Junkers J 9, militärische Bezeichnung D.1

Während des ersten Weltkrieges waren die Produkte der Junkers-Flugzeugwerke nicht gut angesehen bei der IDFLIEG (Inspektion Der Fliegertruppe) und bei der Fliegertruppe, zu sehr war man auf den konventionellen drahtverspannten Holz-Tuch Doppeldecker fixiert. Der Entwicklungssprung zum unverspannten freitragenden Tiefdecker war einfach wohl noch zu groß und zu früh. Wir wissen heute, das diese Ansicht falsch war.

Von Seiten der IDFLIEG  wurde Junkers gedrängt, mit der Firma Fokker in Schwerin zu kooperieren. Und der der umtriebige Anthony Fokker soll danach alles daran gesetzt haben, die Flugzeuge mit der Junkers-Handschrift nach oben "madig" zu machen. Beschämt sei der, der dabei Böses denkt, denn Fokker war ja voll im Geschäft und hatte Praktiken, an Aufträge zu kommen, die im alten Preußen eigentlich zu einem Aufschrei hätten führen müssen. Diese Verbindung wurde im Frühjahr 1919 wieder gelöst.

Kurzum, Junkers hatte keinen leichten Stand, dafür aber vorausschauende Technik. Die J 9 wurde 1918 bei der (neuen) Junkers-Fokker AG aus dem 1917 bei der "alten" Junkers AG entworfenen Versuchsmaschine J 7 entwickelt.j9 5

So ähnlich sahen dann später die die Doppeldecker ablösenden neuen ver-spannungsfreien Eindecker der 30er Jahre aus!j9 5

Es war eine freitragende Ganzmetallkon-struktion aus Aluminium mit einem Rahmen aus Alu-Rohren und einer Alu-         Oben Junkers J7, unten J9 = D.1                                     Wellblech-Beplankung, die noch nicht mittragend war. Sie hatte konventionelle Querruder, dito das Höhenruder, das Seitenruder  war ein Pendelruder, d.h., es war einteilig und besaß keine Dämpfungsfläche.

Sie wurde mit entweder einem wasser-gekühlten 6 Zylinder Daimler-Mercedes Motor mit 136 kW/180Ps oder mit dem neuen entsprechenden, aber aufgela-denen BMW  IIIa Motor mit 137 kW/185 geliefert. Sie nahm an den Konkur-renzfliegen der IDFLIEG 1918 teil und war mit einer Marschgeschwindigkeit von rund 200 km/h sehr schnell. Die damaligen bekannten Flieger des JG 1 Göring und Lörzer wollten mit ihr aber nur eine Fesselballon-Bekämpfung durchgeführt wissen.. Die BMW´s sollen die Höchstgeschwindigkeit sogar auf 240 km/h gebracht haben.

Insgesamt sollen mit Prototypen 41 Maschinen gebaut worden sein. Sie wurden eingesetzt in kleinerer Zahl einmal noch bis zum Waffenstillstand in Flandern und danach in Kurland gegen bolschewistische Truppen in Zusammenarbeit mit deutschen Freikorps, die dort gegen die Bolschewiken kämpften. Es sollen sehr zuverlässige Maschnen gewesen sein.

                     

In der Rückschau ist aber wohl nicht die Militärkarriere wichtig gewesen, sondern der Typ als tatsächlicher Vorläufer des 1918/19 entwickelten ersten reinen Verkehrsflugzeuges, der Junkers F 13. Wir sagen heute nach 100 Jahren, sie sei die Mutter der Verkehrsflugzeuge gewesen, und damit ist die J9/D.1 deren (technische) Großmutter. ! Exemplar hat die Zeiten überlebt und ist in dem wunderbaren Luftfahrtmuseum in Le Bourget zu bewundern. Und dann 

gibt es noch ein 1:1 Modell von Herrn Pflumm für das Luftwaffenmuseum in Gatow, das man aber aus kaum nachzuvollziehenden Gründen nach Rechlin abgegeben hat.

Wir haben 3 Modelle davon im Museum, einmal in 1:72 in den Modellbauvitrinen der Halle 1 und zwei weitere im M:48 in unserer Schnellflugausstellung, wo man die Verbindung zu den späteren Junkerstypen F 13, W 33 und Ju 52 gut besehen kann.

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Junkers J.9/D.1 in 1:72 mit F 13 in der Halle 1

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Die D.I / J9 im Maßstab 1:48 in 2 ver-schiedenen Vitrinen der Halle 2 in der Schnellflugaus-stellung und unten zusammen mit F 13 und W 33 ebenfalls im M 1:48.

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Die Heinkel He 70 Blitz und ihr Umfeld

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Here - because of the immense importance of this story - we have to go back a little in time. The type of aircraft we are talking about here has an exciting pre- and post history.

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At the beginning there were two students (they were called students at that time and for a long time afterwards!) of the Technical University of Hannover, who had dedicated themselves to aerodynamics and aeronautical engineering. During their studies they were still working on projects at the Hamburg aircraft company Bäumer. The most important one was the innovative „Sausewind“ with its elliptically shaped wing plan, designed by the two students, brothers Walter and Siegfried Günter from Thuringia. At that time there were hardly any other wings than rectangular wings, apart from the Junkers F 13 with its trapezoidal wings, which also brought a significant increase in performance.

This new wing geometry resulted in quite a leap in performance: With a 65 hp air-cooled US three-cylinder radial engine Wright Gale and a take-off weight of 490 kg the two-seater „Sausewind“ with its tension-free elliptical wing had a fantastic average speed of a good 180 km/h on long distance flights. The aircraft had been modified and further improved several times.

Paul Bäumer had a fatal accident in Copenhagen in 1927 during the demonstration of the Rohrbach Rofix fighter plane, which meant that the Gü

And here we come to the Heinkel He 70 Blitz at the beginning of the 1930s, after Günter had developed the sports aircraft Heinkel He 64 as a further development of the Sausewind - but with a trapezoidal wing plan - for the 1932 European round flight Competition, piloted by Elly Beinhorn. This aircraft had no more bracing wires or struts. The new lightweight construction, which was increasingly used after the weight restrictions imposed by the allied victors, was also noticeable here and also contributed to the increase in performance (at almost all aircraft manufacturers in Germany).nter brothers lost their jobs. Ernst Heinkel in Rostock had aviation firmly in mind and always wanted "faster - higher - further" and got Siegfried Günter, now gratuated, and brother Walter a little later - without exams.

At that time all airlines were interested in faster aircraft, and technical development made it possible: At the end of the 1920s, the US research institute NACA (today NASA) invented the NACA canopies, which significantly reduced the massive air resistance of the air-cooled radial engines. These canopies were soon used in the Ju 52, Boeing 247 and Douglas DC-2, all of which were launched at that time.

The next step was the introduction of the drag reducing retractable landing gear, which the US company Lockheed with the legendary designer Jack Northrop achieved right at the beginning of the 1930s. Such a retractable landing gear was first introduced in 1919 by the US racing aircraft Dayton-Wright in 1919, but then led a quiet life. During this time - coming from the USA - controllable pitch propellers with constant speed were introduced, again an increase in performance. To reduce the landing speed it was equipped with split flaps.

Lockheed had used a wooden half-shell construction for the small passenger aircraft Vega, similar to the albatross fighters of the 1st World War, first without, then with NACA canopy. With such an aircraft Amelia Earhart was the first woman to fly across the Atlantic (her red Vega can be admired today in the Smithsonian in Washington D/C). The step that followed was a low-wing aircraft of similar dimensions, the Lockheed Orion, also in this wooden construction, but now with retractable landing gear.

The Deutsche Luft Hansa (the name was made into one word later) noticed this, especially since the Swiss Swissair was flirting with the Orion. Ernst Heinkel did not let him rest. He applied to Luft Hansa and Swissair with the new design of the Heinkel He 70 Blitz for this call of tender for a fast medium-haul airliner.

The He 70 was a low-wing aircraft, stress-free, with a fuselage of metal half-shells, with recessed rivets (!) and wooden wings with retractable landing gear. It could carry up to 5 passengers and 1 pilot, and this with a BMW VI

In-line twelve-cylinder engine, water-cooled, with an initial output of 550 kW/700 hp. With this she made a cruise speed of 280 km/h (v/max 360 km/h!).

The transfer of the aerodynamics of the Sausewind with the elliptical wing to this much larger new construction enabeled these performances. The competitor model Lockheed Orion made of wooden half-shells showed similar performances with trapezoidal surfaces, a radial engine from Wright with NACA hood, and 575 HP.

A new path in aviation had been taken, and success was not to be missed. In 1935 Lufthansa operated 10 aircraft in intra-European air traffic. Further examples went to the Luftwaffe and to Spain and Hungary. In 1932-35 the He 70 was faster than the double-decker fighters of the time.

Then the British aircraft engine company Rollce-Royce bought one and equipped it with the then ultra-modern Kestrel aircraft engine, a modern vertical V-12 liquid-cooled high-performance engine with 510 kW/ 695 hp. With this, the He 70 even made 410 km/h v/max and v/travel at 370 km/h. And this He 70 became Supermarine's aerodynamic model for the Spitfire, the British fighter of World War II, designed by its top designer Mitchell.

Above: Ernst Heinkel and Siegried Günter at a drawing board at Heinkel, where the twin brothers Siegfried and Walter Günter made a great aviation career after leaving Bäumer. Walter was killed in an accident in 1937, Siegfried stayed with Heinkel and had to go to the Soviet Union for a few years after the World War. From about 1955 he worked again for Heinkel and the EWR Süd.  Below: The innovative Bäumer Sausewind, aerodynamic model for the Heinkel He 70 and the British Supermarine Spitfire.

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On the left side we see the Supermarine Spitfire Mk. IX, whose aerodynamics corresponded very much to the Mk. I On the right the Heinkel He 112, developed with similar aerodynamics, which lost against the Messerschmitt Bf 109 in the Luftwaffe.

 

Mit dem aus dem Kestrel dann eingeführten RR-Merlin wurde die Spitfire dann ein wesentlicher Hochleistungsjäger der Briten in immer weiter verbesserten Versionen während des gesamten Krieges und später, ähnlich wie die Messerschmitt Bf 109 im Deutschen Reich.

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Modelle im Museum in 1:72: Links Bäumer Sausewind, Mitte He 70 V2, rechts Lockheed Orion. Unten He 70 und Lh Orion

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Up: In 1:48 in der Schnellflugausstellung: Hinten links Lockheed Orion, rechts Lockheed Vega, mittig Bäumer Sausewind, davor die li. Fläche der He 70 V2

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Above in front the Sausewind, on the right the Orion, on the left He 70 V2, above He 70 G-Series - and behind in the shadow the Heinkel He 112. four aircraft from the front on the lower picture in the showcase Schnellflug.

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Below, from the other direction, the Supermarine Spitfire Mk. II in front, to the left behind it the He 112, and in the back the aircraft shown above.

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On this side from the other direction in front the Supermarine Spitfire Mk. II, on the left behind it the unsuccessful He 112, in the back the aircraft shown above.

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And if you would like to visit our museum and see these models "in real": models 1:72 in Hangar One and models 1:48 in Hangar Two in the high-speed flight exhibition - with many data of this and many other aircraft.

Your Museum Team

BFW (Messerschmitt) M 20
(Modell im Maßstab 1:72)

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The models are painted according to the LUFT HANSA design of 1928

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Here we come across a very interesting and far-reaching story: Willy Messerschmitt designed the M 20, the first metal Messerschmitt aircraft from Augsburg. (The M 18, also made of metal, was developed in Bamberg before moving to BFW in Augsburg). All his life Messerschmitt was an advocate for extreme lightweight constructions.

We anticipate something: After several crashes, Erhard Milch, the boss of the former LUFT HANSA, accused him of being more than dubious in his behaviour and his constructions being questioable. This resulted in a feud that lasted well into the war, when the Me 210 flopped and other problems burdened their relationship. In the meantime Milch had become the supreme client of the German aviation industry as chief of the Reichsluftfahrtministerium (Aviation Ministry) - on the other hand Messerschmitt could get along better with the "Führer".

The M 20 was a typical Messerschmitt construction - like the powered gliders and sports aircraft, which were still made of wood: shoulder wing airplanes with trapezoidal wings and box-shaped fuselage. From today's point of view it was a Dornier Merkur with Messerschmitt wings.

The prototype crashed after the tail unit broke at the beginning of 1928 and the pilot was killed. Four planes were sold to the DLH (one to the DVL). In 1930 the next accident with casualties happened in Dresden while landing in bad weather. In April 1931 there was a broken tail unit again. DLH cancelled all orders and did not pay, it was a coffin nail for the BFW.

But here it gets a bit mystical: despite non-payment the DLH used the M 20 again, chartered by DVL (Deutsche Versuchsanstalt für Luftfahrt), which took over the remaining aircraft. Who paid what, when, why and to whom and why the BFW went bankrupt nevertheless, these questions were never answered by the historians.

After that, no other incidents happened during flight operations. One plane went to Colombia and flew there without accidents for a long time. Some of these Lufthansa planes were still in service with the Luftwaffe until 1943 and were then scrapped. In total the DFLH had 14 aircraft (!).We don’t know if the one which went to Columbia is included in this number.

Technical data:

wingspan 25.50 m, length 14.90 m, wing area 65 m², height 3.75 m, empty weight 2600 kg, max. take-off weight 4650 kg, engine 1 x BMW liquid cooled standing in-line engine with 500 HP = approx. 370 kW. v/max 219 km/h, v/cruise 190 km/h, sevice ceiling 5500 m, range 880 km, crew 2 + 10 pax.

FVA (Akaflieg - Aerodynamical Engineering Students Association Aachen)

 

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The FVA was founded by Prof. Kármán and his assistant Wolfgang Klemperer at the RWTH (Technical University) Aachen immediately after the First World War. Until today it serves as a place of applied flight science.

The first successes at the beginning of the 20s were the light gliders "Black Devil" and "Blue Mouse", which founded glider flying on the Rhön Mountains. The development work then faded out there, people were more occupied with practical flying.

The then student Hans Sander, later chief test pilot at Focke-Wulf in Bremen, in cooperation with Karl Dötsch built a glider as a diploma thesis, the FVA 9,  and called it Blue Mouse 2. For the first time wind tunnel research took place. Due to the lack of a pilot, not much became of it. It was the time to turn from slope wind flying to thermal flying.

Based on these experiences, Felix Kracht (later an Airbus executive) built the F.V.A. 10 A Rheinland, which crossed the Alps in 1936. The aim was to reduce the overall drag (closed canopies, greater wing extension, fuselage shape optimisation) and increase the glide ratios.

Around 1935 main developers were Artur Getto and Benno Sann  while the further development F.V.A, 10 B Rheinland was revised by Felix Kracht. He was assisted by the entrepreneur Schmetz, who operated a sewing needle factory. He later became well known in aviation circles when he, Haase and Kensche developed the high-performance HKS 1-3 gliders with which Haase achieved world beating performances at the end of the 1950s.

The 10 B showed all kinds of innovations: The transition between the wings and the fuselage was optimized and the fuselage was already slightly constricted behind the cockpit, as is common today everywhere. In addition, the aerodynamical efficient full-vision cockpit was introduced, so that the hull appeared club-shaped in profile. The  popular gull-like wing design was adopted. Also a retractable landing gear was developed, after a retractable runner did not prove itself.

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The (seagull-) kink-wing was three-parted, its middle part was firmly connected with the fuselage without a gap, reducing drag. The wing was single-armed with a torsion-resistant leading edge (introduced here in Hannover in the year 1920 at the Vampyr). All control elements were ball-bearing-mounted and thus smooth-running. The wing load was about 20 kg/m², the aspect ratio 21.9. These were excellent values which were only surpassed by the world-famous Schleicher Ka 6 in the 1950s. The Rheinland was a top product in its time! Kracht achieved best performances with it in Austria in 1937.

Some successes were achieved in the Rhön and other competitions. And a series production was organized at the company Schmetz. The exact number of airplanes is not known, maybe there were about 29. One flew in GB, one in CSSR, several were flown after the war in Germany by the RAF. One (D-12-354) can be seen today in the Brookland Air Museum/GB.

Technical data:

wingspan 16.00 m, length 7.04 m, wing area 11.70 m², aspect ratio 21.9, empty mass (with parachute) 142 kg, take-off weight 240 kg, payload 98 kg, lowest sink rate 0.60 m/s, glide ratio 1:28

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Focke-Wulf - Small Passenger Aircraft of the 20s

(Modell im Maßstab 1:72)

Henrich Focke and Georg Wulf have been working together on various projects in Bremen since the end of World War II. After the readmission of a (limited) production of aircraft in Germany they founded the Focke-Wulff Flugzeugbau A.G. in January 1924.

The model shows an A 16 of the new LUFT HANSA after 1926

It was a plywood construction with plywood planking, the rear fuselage was fabric-covered. The aerodynamics of the wings were based on the good flight characteristics of the Indonesian pumpkin seed Zanonia, which was also used by Etrich on his „Taube“.

The regulatory authority DVL conducted the type examination and the first plane was operated by the Bremen Seaside Resort Service for flights to the island of Wangerooge, beginning in the  summer of 1924. Later the aircraft was equipped with more powerful engines than the Siemens radial engine Sh7 75 HP / 55.2 kW. This required reinforcements at the wings and the airframe. Altogether 21 planes were built between 1924 and 1926. These planes formed the basis of the later so famous company Focke-Wulf in Bremen, which, after re-foundation in the 50s, became VFW-Focker and then merged with MBB and EADS and finaly became AIRBUS.

In 1988 EADS-AIRBUS in Bremen built a replica, which can be admired in the Berlin Museum of Technology, next to the Arado Ar 96.

Postscript: It is interesting to note that at about the same time the Tupolev design office in the Sojwet Union was designing a very similar plane: the ANT-2 - but this one was made of aluminum sheet metal. 

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This picture: The Russian Tupulew ANT-2, very similar to the Focke-Wulf A 16, but made of aluminum sheet metal in 1924.

 

Technical data:

Length 8.50 m, wing span 13.90 m, wing area 27 m², height 2.30 m, engine 1 x

air-cooled 7-cylinder radial engine Siemens Sh 7 with 75 PS / 55,2 kW

v/max. 136 km/h, range 500 km, basic weight 570 kg, max. take-off weight 970 kg,

Crew 1 + max. 3 passengers.

 

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