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Junkers W 33

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W 33
W 33Bremenafter its historic Atlantic crossing.
Role Transport
Manufacturer Junkers
Designer Herman Pohlmann[1]
First flight 17 June 1926[2]
Introduction 1927
Status retired
Produced 1927–34
Number built 199
Variants Junkers W 34
Junkers Ju 46

TheJunkers W 33was a German 1920s single-engine low-wing monoplane transport aircraft that followed Junkers standard practice making extensive use of corrugated aluminium alloy over an aluminium alloy tube frame, that was developed from the similar but slightly smallerJunkers F 13,and evolved into the similarW 34.One example, namedBremen,was the first aircraft to complete the much more difficult east–west non-stop heavier-than-air crossing of the Atlantic.

Design and development[edit]

Like all Junkers designs from theJ 7fighter onwards,[3]it used aduraluminumaluminium alloy structure covered with Junkers' characteristic corrugated dural skin. While the Junkers W 33 was unusual when compared to the contemporary biplanes in use in the UK and the US,cantilevermonoplanes were a popular design choice in continental Europe during the period, and the Junkers designs were unusual only in their extensive use of closely corrugated metal skins. Unlike the skins on the contemporaryRohrbach Roland,those on the Junkers aircraft were not load bearing and it did not have astressed skinstructure. The Junkers W 33 was a direct evolution of the 1919 four-seat airliner, theJunkers F 13.[3]The F 13 was similar to the W 33, but slightly smaller and had some detail differences. Considerable evolution occurred in the structure of the F 13, so that later models shared more details with the W 33. The wings had the same span as the late F 13s, though the planform differed slightly, while the length was the same as the F 13fe.[3]

Cross section of the W33 wing

A slightly different fuselage cross section gave the W 33 a squarer cabin with a hunch-backed appearance compared to that of the F 13 and a door was provided on the port side to provide access to the freight compartment.[3]Early examples of the W 33 had an open cockpit much like the F 13, although it lacked the structural member that divided the pilot and co-pilot, and the corresponding and very distinctivecoamings.Some examples, such as the transatlantic machines had an early enclosed cockpit.

The 228 kW (306 hp)Junkers L5upright inline water-cooled engine was also the same as used in the F 13fe, a more powerful engine than used in many of the F 13 variants. The W 33 differed primarily from the W 34 in normally using an inline engine (aside from the rare dGao variant, which served as a prototype for the W 34), while the W 34 generally used various radial engines and had some minor detail improvements, such as a larger enclosed cockpit.

As was common for the time, when a wheeled undercarriage was fitted, aconventional fixed undercarriagewas used with a tailwheel. Early examples had a similar undercarriage to that used on the F 13, in which a hinged cross axle connected the two main wheels, while later examples provided an independent three-legged structure for each wheel. The JunkersWletter may have denoted the type as a seaplane (forWasserflugzeuge), but in practice W 33s were equipped as either landplanes or seaplanes, as needed.[4]As a floatplane, the W 33 was equipped with two main floats, braced to the fuselage with a forest of struts.

The prototype W 33, registeredD-921,first flew as a seaplane fromLeopoldshafen,on the riverElbenear Dessau on 17 June 1926.[2]Production began in 1927 and ran until 1934 and most of the 198 production machines were built at the Junkers works atDessau,but a small number were assembled at Junker's Swedish subsidiary AB Flygindustri atLimhamnnearMalmö,and atFili,nearMoscowin the USSR.[5]Both of these plants had originally been built to avoid Allied post-war restrictions on aircraft manufacturing in Germany followingWorld War One,that had been considerably eased by the time the W 33 was flying.

In 1934 a Junkers W33 was used to test theJunkers Jumo 210engine. It was flown with a 680 hp version on 5 July 1934.[6]

Operational history[edit]

Transatlantic W 33 on display at Bremen airport
Junkers W 33 first prototypeD-921at theDeutschen Seeflugcompetition, July 1926

Soon after their first flights the first two W 33 prototypes competed at theDeutschen Seeflugseaplane competition atWarnemündein July 1926, with the first prototype W 33 competing as no.7, and coming in second in the contest while the second prototype, a W 33a, competed as no.8.[2]

W 33s were used by many operators across the world in the late 1920s and 1930s,[3]as transports and mailplanes.Deutsche Luft Hansaonly had four that they used for mail from 1929. Others were flown as survey aircraft and crop-sprayers. Later, despite their obsolescence, the Luftwaffe would use some as trainers alongside W 34s.

TheColombian Air Forceused Junkers W 33, W 34 and the militarized W 34, the K 43, during theColombia-Peru Warof 1932–1933.[7]TheEthiopian Air Forceoperated a single W 33c during theSecond Italo-Abyssinian War.

One Junkers W 33g was used by the Swedish Air Force from 1933 to 1935 as an air ambulance under the designationTrp2.This aircraft may have been assembled at Linhamm, as were four W 33s exported to Australia.[8]After World War II, this aircraft was used as a utility transport by the Swedish Air Force'sF 2 Hägernäs squadronand in June 1952, it participated in the search and rescue operation during theCatalina affair,in which two SovietMiG-15sshot down a SwedishDouglas C-47intelligence aircraft and theSearch and RescueConsolidated Catalinasent out after it.[9]

Of the 17 W 33s assembled in Russia at Fili from imported parts at least 9 appeared on that country's civil register.[8][10]In Russian service, they were given the designationPS-3as the thirdPassazhirskii Samolyot(passenger aircraft or airliner), while at least 17 Russian examples were built by GVF workshops with numerous improvements with the designationPS-4.[11]

Flight records[edit]

The Junkers W 33 set numerous records, and one example, named theBremen,made the first east-to-west crossing of the Atlantic by airplane.[3]

The North Atlantic had previously been crossed by theUS NavyCurtiss NC-4flying boat, with numerous stops, and byAlcockandBrownin 1919 in aVickers Vimy,nonstop, and by others, but all of these heavier than air aircraft flew the easier west to east route, which had theprevailing windshelping them along with a tailwind. On April 12–13, 1928, the W 33D-1167 Bremenwas flown byKöhl,von HünefeldandFitzmauricefromBaldonnel, Irelandnear Dublin into the prevailing winds, toGreenly Island,off the coast ofQuebecin theSt. Lawrence River,in 37 hours. Strong winds took them north of their intended destination, which was to have been New York, and they put down near the first settlement they found, but caused minor damage to the aircraft that required some time to repair before they continued. Their aircraft is now on display atBremen Airportin Germany. The Bremen was one of two aircraft making the attempt, however theEuropanever made it out of Germany.

German Stamp commemorating the historic 1928 flight of the W33

A W 33 set class C world records for an endurance flight of 52 hours, 22 minutes and for covering a distance of (4,661 km (2,896 mi)) during a single flight around Dessau between 3 and 5 August 1927, piloted byJohann Riszticsand Edzard. Earlier Fritz Loose and W.N. Schnabele had set another Class C record for duration and distance, while carrying a 500 kg (1,100 lb) load. For that flight they remained aloft for 22 hours 11 minutes and travelled 2,736 km (1,700 mi). At about the same time, the W 33 set a similar pair of records in Class Cbis (Seaplanes).[12]A substantially modified W 33 fitted with a radial engine and so sometimes erroneously referred to as a W 34, flwon byWilly Neuenhofenset an altitude record of 12,740 m (41,800 ft) on 26 May 1929.[3]

The first Swedish-assembled W 33 was completed in May 1930, and delivered two months later to Japan. With Eiichiri Baba flying under the command of Lt. Col. Kiyoshi Honma, and with Tomoyoshi as the radio operator, J-BFUB, namedThird Hochi Japan-USdeparted Sabishiro Beach nearMisawaon 24 September 1932 in an attempt to cross the Pacific Ocean to the US, but they disappeared en route. Their last radio transmission indicated that they were passing to the south ofEtorofu Island.[13]Neither wreckage nor survivors were ever found, despite an extensive search. (see alsoList_of_missing_aircraft#1920–1939)

Accidents and incidents[edit]

Variants[edit]

W33 floatplane
Junkers W 33
-b.-c,-dd and -f powered by a 230 kW (310 hp)Junkers L5water-cooled inline engine.
Junkers W 33
-c3e and -he powered by a 250 kW (340 hp)Junkers L5Gwater-cooled inline engine.
Junkers W 33
-dGao powered by a 400 kW (540 hp)Siemens Sh 20radial engine.
Junkers W 34
A 6-passenger development powered by a variety ofradial engines.[3][16]
Junkers K 43
Bombing and reconnaissance version built in Sweden, equipped for machine guns in the cabin roof and floor.[16]
PS-3
Soviet designation for German built examples.[11]
PS-4
Soviet designation for locally produced modification.[11]
Trp2
Swedish Air Force designation.[16]

Operators[edit]

The W33 Bremen aircraft of the atlantic crossing

Civil operators[edit]

Brazil
Canada
China
Colombia
Germany
Iceland
One on civil register[8]W.33d, "Súlan" (The Gannet)
Japan
Two on civil register.[8]
Sweden
Three on civil register.[8]
Soviet Union
  • Deruluft[5]
  • Dobrolyotoperated 7[5][19]
  • TsARB (Центральная авиационная ремонтная база – Central aviation repair base) operated 10[19]

Military operators[edit]

Colombia
Ethiopia
Germany
Iran
Mongolia
Sweden
Soviet Union

Specifications (Landplane)[edit]

Junkers W 33 'Bremen' 2-view drawing from L'Aérophile May,1928

Data fromJunkers: an aircraft album No.3[3]

General characteristics

  • Crew:Two
  • Capacity:cargo hold volume 15.7 m3(550 cu ft)
  • Length:10.5 m (34 ft 5 in)
  • Wingspan:17.75 m (58 ft 3 in)
  • Height:3.53 m (11 ft 7 in)
  • Wing area:43 m2(460 sq ft)
  • Airfoil:Göttingen 256[21]
  • Empty weight:1,220 kg (2,690 lb)
  • Max takeoff weight:2,500 kg (5,512 lb) *Maximum Load:830 kg (1,830 lb)
  • Powerplant:1 ×Junkers L56-cylinder water-cooled in-line piston engine, 228 kW (306 hp)
  • Propellers:2-bladed fixed-pitch propeller

Performance

  • Maximum speed:180 km/h (110 mph, 97 kn)
  • Cruise speed:150 km/h (93 mph, 81 kn)
  • Range:1,000 km (620 mi, 540 nmi)
  • Service ceiling:4,300 m (14,100 ft)

References[edit]

Citations[edit]

  1. ^Zoeller, Horst."Junkers – Who is Who?".The Hugo Junkers Homepage. Archived from the original on October 27, 2009.Retrieved2016-06-22.{{cite web}}:CS1 maint: unfit URL (link)
  2. ^abcKay, 2004, p. 64
  3. ^abcdefghijklTurner & Nowarra 1971,pp. 39–40
  4. ^Turner & Nowarra 1971,p. 10
  5. ^abcdGunston 1995, p. 131
  6. ^Vajda, Ferenc A.; Dancey, Peter (1998).German Aircraft Industry and Production, 1933-1945.McFarland. p. 234.ISBN978-1-85310-864-8.
  7. ^von Rauch 1984, pp. 3–4.
  8. ^abcde"Registration index".
  9. ^Flight Stories."The Catalina Affair, Part 1 of 3 ‹ HistoricWings:: A Magazine for Aviators, Pilots and Adventurers".Fly.historicwings.Retrieved2022-04-04.
  10. ^Fitzpatrick, Peter."Junkers W33/W34".Archived fromthe originalon 30 September 2018.Retrieved22 June2021.
  11. ^abcAndersson, 1995, p. 161
  12. ^Flight,3 November 1927, p. 763
  13. ^Yukihiro, Torikai (2018)."ユンカースW33 chuyển vận cơ /W34/K43f thủy thượng cơ: Điểu nuôi hành bác phòng nghiên cứu"[Junkers W 33 transport aircraft / W34 / K43f Seaplane: Torikai Yukihiro Laboratory] (in Japanese). Japan.Retrieved22 June2021.
  14. ^Winter, Barbara (1979).Atlantis is missing... a true account. Australia's most bizarre air rescue.Hong Kong: Angus & Robertson Publishers.ISBN0207142335.
  15. ^"Airport News – Croydon".Flight.No. 3 November 1932. p. 1027.
  16. ^abcdeKay, 2004, pp. 72–75
  17. ^Grant, 2004, pp. 70–75.
  18. ^Andersson, 1994, p. 6
  19. ^abcGunston, 1983, p. 127
  20. ^"Abyssinia 1935–1936".Nevington War Museum.
  21. ^Lednicer, David."The Incomplete Guide to Airfoil Usage".m-selig.ae.illinois.edu.Retrieved16 April2019.

Bibliography[edit]

  • Andersson, Lennart (Autumn 1994). "Chinese 'Junks': Junkers Aircraft Exports to China 1925–1940".Air Enthusiast.No. 55. pp. 2–7.ISSN0143-5450.
  • Andersson, Lennart (July 1998). "Histoire de l'aéronautique persane, 1921–1941: La première aviation du Chah d'Iran" [History of the Persian Air Force, 1921–1941: The First Aircraft of the Shah of Iran].Avions: Toute l'aéronautique et son histoire(in French). No. 76. pp. 2–12.ISSN1243-8650.
  • Andersson, Lennart (1995).Soviet aircraft and aviation, 1917–1941.London: Putnam. pp. 159–161.ISBN978-0851778594.
  • Andersson, Lennart (March–April 1999). "Round-Out".Air Enthusiast.No. 80. p. 80.ISSN0143-5450.
  • Andersson, Lennart; Endres, Günter; Mulder, Rob J.M. (2015).Junkers W 33, W 34 and K 43, Workhorse in Peace and War.EAM Books.ISBN978-0957374416.
  • Grant, Robert S. "Metal Marvels: Junkers W 33s and W 34s in the Canadian Bush".Air EnthusiastNo. 110, March/April 2004. pp. 70–75.ISSN0143-5450.
  • Gunston, Bill (1983).Aircraft of the Soviet Union: The Encyclopaedia of Soviet aircraft since 1917.London: Osprey. p. 127.ISBN978-0850454451.
  • Gunston, Bill (1995).The Osprey Encyclopedia of Russian Aircraft 1875–1995.London: Osprey.ISBN1855324059.
  • Hotson, Fred W. (1988).The Bremen.Toronto: Canav Books.ISBN978-0921022022.
  • Kay, Antony (2004).Junkers Aircraft & Engines 1913–1945.London: Putnam Aeronautical. pp. 28–38.ISBN0851779859.
  • Munson, Kenneth (1978).German Aircraft Of World War 2 in colour.Poole, Dorset, UK: Blandford Press.ISBN0-7137-0860-3.
  • Turner, P. St. John; Nowarra, Heinz (1971).Junkers: an aircraft album No. 3.New York: Arco Publishing Inc.ISBN0668025069.
  • von Rauch, Georg. "A South American Air War...The Leticia Conflict".Air EnthusiastNumber 26, December 1984 – March 1985. pp. 1–8.ISSN0143-5450.