Nazi Germany (1938)
Armored Ground Attack Aircraft – 1 Replica Built
Stubo I Replica [aviationmuseum.eu]The Hütter 136 was an interesting concept for a ground attack aircraft that employed numerous experimentations in its design. The cockpit was fully armored, the landing gear was replaced by a skid, and the entire propeller would be jettisoned off during landings. The aircraft came in two forms: the Stubo I, a short design with the ability to carry an external 500 kg bomb, and the Stubo II, a lengthened version that could carry two internal 500 kg bombs. The program never progressed as far as production and work stopped on the project shortly after the Henschel Hs 129 was ordered for production.
History
Artist’s Impression of the Stubo I [Heinz Rodes]During the years leading up to the Second World War, Nazi Germany found itself needing a competent air force to rival those it would soon face. Restrictions set by the Treaty of Versailles severely hindered the German military both in size and equipment in order to ensure that German power would not threaten the continent again, as it did during the First World War. History notes that the Germans broke this treaty, at first covertly and then overtly, with the Allies showing no response or protestation to the blatant violations. Germany began amassing a massive military force in preparation for war. New programs and requirements were laid down in preparation for the inevitable war. These projects included many newly tested concepts, such as dive-bombing. The Junkers Ju-87 Stuka proved the effectiveness of dive bombing in the Spanish-Civil War, with a famous example being the Bombing of Guernica, but a newer attacker was eventually needed to complement it. An order in 1938 was put out by the Reichsluftfahrtministerium (Aviation Ministry, “RLM”) to develop a new armored ground-attacker. One of the companies that would participate in this requirement would be Hütter.
2-way and cutaway of the Stubo II
The designs of Ulrich and Wolfgang Hütter are relatively unheard of when it comes to aircraft. They began their aviation career designing glider aircraft in the 1930s, such as the popular Hü 17, some of which were used post-war. The Hütter brothers built a career in designing aircraft for the Luftwaffe (German Air Force) between 1938 and 1944 under the codename of Ostmark. The two began working on the project mentioned before for an RLM request for a new ground-attacker in 1938. The requirement laid down very specific guidelines to be followed. The new aircraft needed to have good flight performance and an armored airframe for extra protection, as well as enough speed to evade fighters. In preparation for the new designs, the RLM notified designated factories that would begin to produce these airframes upon adoption into service. The Hütter brother’s response would be the Hü 136. Other competitors included the Henschel Hs 129 and the Focke-Wulf Fw 189V-1b, an armored ground attack version of their reconnaissance plane. Not all projects for a new attacker were armored at this time. Other new designs included the Junkers Ju 187 and Henschel Hs P 87.
The Hütter Hü 136 was nicknamed the Stubo, a shortened version of the name Sturzbomber (Dive Bomber). The aircraft itself would be a single-engine design. Two versions of this aircraft existed. The first, Stubo I, was meant to fill the need for a heavily armored attacker and would be used in ground-attack and dive-bombing tactics. The second was the Stubo II, a two-seater which was essentially a longer version of the Stubo I and carried twice the bomb load internally. The flight performance of the Stubo II was estimated to be the same as that of the Stubo I although, given the design characteristics, that estimation is highly doubtful. The two designs did not meet the requirements for bomb load and range. To make the aircraft more efficient, the brothers took an interesting design change. Taking a note from their glider designs, they removed the conventional landing gear and replaced it with an extendable landing skid, which made the aircraft lighter and freed more space for fuel. This, however, posed serious designs problems. The Hü 136 now had to take off using a detachable landing gear dolly, similar to how the Messerschmitt Me 163B rocket plane would take off a couple years later. Due to this, the propeller would not have enough clearing and would hit the ground during landings. To fix this, the two brothers made the propeller detachable. During landings, the aircraft would eject the propeller, which would gently parachute to the ground above an airfield for recovery and reuse. To assist in landings, a new surface brake was also added to the aircraft.
2-way and cutaway of the Stubo I
The far more conventional Henschel Hs 129 would be designated the winner of the competition. Subsequently, no construction was ever started on either the Stubo I or II. The Stubo proved to be an interesting but flawed concept. The limited visibility from the armored cockpit would negatively affect the aircraft in all operations. Dogfighting, bombing and even flying in general would be affected by the cockpit’s design. The change in landing gear design may have extended the range and lowered weight, but pilots now had to learn how to land using a skid. The fact the entire propellor evacuated the aircraft was a huge issue in itself. Once ejected, the landing could not be aborted, and if the landing attempt failed, there was no chance to loop around and try again.
This, however, would not be the last project designed by the Hütter brothers for the Luftwaffe. Wolfgang would begin working on a long-range reconnaissance version of the Heinkel He 219 called the Hütter Hü 211. Another project is the rather unknown Hütter Fernzerstörer (Far Destroyer), a long-range turboprop attacker meant to be used on the Eastern Front. With the war ending, no further Hütter aircraft were designed. One would think the story of the Stubo ends with its cancellation, but the story continued rather surprisingly recently. The Military Aviation Museum in Virginia Beach, VA, acquired a full-scale replica of the Stubo I in 2017 and it is currently on display in their German Experimentals section, along with full-scale replicas of other “Luft 46” designs.
Design
The Stubo I was a single-engine armored ground attacker. In the front, it mounted a detachable propeller and a Daimler-Benz DB 601 inline engine. In the fuselage, a large gap was present between the engine and cockpit. This was most likely the fuel tank where the fuel tank was placed. Beneath the aircraft, a single 1010 Ibs bomb (500 kg) was mounted on an external hardpoint. This hardpoint most likely would be in the way of the landing skid, implying the payload had to be dropped before making an attempt at landing. For takeoff, a dolly would have to be mounted beneath the aircraft. This would be jettisoned shortly after the Stubo would be airborne. For landing, the aircraft would use an extendable skid. The wings of the aircraft had slight dihedral, which meant the wings were angled upward from the body. The Stubo I had an armored steel cockpit that was completely enclosed. For visibility, a small sight in the front and two side portholes were given. Had the aircraft been produced, peripheral vision would have been nonexistent and dogfighting would have been near impossible if it needed to defend itself. Normal operations, such as navigation and landing would have also been hindered, while combat operations such as target acquisition and attack run planning would have been exceedingly difficult. A tailfin was mounted directly behind the cockpit and not in a conventional tail design. Sources also mention the Stubo I would have mounted machine-guns, but the plans do not show exactly where or of what type these would have been.
Artist’s Impression of the Stubo II [Heinz Rodes]The Stubo II was virtually identical to the Stubo I, aside from its extended fuselage. This lengthened design would allow the Stubo II to carry two 1010 Ibs (500 kg) bombs in a bomb bay, compared to the single bomb carried on a hardpoint by the Stubo I. Among smaller differences, the Stubo II’s wings had no dihedral compared to the angled dihedral of the Stubo I. With the lengthened fuselage, the landing skid was also extended to accommodate the longer airframe. It most likely also carried over the machine guns used on the Stubo I. The Stubo II uses nearly identical sized wings to the Stubo I, which gives the Stubo II a rather odd design, having the body lengthened but the wing size remaining the same. This would have definitely affected performance and possibly would have made the aircraft more unstable in maneuvering with the extra weight.
Variants
Stubo I – Armored ground-attacker that would carry a single external 500 kg bomb. Sources also mention machine guns, but documents don’t show where exactly they would have been located.
Stubo II – A lengthened version of the Stubo I, the Stubo II had an internal bomb load of two 500 kg bombs.
Operators
Nazi Germany – If the Hütter 136 would have entered production, Nazi Germany would have been the main operator of the craft.
Hütter 136 “Stubo I” Specifications
Wingspan
21 ft 4 in / 6.5 m
Length
23 ft 7 in / 7.2 m
Height (estimate)
5 ft 3 in / 1.6 m
Engine
1x 1,200 hp (894 kW) DB 601 Inline Engine
Loaded Weight
8,160 lbs / 3,700 kg
Maximum Speed
348 mph / 560 km/h
Range
1,240 mi / 2,000 km
Maximum Service Ceiling
31,170 ft / 9,500 m
Crew
1 pilot
Armament
1x 1010 lbs (500 kg) bomb
At least 2 machine guns of unknown type (Most likely MG 15 or MG 17)
Nazi Germany (1937)
Twin Engined Fighter – 9 Built
The Fw 187 Falke was a twin engine fighter that was built by Focke-Wulf in 1936, at a time when the newly-formed Luftwaffe did not consider such an airplane type necessary. Despite receiving significant negative feedback, several prototypes were built and three pre-production versions were also constructed. The three pre-production types saw limited service defending the Focke-Wulf factory in Bremen against Allied bombing in 1940. Aside from that, they saw no other combat.
History
The first Fw 187 V1 shortly after being completed.
The twin-engined fighter was a concept few countries pursued in the early days of flight. The type only started serious development in the years directly preceding the outbreak of the Second World War, with planes such as the American Lockheed P-38 Lightning entering service. Most officials across the globe agreed that two-engine fighter aircraft would be rendered unnecessary by cheaper and lighter single-engine designs. In the early 1930s, Germany had no plans to develop such an aircraft either.
However, an aeronautical engineer by the name of Kurt Tank showed an interest. Kurt Tank was the main aircraft designer of the Focke-Wulf company, who developed most of the company’s most famous aircraft. During WWII, he would go on to create the iconic Fw 190 and would later have an aircraft designation named after him, with the Ta 152 and Ta 154. He began work on the new twin-engine project, despite there being no current requirement for such an aircraft. Tank had his first chance to reveal his design at a weapons exhibition held at a Henschel plant in 1936. Tank showed off his innovative design, claiming the twin-engine layout would offer a great speed of 348 mph (560 km/h) if the aircraft mounted the newly developed Daimler Benz DB 600 engines. One of the attendants of the event was Adolf Hitler himself, who found the design particularly interesting.
The Fw 187 on jackstands. This photo was taken during testing of the double-wheeled landing gear.
But to the Technischen Amt (Technical Research Office), the design was unnecessary, as it was believed single-engine designs could perform just as well as the twin-engined concept. Another pre-war doctrine was that the current bombers would be fast enough to outrun the fighters of the enemy, and escort fighters wouldn’t be needed. Tank, not happy with this response, took his design to Oberst (Colonel) Wolfram von Richthofen, the head of the Development section of the Technischen Amt. Tank persuaded him that technological advances would eventually allow the construction of more powerful fighters that would be able to catch up with the bombers which would thus require an escort fighter. Convinced by his claim, Richthofen agreed that it would be better to have a countermeasure now rather than later. Richthofen’s term as chief was short, but in this time he authorized three prototypes of Tank’s twin-engine design. The design was officially given the name of Fw 187.
Work began on the Fw 187 soon after, but, to Tank’s dismay, the requests for the DB 600 engine were turned down. Instead, he had to work with Junkers Jumo 210 engines, as DB 600s were only allocated to projects which were viewed as being highly important. The design work was handed over to Oberingenieur (Chief Engineer) Rudi Blaser, who was the one of the most experienced members onboard Focke-Wulf. Blaser had previously headed the design of the failed Fw 159 monoplane fighter, but he was ready to continue work and move on from his failure. Blaser wanted to achieve only one thing with this design: maximum speed.
The Fw 187 V2 on a test flight.
The first prototype Fw 187 was completed in early 1937. The Fw 187 V1 (designated D-AANA) was first flown by test pilot Hans Sander. In the initial flights, the aircraft reached speeds of up to 326 mph (524 km/h). The Luftwaffe was surprised to learn that despite weighing twice as much as the Bf 109, the Fw 187 was still able to go 50 mph (80 km/h) faster. They accused the team of having faulty instruments. Blaser was determined to prove them wrong and had a Pitot tube (a device that measures air speed using the total air pressure) installed on the nose of the V1, which would accurately tell the performance. Sander once again flew and confirmed the aircraft indeed had attained such a speed. Further flight trials showed the aircraft had superb maneuverability, climbing and diving. These great characteristics led Kurt Tank to name the aircraft his “Falke” or Falcon. This name became official as well, and wasn’t just a nickname the creator gave to his creation.
In the summer of 1937, the airframe had an impressive wing loading of 30.72 Ibs/sq ft (147.7 kg/m2), something no other fighter could equal at that point. Further tests by Sander put the airframe to the extremes to try the limitations of the aircraft in diving. The rudder, during dives, was predicted to begin fluttering after 620 mph (1000 km/h), but Blaser was more cautious, and thought it would start at a lower speed. To counteract this, a balance weight was attached to the rudder. Blaser assured Sander that the aircraft would perform better in dives as long as he didn’t exceed 460 mph (740 km/h). With the new weight attached, Sander took off to begin trials. Hitting 455 mph (730 km/h), Sander noticed the tail had begun violently shaking. With the tail not responding, Sander had started to bail when he reported a loud noise came from the rear. Sander’s control over the aircraft had returned and all vibrations had ceased. Upon landing, it was found that the weight itself had been the culprit of the vibrations and the sound Sander heard was the weight breaking off the rudder.
An aft view of the V6. The surface cooling system is visible in this shot.
Several modifications were made to the V1 during testing. The frontal landing gear was switched out for a dual wheeled design at some point, but was found it offered no benefit over the single wheel and thus was reverted. The propellers were also changed from Junkers-Hamilton to VDM built ones. Weapons were eventually added as well, but these were just two 7.92mm MG 17s. The 2nd prototype arrived in the summer of 1937. Visually, the V2 was identical to the V1, but had a smaller tailwheel, modified control surfaces, and Jumo 210G engines with enhanced fixed radiators.
However, in 1936, there was a change of leadership in the Technischen Amt. The supportive Richthofen was replaced by Ernst Udet. Udet was a fighter pilot, and his experience reflected upon his decisions. He made sure no more biplane designs were being built and all designs were now of monoplane construction. He had a major focus on fighters, and believed them to be the future. The modern fighter had to be efficient, with speed and maneuverability being the utmost importance. And, from this viewpoint, he saw twin engine fighters as not being as capable as single engine fighters. With this mindset, the Luftwaffe now saw no real reason to continue developing the Fw 187 as a single seat interceptor, but it could be developed as a Zerstörer (“Destroyer” heavy fighter), the same role the Bf 110 occupied. This required a crew of more than one and much heavier armament. Tank was reluctant, and felt his design was still as capable as single engine designs were, but he knew continuing to go against the Technischen Amt would result in his aircraft being terminated, so he regretfully obliged.
The V3 was in the middle of construction and changes had to be made as a result of this. The V1 and V2 had already been produced, and any drastic changes would further affect development, so no attempt to convert the two initial planes into two-seaters ever occured. To accommodate a radioman, the cockpit had to be lengthened. This worried Blaser, who was concerned these changes would affect the size and overall performance of the aircraft. Thus, he tried making the changes that affected the aircraft’s performance as little as possible. The fuselage was increased lengthwise, the tailfin was shortened, and increased cockpit volume demanded the fuel tank be moved farther back. Engine nacelles were also shortened to allow installation of landing flaps for when the aircraft carried larger ordnance. The 7.92mms were now complemented with two 20mm MG FF cannons, although V3 never mounted any actual weapons, only mock-ups.
The Fw 187 had good luck up until this point, but this good fortune ran out shortly after the V3 was produced. A few weeks after it was finished in early 1938, the V3 was doing a test flight when one of its engines caught on fire. The aircraft was able to safely land and the fire was extinguished, but the airframe had taken some damage and needed repairs. Tragedy struck once again not too long after, on May 14th. The V1 was lost and its pilot, Bauer, was killed during a landing accident. These two events happening so close together made the already negatively viewed Falke seem not only an unnecessary weapon, but now an unreliable one as well. Two more prototypes were built late in 1938, the V4 (D-OSNP) and V5 (D-OTGN). These two were mostly identical to the V3, but had several slight modifications, such as a modified windshield. Judging by photos, one obvious trait V4 and V5 had over V3 is the lack of the radio mast mounted on the cockpit of the V3. V4 and V5 were sent to the Echlin Erprobungsstelle, a major aircraft development and testing airfield for the RLM (Reichsluftfahrtministerium, German Ministry of Aviation). The trials at this site yielded favorable evaluations of the aircraft and three pre-production examples were ordered.
One of the A-0s flying overhead.
While all of this was going on, Tank was finally able to acquire two DB 600A engines for his Falke. The plane that mounted these engines would be the V6. Before the V6 was built, Tank had shown interest in surface evaporation cooling, a drag reducing novelty which had been researched and developed by Heinkel and was soon to be worked on by Messerschmitt. With the V6 now under construction, Tank drew plans to apply the feature into the prototype to give it peak performance. V6 (CI+NY) first flew in early 1939 and showed how well the new engines and surface cooling made the aircraft perform. On takeoff, the V6 had 1,000 HP from each engine, a 43% boost over the previously used Jumo 210s. During one test flight, the V6 was flying 395 mph (635 km/h) in level flight.
The three pre-production examples previously mentioned were designated Fw 197A-0. These were were fully armed. The A-0s added armored glass to the windshield and carried two more MG 17s. The A-0 planes also returned to using the Jumo 210 engines. Due to the additional weight, the performance of the A-0s was a bit lower than the prototypes. However, the RLM continued to argue against the Falke, claiming that, because it had no defensive armament, the Fw wouldn’t be as effective as the Bf 110 in the same role (despite it being able to outperform the 110 performance-wise). The final decision related to the Falke was an idea to turn it into a night-fighter in 1943. Nothing ever came out of this proposal.
The Factory Defender
Although the Bf 110 seemingly took the Falke’s place, its story continued. As the Royal Air Force (RAF) began its attacks over mainland Germany in 1940, aircraft firms scrambled to defend their valuable factories. Several firms formed a “Industrie Schutzstaffel”, which was an aerial defence program which would have aircraft company’s factories and testing sites be defended by aircraft piloted by test pilots and to be managed by on-site personnel. Focke-Wulf was one such firm and, luckily for them, three fully operational Fw187A-0s were ready and waiting to be used in combat. These examples were sent to the Focke-Wulf factory at Bremen and were sent on numerous missions to defend the plant from Allied bombing. Allegedly, Dipl.-Ing (Engineer’s degree) Melhorn claimed several kills while flying one of these aircraft. After the stint in Bremen, the three were put back into armament and equipment testing. In the winter of 1940 to early 1941, the three were sent to a Jagdstaffel unit in Norway, where they were evaluated by pilots. One of the three was sent to Værløse, Denmark in the summer of 1942 and temporarily assigned to Luftschiess-Schule. It is likely the remaining 3 and prototypes were either scrapped or destroyed by Allied bombing, as no examples are known to have survived the war. Some sources claim the aircraft Melhorn flew was the V6 converted into a single seater and armed for combat, but no proof supports this.
The Fw 187 was no secret weapon. After the fighting in France died down, the Propaganda Ministry began producing film and photos of the Fw 187 in 1940-1941 to persuade the Allies into thinking the Falke was fully operational and replacing the Bf 110 as the Luftwaffe’s all new Zerstörer. In reality, the latter was taking over the role of the former. The campaign sort of worked, as the Fw 187 was now a part of the rogue’s gallery that the Allies expected to fight. Identification cards, models and even movies were made to train pilots in the event they should encounter the two engine terror in combat. One such film denotes that the Fw 187 is “a rare bird” and that they should comically “make it extinct”. This shows that the Allies didn’t completely fall for the propaganda that claimed it was being produced in mass quantity.
Design
The Fw 187 had a twin engine design. The airframe was of all light metal construction. To reduce drag, the airframe was actually narrower at its widest point than other fighters of the time. The wings were of metal construction and divided into three sections. The connected segments carried the fuel and the outer segments had the flaps installed. The first and second prototypes had a single seat cockpit. The cockpit was covered by a canopy that slid aft. The cockpit itself wasn’t built for comfort, as it was built for an average sized pilot. The cramped cockpit lacked the necessary space to mount certain instruments and had these mounted outside on the engine cowlings. V1 had tail sitting landing gear, with all three wheels being able to retract into the hull. V2 was similar to V1, but had modified control surfaces. Beginning after the first two, all examples of the Fw 187 had an extended greenhouse cockpit to accommodate the radioman. The cockpit now opened up in two sections, one to the front and one to the rear. The fuselage was lengthened to some degree as well. The extended cockpit required the fuel tank to be moved down the fuselage. The engine nacelles were shortened to allow landing flaps to be added. V3 also had a radio mast mounted on the rear part of the cockpit. V4 and V5 had this removed.
For engines, the majority of the Falke’s used the Jumo 210 engine. V1 mounted the 210Da, V2-V5 using the 210G, V6 using the powerful DB 600A engines and the A-0 reverting back to 210Gs. The aircraft performance stayed the same overall, with the V6 having peak performance speedwise.
For armament, V1 mounted two MG 17 machine guns. V3 had accommodations for two more MG FF cannons but only mockups were added. When the A-0s were rolled out, an additional two MG 17s were added to fill the Zerstorer role. The extra two had their ammunition mounted in front of the radioman’s seat.
Variants
Fw 187 V1 – First prototype. Mounted two Junkers Jumo 210Da engines. Originally mounted Junkers-Hamilton propellers but was changed to VDM airscrews. Originally had two wheeled forward landing gear which was switched to single during development. Fitted with two MG 17 machine guns.
Fw 187 V2 – Second prototype, had different rudders and a semi-retractable tail-wheel. Had fuel-injection Jumo 210G engines.
Fw 187 V3 – Third prototype. Two seat version, the cockpit was lengthened to accommodate the radioman. The engine nacelles were shortened some degree to allow new landing flaps.V-3 also mounted two MG 17 machine guns and two MG FF cannons.
Fw 187 V4/Fw 187 V5 – Fourth and fifth prototypes. Nearly identical to V-3, aside from several small modifications, such as having different windscreens.
Fw 187 V-6 – Sixth prototype. High speed version that mounted Daimler Benz DB 600A engines.
Fw 187A-0 – Pre-production version. Three were constructed. Armed with two MG FF cannons and four MG 17 machine guns. Frontal armored windshields were added. These three were tested and sent to various locations for trial and defensive purposes.
Operators
Nazi Germany – The sole operator was Nazi Germany, which reportedly used the Falke during the air defense of Bremen in 1940.
Fw 187V2 – The second single-seat prototype with a large curved canopyFw 187V3 – Two seat cockpit and canopy design were established along with new engines and nacellesFw 187V4 – Curved windscreen was fitted, however this change would not lastFw 187V5 – Two more MG-17 added below the canopyFw 187A-0 – The A series was the first and only production batchThe V5 on standby. A visual difference between the V3 and the V4/V5 is the absence of a radio mast mounted on the cockpit.Side view of the V6.A period 3-way illustration of the Fw 187 A-0The Fw 187 V3 after it’s engine fire. Notice it’s greenhouse cockpit and the way it opens.A cockpit view of one of the A-0s. Note the glass floor.The V4 taking off. The V4 and V5 were slightly modified versions of the V3.Three pre-production Fw 187 A-0s on standby.An aft view of the V6. The surface cooling system is visible in this shot.
Nazi Germany (1942)
Light Transport and Trainer – 1,216 Built
The Siebel Si 204 was a twin engined light transport and trainer aircraft built by Siebel for the Luftwaffe in World War II.
History
Si204s under construction
The story of the “Siebel” factory starts in the 1934, with the founding of “Hans Klemm – Flugzeugwerke Halle“ that was a branch of “Leichtflugzeugbau Klemmin Böblingen”. In December 1937 the name changed to “Siebel Flugzeugwerke“ when it was taken over by Friedrich Siebel.
Initially Siebel had a license to produce the Focke-Wulf Fw 44 “Stieglitz” and later during the war Heinkel He 46, Dornier Do 17 and the Junkers Ju-88. In addition to the production of licensed aircraft, in 1937, “Siebel” produced its own aircraft under the name Fh 104. It had its first test flight that same year, and some 46 planes where build during the period of 1938-42. The Fh 104 made a number of notewortly flights:
In March of 1939 flying a 39975 km tour of Africa,
Winning the “Littorio rally in Italy”,
And flying a 6200 km across 12 countries in 1938 (Europa Rundflug).
Color photo of Luftwaffe Si204
By the end of 1930, “Siebel” company was commissioned by the Luftwaffe to design a new type of all-metal twin-light light transport aircraft with a capacity of eight persons with two crew members. In 1940 the first prototype of the twin engine and larger and also heavier Si 204 appeared with originally a conventional stepped cockpit and a powerplant of two 360 hp (268 kW) Argus As 410 engines . The prototype made its first flight during the period of May to September 1940. Second prototype made it first test flight in early 1941. The third prototype was re-designed as a trainer aircraft for blind flying. Because of this, its first test flight was only possible at the end of 1941 or the beginning of 1942. The other 12 planes produced by “Siebel” were used for general flight evaluation. After this small production run Siebel stopped building this aircraft, and future planes would be built in France and Czechoslovakia.
Model A was build in relatively small number by the French “SNCAC” (Société Nationale de Constructions Aéronautiques du Nord) factory. It was designed as a transport and communication aircraft.
Si204A
The next model D appeared in 1942, with a new glazed nose and cockpit with no separate flat windscreen for the pilot. Almost all German bomber aircraft during the war shared this design. The D model also had more powerful 600 hp As 411 engines. The D model was used for radio navigation and for training. This model was mostly used during the war.
The production of the D-3 version start in October 1944 by the “Aero” company. The D-3 had wooden wings and a tail-plane made of wood because due to material shortages. In France, production of this aircraft was stopped in August 1944 as a result of the Liberation.
“BMM” produced the aircraft until October 1944 and then changed to producing spare parts for the Si 204. The “Aero” was scheduled to cease production of the D-1 in March 1945 after building 486 aircraft and then switch to D-3 only. The E version was built in limited numbers and can be considered as an experimental series.
After the war, production of Si 204 continued in Czechoslovakia and France. Czechoslovakia produced some 179 Si 204D, developed into military trainer variants Aero C-3A, passenger variant C-103 and military transport variant D-44. France produced 240 transport NC.701 Martinets and a number of passenger NC.702 Martinets.
Si204 in French Service
Operational history
Si204D Armed Version
During the war the Luftwaffe put the plane to use for transport, communication while also seeing use as an advanced trainer and blind flying trainer.
It was generally regarded as a good plane, but with some drawbacks like the lack of any armament, which prevented many exercises for the combat training program and possible use as a combat aircraft, although for this role it is not designed.
Designers in Halle had developed few different military projects, like installing bomb racks, machine gun turrets and other necessary equipment, but none of these plans were ever realized. This problem was attempted to be solved with some modified Si 204D airplanes with three 13mm MG 131 machine guns, intended to be used as a night combat aircraft but this model was not used in combat and was built in limited numbers.
Despite these unsuccessful attempts, Germans tried to make a new bomber variant, in order to be used in anti guerrilla fighting with a built to this specification. Three Si-204E were sent to the military tests in Belarus. They were treated as special anti-guerrilla aircraft. The scope of the actions of the Belarusian partisans forced the Germans to throw against them not only regular troops, but armored vehicles and aircraft. The extent to which they were used in this role remains unknown.
Si 204 is reported to has the “honor”, of being the last German aircraft shot down on the Western Front. On May 8, 1945 an Si 204 was shot down by an American P-38 Lightning, three miles southeast of Rodach, Bavaria.
Production variants
Closeup of Si204 Engine Nacelle
Because Siebel produced the Junkers Ju-88 under licence and the need for as many military aircraft as possible, Germans decided to increase the volume of production for this aircraft. This was done by moving the production to French “SNCAC” and Czechoslovakian “Aero”, and “ČKD-BMM” factories. The “SNCAC” produced some 168 aircraft and the “Aero” and “ČKD-BMM” produced 1033 aircraft, Siebel produced only the first 15 prototype Aircraft, before the production was stop in favor of Ju-88. In total some 1,216 aircraft of this type where build, during the war.
During WW2
Si 204 – Prototype version with 15 plane build by Siebel (Number V1 to V15),
Si 204A – Model A was a transport and a communication aircraft, with crew of two and eight passengers.
A-0 – Passenger plane version,
A-1 – French built version.
Si 204B and C – Were paper projects
Si 204D – Model with a new glazed nose and cockpit and with two 600 hp As 411 engines. Model D was used for radio navigation and for flying training.
D-0 – Blind flying trainer,
D-1 – Czechoslovakian production version,
D-3 – This model had wooden wings and tailplanes, in order to save on metal.
204E – Experimental night fighter plane. This model had on its nose two 13mm MG 131 machine guns plus one more machine gun (same caliber) in a glazed cupola on the upper hull of the plane. This model was not used in combat and was build in limited number using rebuild Si 204D planes.
E-3 – Proposed version to be armed with bombs, and to be used in anty guerrilla fighting, possibly only few were build.
Flying carrier – Paper project that was originally intended to carry one DM-1 (Doctor Alexander Lippisch plane) on the back of a Siebel Si 204. Little is known about this project
Postwar
Czechoslovakia Version:
Aero C-3 – Used for flying and crew training,
Aero C-103 – Used for Civilian transport,
Aero D-44 – Military transport version.
France versions:
SNCAC NC.701 Martinet – Military transport version with SNECMA 12S-00 air-cooled V-12 engines,
SNCAC NC.702 Martinet – Improved Passenger transport version.
Operators
Germany – Most produced planes where used by the Luftwaffe as advanced schools training, transport, blind flying trainer (usage in this role was at best was sporadic) and communication. There were plans for arming this plane for night fighter and anti-partisan operatons, but it all left on paper only with few model build and not a single one was used in combat.
Czechoslovakia – Used German build planes and the new Aero C-3 version after the war.
France – Used some captured German planes and also the NC. 701 version which was build by France after the war.
Hungary – Operated some C-3 Aero version after the war.
Poland – Used six NC.701 version.
Soviet Union –They were captured in some numbers at the end of the war. At first, the captured Si-204 was mostly used by the military. The headquarters of many regiments and divisions stationed in Germany used the Siebel for official flights, but only for short period.
Sweden – Operated five NC.701 (1962-1970) for mapping photography.
Switzerland – Operated some Si.204 D planes.
Specifications (Si 204D)
Wingspan
70 ft / 21.33 m
Length
39 ft 3 in / 12 m
Height
14 ft / 4.25 m
Wing Area
495 ft² / 46 m²
Engine
2x Two Argus As 411 12 cylinder inverted piston engines (447kW/600 hp)
Nazi Germany (1938)
Nazi Germany (1942)
