The Junkers firm's early aircraft were identified by the letter J for Junkers followed by an Arabic type number. From 1919 they introduced an additional sales designation using the same number but prefixed by a letter indicating the role of the aircraft:
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G = Großflugzeug (large aircraft),
H = aircraft built at Junkers' Moscow plant,
K = Kampfflugzeug (bomber),
S = Spezial (special),
T = Schulflugzeug (trainer aircraft),
W = Wasserflugzeug (seaplane).
Just once, the same number was used to identify two different completed types. This pair was the T 23 and G 23, both also known as J 23.
During World War I, machines in service used the regular Idflieg aircraft designation system to specify their design's purpose, also promoted by the Flugzeugmeisterei (Air Ministry), again a letter number system indicating role:
CL = two-seat ground attack,
D = single-seat biplane scout, by 1918 used for all single seat scouts,
E = single-seat monoplane scout,
J = two-seat armoured close support biplane.
The best known and most confusing example is the Junkers J 4 armored-fuselage, all-metal sesquiplane, known to the military as the Junkers J.I.
The single letter company prefix was not replaced by the twin-letter Ju prefix until 1933. This RLM system – from the Third Reich's air ministry – applied to all German manufacturers; the first Junkers aircraft to receive a Ju number was the W 33, so retrospectively it became the Ju 33. However, earlier aircraft built in Moscow like the H 21 were often described by a Ju number, e.g. Ju 21.
Junkers J 1, (no military designation) world's first-ever full metal-structure aircraft, 1915.
Junkers J 2, (no military designation) experimental all-metal single seater, designed as fighter, 1916.
Junkers J 3, mid-wing monoplane, cancelled before completion, first proposed corrugated-skin duralumin design.
Junkers J 4, (military J.I) armored-fuselage sesquiplane full metal close support aircraft, 1917
Junkers J 5, unbuilt monoplane scout with engine behind pilot.
Junkers J 6, unbuilt parasol monoplane scout.
Junkers J 7, prototype for J 9, 1917.
Junkers J 8, twin-seat development of J 7, 1917.
Junkers J 9, (military D.I) all-duralumin single-seat fighter, built in J.9/I and J.9/II (lengthened wingspan and rear fuselage) versions, 1918.
Junkers J 10, (military CL.I) all-duralumin monoplane close support aircraft, 1918.
Junkers J 11, (navy C3MG, military CLS.I) floatplane version of J 10, 1918.
Junkers J 12, prototype four-seat airliner developed from the J 10, precursor of F.13, 1919.
Junkers F 13, passenger plane, 1919 originally J 13, sold as Junkers–Larsen in US, 1919.
Junkers JG1, large monoplane project, 1921.
Junkers J 15, precursor of J/K 16, 1920
Junkers K 16, small single-engined passenger plane, alternatively known as J 16, 1922.
Junkers J 17, improved K 16, not built.
Junkers J 18, navy survey aircraft, not built.
Junkers T 19, trainer and tourer, alternately known as J 19, 1922.
Junkers A 20, light transport, 1923.
Junkers J 21, also known as T 21 and H 21, reconnaissance aircraft for Red Army built in Russia, 1923.
Junkers J 22, also known as H 22, for Red Army, fighter similar to J 21, 1922.
Junkers T 23, sports mono- or biplane, 1923.
Junkers G 23, 3-engined 10-seat airliner, 1923.
Junkers G 24, enlarged G 23, 1925.
Junkers F 24, single-engined development of G 23, 1928.
Junkers A 25, A 20s re-engined with Junkers L2 engines, 1926.
Junkers T 26, training and sports aircraft, 1925.
Junkers T 27, a re-engined T 26, 1925.
Junkers J 28, two-seat version of T.21, not built.
Junkers J 29, sports monoplane, double wing development aircraft, 1925.
Junkers K 30, military version of G 24, 1930.
Junkers G 31, 15 seat airliner, 1926.
Junkers A 32, experimental monoplane, 1926.
Junkers W 33, single-engined light transport, (developed from F.13) 1926.
Junkers W 34, single-engine light transport + reconnaissance (development of W33), 1933.
Junkers A 35, postal, training and military aircraft, 1926.
Junkers S 36, twin-engined mail plane, 1927.
Junkers K 37, military version of S 36, 1928.
Junkers G.38, four-engined commercial transport, world's largest landplane when built, 1929.
Junkers K 39, experimental reconnaissance-bomber (development of A 32), 1927.
Junkers J 40, prototype large flying boat airliner (G.38 derived), 1926.
Junkers W 41, an F 24 re-engined with a Junkers Fo 4 diesel engine, 1928.
Junkers R 42, designation for Swedish built K 30s.
Junkers K 43, reconnaissance monoplane, 1927.
Junkers J 44, prototype replacement for A 35, 1927.
Junkers K 45, a single Ju 52 converted to a torpedo bomber, 1932.
Junkers Ju 46, catapult mailplane derived from W 34.
Junkers K 47, close support aircraft, prototype of K 48, 1927.
Junkers A 48, production dive bomber, 1928.
Junkers Ju 49, high altitude research aircraft, 1931.
Junkers A50, sports monoplane, 1929.
Junkers K 51, Ki-20 heavy bomber for Japan, c. 1934.
Junkers Ju 52, single-engined precursor to Ju 52/3m, 1930
Junkers Ju 52/3m Tante Ju (Auntie Ju), passenger airliner and freighter, used as transport + bomber during World War II, 1932.
Junkers K 53, designation for Swedish built A 35's.
Junkers J 54, prototype replacement for A 35, 1929.
Junkers J 56, prototype replacement for K 16, 1930.
Junkers J 58, prototype replacement for F 13 & W 34, 1929.
Junkers Ju 60, low wing high speed airliner, 1932.
Junkers K 85, proposed torpedo bomber version of Ju 86 for Sweden, 1933.
Junkers Ju 85, prototype twin-engined bomber similar to Ju 86, not built.
Junkers Ju 86, twin-engined airliner, bomber + reconnaissance, 1934.
Junkers Ju 87, Stuka, dive-bomber, 1935.
Junkers Ju 88, bomber + reconnaissance + night-fighter.
Junkers Ju 89, heavy transport, heavy bomber (prototype), 1936.
Junkers Ju 90, four-engined airliner, transport developed from Ju 89, 1937.
Junkers Ju 160, low wing high speed airliner developed from Ju 60, 1934.
Junkers Ju 186, four-engined high-altitude prototype version of Ju 86, not built.
Junkers Ju 187, close support aircraft project, cancelled after mock-up built.
Junkers Ju 188, Rächer, bomber, 1941.
Junkers Ju 248, re-designation of Me 263.
Junkers Ju 252, transport developed from the EF 77, 1941.
Junkers Ju 268, parasite bomber project, 1944.
Junkers Ju 286, six-engined high-altitude version of Ju 86, not built.
Junkers Ju 287, prototype jet-engined bomber with swept forward wings, 1945.
Junkers Ju 288, bomber (prototype), 1941.
Junkers Ju 290, transport, patrol, 1941.
Junkers Ju 322, Mammut (Mammoth), transport glider (prototype), 1941.
Junkers Ju 352, Herkules (Hercules), transport, 1944.
Junkers Ju 388, Störtebeker, reconnaissance + night-fighter, 1943.
Junkers Ju 390, six-engine long-range Amerikabomber competitor (prototype) developed from Ju 290, 1943.
Junkers Ju 452, derivative of Ju 252 in wooden construction
Junkers Ju 488, proposed heavy bomber design.
Junkers J.1000, large flying-wing airliner, 1924.
Experimental
Junkers EFo 008, four-engine high-altitude jet bomber
Junkers EFo 009, Hubjäger (Lift-Fighter), jet fighter project
Junkers EFo 010, two underwing-mounted jet engines; record aircraft design
Junkers EFo 011, twin-engine jet fighter
Junkers EFo 012, four-engine jet bomber
Junkers EFo 015, similar to EFo 008, modified nose section
Junkers EFo 017, twin-engine jet fighter (similar to Me 262)
Junkers EFo 018, four-engine jet bomber, engines under wing
Junkers EFo 019, twin-engine jet bomber, engines integrated into wing
Junkers EFo 021, 40-passenger double-deck trans-Atlantic airliner project, 1938.
Junkers EFo 022, record aircraft developed from the EFo 018
Junkers EF 017, single-engine, three seat military aircraft, later A 32 and K 39
Junkers EF 024, single-engine fighter, later A 48
Junkers EF 029, high-altitude aircraft, later Ju 49
Junkers EF 030, single-engine airliner, later W 41 (and possibly Ju 52)
Junkers EF 031, twin-seat sport aircraft, later A 50
Junkers EF 034, four-seat traveling aircraft, Luftlimousine (flying limousine), 1929.
Junkers EF 037, twin-engine military aircraft, 1930.
Junkers EF 043, wind tunnel test model
Junkers EF 048, twin-engine multipurpose military aircraft, K 37 development, 1933.
Junkers EF 049, twin engine airliner, further development of Ju 52/1m, 1933.
Junkers EF 050, VTOL design study, similar to the Fa 269
Junkers EF 052, AFI design study of K 85
Junkers EF 053, early design of EF 100
Junkers EF 055, Ju 287 design study
Junkers EF 056, Ju 287 design study
Junkers EF 057, Ju 287 design study
Junkers EF 058, Ju 287 design study
Junkers EF 059, Ju 88 design study
JUnkers EF 060, early design for EF 127/EF 128.
Junkers EF 061, high-altitude fighter + reconnaissance (prototype), 1936.
Junkers EF 062, early EF 128 design study
Junkers EF 063, early EF 128 design study
Junkers EF 065, possible early EF 082 design study, 1939.
Junkers EF 066, Ju 287 design study
Junkers EF 067, Ju 287 design study
Junkers EF 068, Ju 287 design study
Junkers EF 071, aerodynamic wing tip test model
Junkers EF 072, early EF 077 design study
Junkers EF 073, Ju 288 design study
Junkers EF 077, Ju 252 design study
Junkers EF 082, combat battle aircraft project.
Junkers EF 094, design designation for Ju 322.
Junkers EF 100, six-engine, wide-body transatlantic airliner, 1940
Junkers EF 101, Mistel aircraft design
Junkers EF 112, twin-boom ground attack aircraft project, 1942.
Junkers EF 115, bomber project with four Jumo 211 engines at front and rear or 2 jet engines at rear
Junkers EF 116, W-wing jet bomber project, 1943.
Junkers EF 122, four engine Ju 287 design study, later Ju 287
Junkers EF 125, two engine Ju 287 design study, later EF 140
Junkers EF 126 Lilli, 1944 pulsejet fighter project, completed post-war in the USSR.
Junkers EF 127 Walli, rocket powered version of EF 126.
Junkers EF 128, jet-engine interceptor project
Junkers EF 130, four-engine flying wing jet bomber project, 1943.
Junkers EF 131, six-engine development of Ju 287, completed post-war in USSR.
Junkers EF 132, heavy bomber, partly built in USSR but not completed.
Junkers EF 133, nothing known; probably not used
Junkers EF 134, nothing known; probably not used
Junkers EF 135, development of EF 130
Junkers EF 136, nothing known; probably not used
Junkers EF 137, jet fighter design (according to CIA report), 1943
Junkers EF 138, nothing known; probably not used
Junkers EF 139, nothing known; probably not used
Designations used exclusively in the Soviet Union
Junkers EF 140, twin-engine jet bomber, development of EF 131; completed post-war in USSR.
Junkers EF 145, possibly a Ju 88 or Ju 388 testbed at OKB-1
Junkers EF 150, twin-engine jet bomber, further development of EF 140; largely Russian designed and completed post-war in USSR.
Aircraft engines
All Junkers diesel engines were two stroke, opposed piston designs, an arrangement he invented in the early 1890s. It was intended to provide an alternative to Nicholaus Otto's patented four stroke which would run on low grade fuels such as blast furnace waste gases. By 1896 Junkers engines were generating electrical power in steelworks.
Junkers Fo2, horizontal, petrol, c.1923.
Junkers L1, petrol, c. 1924.
Junkers L2, petrol, 1925.
Junkers L5, enlarged L 2, petrol, 1925.
Junkers Fo3, diesel, 1926.
Junkers L55, "double L5" (V12), petrol, 1927
Junkers L7, small version of L2, petrol; not flown.
Junkers Fo4, diesel, commercially called the Junkers SL1, 1928.
Junkers L8, petrol, geared, higher power development of L5, 1929.
Junkers L88, "double L8" (V12), petrol.
Jumo 204, development of the SL1, initially referred to as the Jumo 4, 1930.
Jumo 205, diesel, reduced displacement version of the Jumo 204, initially known as the Jumo 5, 1933.
Jumo 206, diesel, higher power version of 205, 1936.
Jumo 207, diesel, supercharged version of 205, 1939.
Jumo 208, diesel, enlarged variant of 205, c.1940
Jumo 209, diesel, unbuilt development of 207/208
Jumo 210, initially known as L10, petrol inverted V12, c. 1932.
Jumo 211, petrol, inverted V12, enlarged variant of 210, 1936.
Jumo 212, petrol, projected inverted V24 with two Jumo 211 engines.
Jumo 213, petrol, inverted V12, revised, improved version of 211, 1940.
Jumo 218, diesel, unbuilt 12 cylinder version with two 208 engines.
Jumo 222, petrol, 24-cylinder, 6-bank radial, 1939.
Jumo 223, diesel, experimental 24 cylinder with four 207 engines arranged in a box shape.
Jumo 224, diesel, higher power version of 223, development continued in the Soviet Union.
Jumo 225, petrol, projected 36-cylinder, multi-bank radial developed from the 222.
Junkers 109-004, turbojet, 1940.
Junkers 109-012, turbojet, few completed by Soviets, 1946.
Junkers 109-022, turboprop, project completed by Soviets, 1950.