The Junkers A50 Junior is a German all-metal sports plane first produced by Junkers in 1929. A modernized version, produced since 2022 by Junkers Aircraft Works, features updated materials, safety systems, and avionics.
Designed by Hermann Pohlmann during the late 1920s, it incorporated the all-metal construction and various other principles practiced on Junkers' larger aircraft of the era. The A50 had a streamlined fuselage composed of corrugated duralumin, a low-mounted cantilever wing, and proportionally large flight control surfaces. It could be outfitted with conventional landing gear, skis or floats to suit a variety of operational conditions; the aircraft was reportedly suitable for use in the tropics or near-Arctic conditions as well as from austere airstrips. It was typically powered by a single Armstrong Siddeley Genet II engine, although other powerplants could also be fitted.
In 1930, a floatplane variant of the Junkers A50 Junior set eight Fédération Aéronautique Internationale (FAI) world records for altitude, distance, and average speed. In 1931, German aviator Marga von Etzdorf became the first woman to fly solo from Berlin to Tokyo, completing the journey in a Junkers A50 Junior.
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Development
The Junkers A50 was the first sports plane designed by Hermann Pohlmann in Junkers works. It had the same modern all-metal construction, covered with corrugated duralumin sheet, as larger Junkers passenger planes. On 13 February 1929, the A50 conducted its maiden flight. Four additional prototypes followed, several equipped with different engines for testing.
Junkers expected to produce 5,000 aircraft, but halted manufacturing only 69 A50s, only 50 of which were ever sold. Sales remained modest; the aircraft was priced between £840 and £885 in 1930. Apart from Germany, they were used in several other countries and some were used by airlines. The purchase price in 1930 in the United Kingdom was between £840 and £885. Starting from the A50ce variant, the wings could be folded for easier transport.
Three Junkers A50 participated in the Challenge International touring plane competition (July 1929), placing 11th (A50be, piloted by Waldemar Roeder) and 17th. At the Challenge 1930, three A50 competed again, achieving 15th, 27th, and 29th place rankings. In June 1930, a series of eight FAI world records for altitude, range and average speed were set on a floatplane variant of A50, powered by the Armstrong Siddeley Genet II 59 kW (79 hp) engine. During 1931, Marga von Etzdorf flew an A50 solo from Berlin to Tokyo, the first woman to do so.
Design
The Junkers A50 was a sports plane that featured a conventional configuration, all-metal construction, a low-mounted cantilever wing, and a stressed corrugated duralumin exterior. It was promoted for its adaptability, being as equally suitable for use during summer as it was during the winter, on land or at sea, and in the tropics or near-arctic conditions. The A50 conformed with several conventions for Junkers-built aircraft, such as the placement of the pilot in the rear seat while the passenger sat in the forward position. Both positions were provided with dual flight controls and two complete sets of instruments.
The fuselage was a precisely streamlined tube of corrugated duralumin; in spite of its extensive use of metal, it was carefully designed so that it achieved the typical weight limits of mixed-construction aircraft (e.g. those that used fabric and wood). It was supported by a number of formers and bulkheads that had provisions for easy access that permitted both inspection and repairs to be performed. The nose of the fuselage accommodated the aircraft's single engine while the rear of the fuselage tapered into a vertical wedge that extended upwards to form the fin.
Having been designed to serve as a touring aircraft, several aspects of the aircraft, such as the comfort and convenience of the occupants, were addressed in detail. The two seats present in the cockpit, used by the pilot and a single passenger, were relatively well-upholstered, broad, and fitted with an adjustable back and arm rests. Two separate baggage compartments were provided for the carriage of even particularly heavy suitcases; one, positioned between the two seats, was within easy reach of either occupant throughout the flight. The second baggage compartment, behind the pilot's seat, was large enough for a single streamer trunk. Piping in the vicinity of the cockpit was concealed by the aircraft's double bottomed fuselage.
The wing was divided into a central section, which was integral with the fuselage, and two outer sections that were joined to the centre using no more than four screws each; this aided ground transportation as well as repair work, the outer sections being readily replicable by a substitute. Akin to the fuselage, the wing was covered in stressed corrugated duralumin. Structurally, it was relatively simplistic, dispensing with many typical supporting devices, such as ribs; this simplicity benefitted both production and service staff alike. Several mundane defects, such as bulges, were felt to be reasonably addressable by the owner themselves. For more space-efficient storage of the aircraft, the wings could be folded rearwards on some models.
New production
In 2022, Junkers Aircraft Works began production of a modernized version of the A50 known as the A50 Junior. This new A50 features modern avionics, a 100 hp (75 kW) Rotax 912iS engine driving a composite MT-Propeller, and a ballistic parachute. As of May 2023, 27 new A50s have sold in Europe, and plans have been made for WACO Aircraft Corporation to produce aircraft for American customers.
During the 2024 Sun 'n Fun Aerospace Expo, Junkers unveiled the A50 Heritage. The A50 Heritage is marketed as a more authentic version closer to the original A50. It is powered by a Verner Scarlett 7U radial engine and features a two-piece glass windscreen and analog instruments.
Variants
Original production
A50 - Armstrong Siddeley Genet 59 kW (79 hp) radial engine
A50ba - Walter Vega 63 kW (84 hp) radial engine (one built)
A50be - Armstrong Siddeley Genet 59 kW (79 hp) engine
A50ce - Armstrong Siddeley Genet II 63 kW (84 hp) engine or for export Genet Major I 74 kW, folding wings
A50ci - Siemens-Halske Sh 13, 65 kW (87 hp) radial engine, folding wings. Originally designed to be mass-produced as a "Volksflugzeug".
A50fe - Armstrong Siddeley Genet II, 63 kW (84 hp) engine, modified airframe, folding wings
KXJ1 - A single Junkers A-50 supplied to the Imperial Japanese Navy Air Service for evaluation.
The -ce and -ci variants were produced in the largest numbers with about 25 of each on the German civil register. Due to their construction, the A50 were durable aircraft and they lasted long in service. The last plane was used in the 1960s in Finland. There is one A50 preserved in Deutsches Museum in Munich and another in Helsinki airport. One A50 (VH-UCC, c/n 3517) is in airworthy condition in Australia.
New production
A50 Junior - Modernized version of the original A50 powered by a 100 hp (75 kW) Rotax 912iS engine.
A50 Heritage - Version powered by a Verner Scarlett 7U with a two-piece windscreen and analog instruments.
Operators
Argentina
Argentine Air Force
Australia
Royal Australian Air Force
Bolivia
Bolivian Air Force - 3 A50s transferred from Lloyd Aéreo Boliviano during Chaco War
Lloyd Aéreo Boliviano - 3 A50s used for training and light transport
Brazil
Brazilian Air Force
Finland
Finnish Air Force
Germany
Reichswehr
Nazi Germany
Luftwaffe
Hungary
Hungarian Air Force
Japan
Imperial Japanese Navy
Paraguay
Paraguayan Air Force
Portugal
Portuguese Air Force
South Africa
South African Air Force
South African Airways operated three aircraft
Sweden
Surviving aircraft
As of 2020, OH-ABB, a surviving Junkers A50 Junior flown by Finnish aviator Väinö Bremer on record-setting long-distance flights in the 1930s, is displayed at the Finnish Aviation Museum.
Specifications (A50ba)
Data from Junkers aircraft and engines, 1913-1945, Junkers: an aircraft albumGeneral characteristics
Length: 7.12 m (23 ft 4 in)
Wingspan: 10 m (32 ft 10 in)
Height: 2.39 m (7 ft 10 in)
Wing area: 13.7 m2 (147 sq ft)
Empty weight: 340 kg (750 lb)
Gross weight: 590 kg (1,301 lb)
Fuel capacity: 95 L (25 US gal; 21 imp gal)
Powerplant: 1 × Armstrong Siddeley Genet II five-cylinder air-cooled radial piston engine, 65 kW (87 hp)
Propellers: 2-bladed fixed-pitch propeller
Performance
Maximum speed: 164 km/h (102 mph, 89 kn)
Cruise speed: 140 km/h (87 mph, 76 kn) on 60% power
Landing speed: 75 km/h (47 mph; 40 kn)
Range: 600 km (370 mi, 320 nmi)
Endurance: Five hours
Service ceiling: 4,200 m (13,800 ft)
Time to altitude: 3,000 m (9,800 ft) in 21 minutes
Take-off run (over 8 m (26 ft)-high gate): 250 m (820 ft)