircraft laid in wait (during take-offthe 262 did not have enough speed, during landing they had to reduce)

Every 20th. to be built as a fighter. By late 1944, all were being built as fighters. Early 1945 imperative to build aircraft 800 in forests, but not enough trained pilots. - production ground to a halt.

Of the 1,430 produced only about 300 were operational before the end of the war. Of these, 120 were shot down by Allied fighters.

Wrongly blamed by Göring for the declining Luftwaffe fortunes, Galland was removed from his post but was later allowed to form his own Me 262 jet fighter squadron, Jagdverband 44, and finished the war as he began it - as a fighter pilot. This squadron flew from München from 31. March 1945, and from 26 April was flying from the Augsburg - M¨nchen autobahn.

It was equipped with four 30 mm cannon, and 80 shells, later given rockets. Its maximum speed was 870 km/hr at 6000 meters, to which it could climb in 7 minutes. It had a range of 800 kms. Each engine was rated at 900 kgs. thrust.

Arado Ar 234B-2

Arado Ar 234

The world's first jet bomber which first flew on 15th June, 1943.

The B1 reconnaissance version appeared in the middle of 1944. The B2 reconnaissance bomber appeared later. It had a maximum speed of 740 km at 6000 meters, and had a range of just over a 1000 kms with a full bomb load (1,800 kms otherwise). It was 12.6 m long with a wingspan of 14.1 m. Armament was two 20 mm cannons and it could carry 1,500 kg of bombs. The early version carried the pilot only and was powered by Jumo 004 engines.

The Arado AR 234B arrived too late to make an impact on the course of the war. Its reconnaissance work included spying on airfields over South-East England and France. As a bomber, it took part in the Ardennes offensive, and the attacks on Remagen Bridge.

Around two hundred were built and only 38 of them saw action before the end of the war.

A four-engined BMW 003 variant was planned, capable of 870 km/hr at 12.800 meters. An experimental version was captured on the ground by the British, the wing shape being similar to the wing on the later British bomber, the Handley Page Victor.

Heinkel He 162A Volksjäger

Heinkel 162

Single-seat, land-based bomber destroyer (A-1) and air superiority fighter (A-2)

The result of a desperate Air Ministry directive for a 'cheap' jet fighter, made of cheaper materials (e.g. wood - compare with the British Vampire), and basic even to the extent of (supposedly) allowing it to be flown by pilots whose only prior experience had been on gliders (for example, Hitler Youth). This reflects the dire condition of German air resources at this period of the war. The numbering as the '162' was an attempt to fool the Allies into thinking that the plane had been in development for longer than it actually had.

The project was opposed vehemently by Adolf Galland.

Program launched 8. September 1944, with submissions to be returned on the 14th. of the same month !

The requirements were :- a single-seat fighter, powered by a single BMW 003 turbojet engine with 800kg thrust. The aircraft was to weigh no more than two metric tonnes, considerably less than most fighters of the era. The maximum speed had to be at least 750km/h at sea level, and its endurance had to be at least a half hour at the same altitude. The takeoff run was to be no more than 500 meters. making it possible for the plane to operate from "backwoods" airfields, and it was to be armed with either one or two MK108 cannon.

The contract was originally awarded to the Blohm und Voss P.211.02. However, after some further wheeling and dealing, the contract was eventually awarded to Heinkel.

The Heinkel submission won the contract, but it should be noted that this was a modified design of an project that Heinkel had been working on for a few months - the Heinkel's P.1073 "Spatz". As a result of Heinkel's protests another evaluation ws held on the 19. Septemeber - but the contract was re-affirmed as being awarded to Blohm and Voss.

Two versions were planned, the 162A-1 with 30mm MK108's, and the 162A-2 with the 20mm MG151/20's (the fact that Heinkel's original submission had MG151 cannon instead of MK108 had been a major factor in the project being originally unsuccessful).

The project itself was given the name Salamader, although some sources apply this name also to the aircraft.

It made its first flight 3 months later, on 6th December, 1944, from the Schwechat factory airbase near Wien (Vienna), piloted by Gotthold Peter. The flight lasted 20 minutes until one of the gear doors fell off when the glue came undone during the high speed portions of the flight Otherwise, the flight appeared to have been successful. It had reached a top speed of 840 km/hour at an altitude of 6000 meters.

Four days later on a demonstration flight before government officials, the same aircraft, piloted by Peter, crashed when one of its wooden wings disintegrated. The cause was found to be weak bonding between wooden components. Changes were made to strengthen the wing and when the fourth prototype flew on January 16 1945, the various changes resulted in the He 162 weighing quite a bit more than the two tonne limit, this V4 prototype weighed 2800kg fully loaded. However, the speed of the plane was considerably better than expected, the He 162 was capable of an astonishing 890km/h at sea level and 905km/h at 5950 meters, making it the fastest plane in the world.

300 were built but very few saw action before the end of the war. (By the end of hostilities on 8 May 1945, 120 He 162s had been delivered with a further 200 completed and awaiting collection or flight testing). Only one version had been produced before the war ended, the He 162 A. It had two sub-variants, the A-1, armed with two 30mm MK108 cannon, and A-2, replacing these with high-velocity MG 151 20mm cannon. Further, there was a lack of trained pilots and so only two fighter units, I./JG 1 and II./JG 1 managed to convert to the type before the end of hostilities.

On 4 May 1945 one Gruppe of three squadrons, with a total of 50 aircraft was formed at Leck in Schleswig-Holstein, but British forces occupied the air field on 8 May and accepted the unit's surrender.

The He 162 did actually contain an ejector seat (the placing of the engine meant that a conventional bale-out was impossible) and on 20 April 1945, the first and only successful use of this device (in an He162) was made by pilot Rudolf Schmitt. This was still a risky procedure because of the engine directly behind the cockpit.

Shortly after, on 4 May, the same Rudolf Schmitt shot down a Hawker Tempest (Typhoon?). The fact that the novice German pilot had been able to shoot down one of the RAF's best fighter pilots shows the Heinkel's formidable combat potential.

Only half an hour endurance.

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