Junkers G 24

The Junkers G 24 was a German three-engine, all-metal low-wing monoplane passenger aircraft manufactured by Junkers from 1925. Junkers F 24 was the designation for single-engine versions of the same aircraft.


Junkers G 24
Class Aircraft
Type Bomber
Manufacturer Junkers
Origin Germany
Country Name Origin Year
Germany 1924
Country Name Operational Year Retirement Year
Afghanistan View
Australia View
Brazil View
Chile View
Finland View
Germany 1925 View
Greece View
Italy View
Poland View
Russia (USSR) View
Spain View
Sweden View
Switzerland View
Turkey (Ottoman Empire) View
Yugoslavia (Serbia) View
ManufacturerName Production From Production To Quantity
Junkers 115 View

The increased German air traffic in the 1920s led to a requirement for a larger passenger transport aircraft. The G 24 was an enlarged development of the F 13. It was originally designed by Ernst Zindel as a single-engine aircraft. Under the restrictions imposed on aircraft in Germany by the Treaty of Versailles, only low powered engines were allowed. So the Junkers company designed their large G24 airliner to be single-engined, but built it as a tri-motor. With three low powered engines the G24 could fly, but was not a viable airliner. The plan was to sell the tri-motors to airlines outside of Germany, who would then install a single, high-powered engine (e.g. 450 hp Napier Lion) on the nose, and simply remove the wing center-section plugs that carried the other two engines. However the Military Inter-Allied Commission of Control declared the G24 design to be a military type aircraft, and outlawed it.

Junkers then resubmitted what was essentially the same design, but under a new designation: Junkers G23. The Allied Commission ultimately allowed Junkers to build the G23, even in the single engined version, because it was clearly an airline type. The plane was always marketed under the G24 designation. (This paragraph based on 'Wagner' pages 230 - 234)

Junkers continued to build the G24/G23 as a tri-motor, because the ruse to circumvent the Allied restrictions also had the benefit that the plane could fly, and even climb, with one engine out. In 1925 most airliners were single-engined, since one big engine will usually be more efficient than several small ones. Twin-engine types could not maintain altitude with an engine out, unless they were so overpowered that the airlines could not afford to operate them. A tri-motor did not have to be so grossly overpowered, to be able to fly with an engine out.

On May 1, 1926 newly formed German airline Deutsche Luft Hansa started flying passengers on the route Berlin - Königsberg at night using G24 aircraft ('Wagner' page 232'Seifert' page 376). This was the first time any airline, anywhere in the world, flew passengers at night. Previously airlines had flown only mail and freight after dark. If an engine failed, the pilot bailed out by parachute, since a forced landing in the dark is too dangerous. The Junkers G24 could carry passengers, since there would not be any forced landings. The G24s of Luft Hansa also had blind flying instruments and radio navigation (with the radio operator sitting in the passenger cabin, as there was no room in the open two seat cockpit).

The aircraft was manufactured in three main batches, with different engine alternatives. Between 1925 and 1929, at least 72 aircraft were manufactured, 26 of which went to Luft Hansa. The G 24 managed to set a number of aviation records involving pay loads. Fritz Horn flew 2,020 km (1,560 mi) with a payload of 1,000 kg (2,200 lb) on 14 h 23 min, having an average speed of 140 km/h (90 mph), setting a new world record.

On 24 July 1926, two G 24s became famous after having flown the 20,000 km (12,400 mi) route between Berlin and Peking in just 10 stops. This flight ended on 8 September. It was initially meant that they would fly all the way to Shanghai, but they were prevented by military conflicts. On 26 September 1926, the two aircraft landed again in Berlin. Later during the year, a trans-Euro-Asiatic line was created.

Luft Hansa, which operated the largest G 24 fleet in the world, decided to modify their G 24s to a single engine standard. The first modifications were done in March 1928. The wing was shortened and the center engine was replaced with a BMW VIU engine. Junkers called this aircraft F 24ko. A total of 11 G 24s were modified to F 24 standard between 1928 and 1930. By July 1933, most of these BMW-equipped F 24s were again modified with the new Jumo 4 and designated as F 24kay. Most of these F 24s remained in service at the beginning of World War II in 1939. Most of them were used by Luft Hansa as freighter aircraft.

The Soviet-German aircraft cooperation in the 1920s let to a Soviet request for a new bomber aircraft.

Junkers then designed the Junkers Ju 25 as a twin-engine bomber. But the development of this aircraft was too expensive for Junkers, especially since there were some difficulties with his Russian partners. Junkers then advised his lead designers - Ernst Zindel and Hermann Pohlmann - to design a military derivate of the G 24. By November 1924, the new aircraft was ready, and given the designation G3S1 24 and it was a direct modification of the G 24ba. The aircraft was said to be an air ambulance. Junkers followed up this design with several reconnaissance designs e.g. the G1Sa 24 which was a modified G 24 with only a single engine. The next design, the G2sB 24 was also a bomber, directly derived from the G 24he. This aircraft had a new center wing section and a new nose section, to allow an open shooting area to the forward areas. Junkers decided to produce this design as the general military version of the G 24 and gave it the designation K 30 in 1926.

In 1926, the Finnish airlines Aero O/Y acquired a Junkers G 24, which went into service on the Stockholm route. The aircraft was equipped with floats, but not skis, and so could be used in summer only. It remained in service until 1935.

A Swedish G 24 also participated in the rescue of the unfortunate Italian Umberto Nobile expedition to the North pole. This was the first time an aircraft had flown over the Arctic Sea without stops.

Role Airliner-Transport
Manufacturer Junkers
First flight 19 September 1924
Introduction 1925
Primary users Deutsche Luft Hansa
Luftwaffe
Produced 1925-1929 (German production)
1924- (Sweden)
Number built Germany: ~72
Sweden: 20 + 23 K 30s


General characteristics

  • Crew: 2
  • Capacity: 14 passengers
  • Length: 15.8 m (51 ft 10 in)
  • Wingspan: 29.37 m (96 ft 4 in)
  • Height: 5.80 m (19 ft 0 in)
  • Wing area: 99 m2 (1,070 sq ft)
  • Empty weight: 4,330 kg (9,546 lb)
  • Gross weight: 7,200 kg (15,873 lb)
  • Powerplant: 3 × Junkers L5 6-cyl. in-line water-cooled piston engine, 230 kW (310 hp) each

Performance

  • Maximum speed: 210 km/h (130 mph; 113 kn)
  • Cruising speed: 170 km/h (106 mph; 92 kn)
  • Range: 660 km (410 mi; 356 nmi)
  • Service ceiling: 4,000 m (13,123 ft) with maximum payload
  • Rate of climb: 2.47 m/s (486 ft/min)
  • Time to altitude: 2,000 m (6,600 ft) in 13.5 minutes

End notes