Junkers J 1
Junkers J 1 | |
---|---|
The Junkers J.1 Blechesel | |
Role | experimental/Pioneer aircraft |
Manufacturer | Junkers & Co |
First flight | 12 December 1915 |
Retired | 1916 |
Status | Retired |
Primary user | Luftstreitkräfte |
Produced | 1915 |
Number built | 1 |
The Junkers J 1, nicknamed the Blechesel (Tin Donkey or Sheet Metal Donkey), was an experimental
The J 1 originated from the work of pioneering aeronautical designer
On 12 December 1915, the aircraft made its brief maiden flight, flown by Leutnant Theodor Mallinckrodt of Flieger-Ersatz-Abteilung 1 (FEA 1), during which an altitude of almost 3 m (9.8 ft) was reached. Greater altitudes and performance were achieved during subsequent flights. By the end of January 1916, Junkers had been given a contract to further develop his all-metal concept and the later Junkers J 2 single-seat fighter, which would never see front line service, followed the J 1. It is believed that the Junkers J 1 was not flown again after January 1916. In 1926, it was placed on static display at the Deutsches Museum in Munich. In December 1944, the J 1 was destroyed during an Allied bombing raid on the city.
Development
Background
Amongst the earlier pioneers and innovators in the field of aviation was the German engineer and
In 1907 Reissner approached Junkers, seeking his collaboration in the design and construction of an early
During 1910 Junkers received a grant for the construction of a wind tunnel at his research facilities in Aachen; this led to the initiation of an aerodynamic research programme that would, five years later, contribute to the design of the Junkers J 1. In 1911, Junkers resigned his professorship to dedicate his efforts to his Dessau-based engine company; he returned to Aachen upon the completion of the wind tunnel. It was not until 1915 that Junkers was able to fully devote his time to the design and manufacture of an aircraft; it was at this point that he opened a research institute, the Forschungsanstalt Professor Junkers, which was assigned responsibility for the design and development of a series of fully cantilevered all-metal monoplanes.[1]
Upon the outbreak of the
Concept and contract
Junkers and the Forschungsanstalt, commenced engineering work to realize his concept for the creation of aircraft designs that would dispense with
]On 8 June 1915, Junkers began to acquire the tooling for the J 1. According to aviation author Hugh Cowin, while it has often mis-reported as having been produced to a specification forr an aircraft intended for military service, the J 1 was instead intended to be produced purely as a research aircraft, that would lead to the production of a later line of all-metal monoplane fighter aircraft. On 12 December 1915, the J 1 made a short flight at Dessau and was then sent to the Army proving ground at Döberitz for testing, where it made the first real flight on 18 January 1916.[3]
Design
The Junkers J 1 was an experimental mid-wing monoplane that incorporated various modern features, having a
The basic structure of the J 1 was built up around its center fuselage section and the integral inboard stub wing, functioning as the aircraft's wing roots. The stub wings served as attachment points for Junkers' patented spar-less wings, which consisted of short span truss-tires sections successively layered outwards from the stub wings. Other elements fixed onto the centre section include the nose section, rear fuselage, and tail unit. Atypically for the era, the wing lacked any exterior bracing struts or wires; the only use of external bracing was for support of the horizontal stabilisers and the undercarriage. The internal structure made use of welded strip-steel angle stock and I-beam sections in conjunction with portions of steel tubing to form its main internal structure.[5]
The innovative cantilever structure for the wings were also covered in
The 90 kW (120 hp)
Operational history
Flight testing
Before the Junkers J 1 could fly, IdFlieg, the Inspektorat der Fliegertruppen, the aviation administration arm of the German Army, required that static load tests be performed on the J 1. This involved the usual static loading trials being carried out on the J 1's structure using
On 12 December 1915, Leutnant Theodor Mallinckrodt of FEA 1 was assigned to taxi and briefly "hop" the J 1, which he managed to do up to almost a 3 m (9.8 ft) altitude.[5] During the course of this small flight, a gust of wind caught the starboard wing during the "hop" as the J 1 descended, resulting in the port wing tip scraping the ground and the port side of the J 1's fuselage was correspondingly bent inwards towards the rear of the wing mount. Testing was delayed while repairs were made through the holiday period at the end of 1915, after which a further round of static load tests were carried out to test the repairs.[citation needed]
On 18 January 1916, the second flight for the J 1 was carried out at Döberitz by Gefreiter (Private) Paul Arnold of the FEA 1 unit. The J 1 attained an altitude of only 80 m (260 ft), following a 200 m (660 ft) take-off run, as the variable incidence stabilizer had been incorrectly set in the mistaken belief that the J 1 was tail-heavy. Later that day, after the stabilizer was adjusted to give level flight trim, Leutnant Mallinckrodt performed another attempt, this time reaching a maximum height of 900 m (3,000 ft) from a shorter take-off run. Handling was determined to be acceptable and the aircraft was reportedly stable during flight.[citation needed]
On 19 January, Mallinckrodt once again took the J 1 up for its only known "high performance" flight test, which consisted of a 7 km (4.3 mi) course and covered altitudes from 200–300 m (660–980 ft). During this flight, Mallinckrodt reached top speed of 170 km/h (110 mph). As a consequence of military interest in Junkers' design, the J 1 was compared to the popular Rumpler C.I two-seat, armed observation biplane during flight testing. The J 1 was 30 km/h (19 mph) faster, even though the Rumpler biplane was powered by the more powerful Mercedes D.III engine. Given the lighter weight of the Rumpler's wood-and-fabric airframe, it was capable of a much greater rate of climb rate than the J 1, handicapped by its experimental steel structure.[5]
Analysis
The flight performance of the J 1 were evaluated during the test programme.[5] Information was gathered from the pilots and the ground crew that serviced it. Apparently, the welded construction of the aircraft had problems on the ground that had been encountered before. In conjunction with its sluggish performance in the air, some individuals mocked the J 1 with derogatory names, the most prominent of these being the Blechesel (Tin Donkey or Sheet Metal Donkey). Some figures, such as the Dutch aviation pioneer, Anthony Fokker, praised the potential of the aircraft and the principles demonstrated, pointing to the higher speed and greater durability of prospective aircraft using such construction.[5] The handling of the J 1 was the subject of derision by Junkers' critics but the military remained supportive of refinement of the concept. By the end of January 1916, Junkers had been given a contract and the Junkers J 2 single-seat fighter followed, which would never see front line service. The J 2 bore a superficial similarity to the J 1, being more aerodynamically refined and slightly smaller, yet the two aircraft had similar structures.[5]
Preservation and recreations
It is believed that the Junkers J 1 was not flown again after January 1916. The aircraft survived the First World War, and was placed on static display in 1926 at the
Specifications
Data from Wagner and Nowarra (1971). German Combat Planes: A Comprehensive Survey and History of the Development of German Military Aircraft from 1914 to 1945.[8]
General characteristics
- Crew: one
- Length: 8.64 m (28 ft 4 in)
- Wingspan: 12.92 m (42 ft 5 in)
- Height: 3.11 m (10 ft 2 in)
- Wing area: 24.34 m2 (262.0 sq ft)
- Empty weight: 920 kg (2,028 lb)
- Gross weight: 1,080 kg (2,381 lb)
- Powerplant: 1 × Mercedes D.II 6-cyl. water-cooled in-line piston engine, 90 kW (120 hp)
Performance
- Maximum speed: 170 km/h (110 mph, 92 kn)
References
Citations
- ^ a b c d e Cowin 1967, p. 3.
- ^ Byers 2016, p. 15.
- ^ Cowin 1967, pp. 3–4; Grosz 1992, p. 3.
- ^ Cowin 1967, pp. 3–4.
- ^ a b c d e f g h i Cowin 1967, p. 4.
- ^ "Junkers J1 - recreating the world's first all metal aircraft." Kickstarter, Retrieved: 8 October 2017.
- ^ "J 1 Project." J1-project.com, Retrieved: 8 October 2017.
- ^ Wagner & Nowarra 1971.
- ^ Zuerl 1941, p. 55.
Bibliography
- Byers, Richard (2016). Flying Man: Hugo Junkers and the Dream of Aviation. Centennial of Flight (No. 20) (1st (e-book) ed.). College Station: Texas A&M University Press. ISBN 978-1-62349-465-0.
- Cowin, Hugh (1967). The Junkers Monoplanes. Aircraft Profile No. 187. Leatherhead: Profile Publications. OCLC 918137376.
- Grosz, Peter (1992). Junkers D.1. Windsock Data File (No. 33). Berkhamsted: Albatros Productions. ISBN 0-948414-41-3.
- Wagner, Ray; Nowarra, Heinz (1971). German Combat Planes: A Comprehensive Survey and History of the Development of German Military Aircraft from 1914 to 1945. New York: Doubleday. OCLC 161860.
- Zuerl, Walter (1941). Deutsche Flugzeugkonstrukteure [German Aircraft Designers]. München: Curt Pechstein Verlag. OCLC 78530878.
Further reading
- Grosz, Peter; Terry, Gerard (1984). "The Way to the World's First All-Metal Fighter". Air Enthusiast Twenty-Five: 60–63. ISSN 0143-5450.
- Owers, Colin A. (2018). Junkers Aircraft of WWI: Junkers J.1–J.4: A Centennial Perspective on Great War Airplanes. Great War Aviation Centennial Series No. 30. Vol. I. Reno Nev: Aeronaut Books. ISBN 978-1-935881-65-0.