AB Aerotransport and the Junkers G 24

By: Rob Mulder
For: www.europeanairlines.no

One of the most important aircraft factories of the period before 1945 was the Junkers Flugzeugwerk AG – Jfa. It produced the first useable all-metal aircraft. The first all-metal fighters were already constructed during the Great War (1914-1918) and after the war Junkers continued to develop military and civil aircraft of all-metal construction. Famous is the three-engined series of civil aircraft: Junkers Ju 252, Junkers Ju 52/3m, Junkers G 31 and Junkers G 24. Latter aircraft has been widely used by the Swedish airline company AB Aerotransport (AB standing for Aktiebolag – Limited company).

AB Aerotransport

After the failure of the Svensk Lufttrafik AB – SLA to establish itself as the national airline company of Sweden, Carl Florman saw the potential to start up a new initiative. During his stay in the United Kingdom for the Swedish Government he met Geoffrey De Havilland and it was understandable that he took contact with him once he developed his idea of a national Swedish airline company. Florman wanted to purchase De Havilland DH.50s and start up airmail services. Delay in the delivery of the aircraft led to problems for Florman and he came into contact with Jfa. This company was willing to invest in AB Aerotransport and so it did. It will take to many pages to explain the structure of the ownership of the AB Aerotransport, but one thing can be confirmed and that is the fact that for some years Jfa invested and owned much of AB Aerotransport. In the first year of operation (1924) the AB Aerotransport used the Junkers F 13s, but Jfa had developed a new reliable three engine all-metal monoplane, which it wanted to enter service in 1925. John Stroud wrote in his book European Transport Aircraft since 1910 that the aircraft could be “regarded as the precursor of all the multi-engine all-metal low-wing monoplane transport aircraft which represent the standard form of today”. And this is a true statement. What John Stroud did not know at the time was the fact that the type designation G 23 did not exist at all. Junkers specialist Lennart Andersson explained in his book about AB Flygindustri i Limhamn 1925-1935 that “the G 24 for a short period in 1925-26 was called G 23. Although many publications state so, the G 23 and G 24 were not different aircraft. The designation G 23 was normally used only outside the company (i.e. Jfa – Rob Mulder) (in contacts with customers, authorities etc.). The J 23 was a completely different type, the single-engined T 23 private aircraft. Afi (i.e. AB Flygindustri – the Junkers-affiliated aircraft factory in Sweden – Rob Mulder) stopped using the G 23 designation already in 1926, but both ABA and the Swedish authorities, which did not know the background, continued to use this designation for the aircraft purchased in 1925. As these machines had different engines, etc, it was later assumed that the G 23 designation indicated a different version or a different type. This was not the case.

The Junkers G 24

In September 1924 the Junkers G 24 made its first flight. It was a low-wing cantilever monoplane and the prototype was powered by one single 230 hp Junkers L 2 and two 120 hp Daimler D IIa. The enclosed cabin offered seats to nine passengers and there was an open cockpit for two pilots. In the beginning the assembly was in Sweden at Jfa sister company AB Flygindustri and the first aircraft delivered to AB Aerotransport came from the Malmö-based factory.

Already in October 1924 AB Aerotransport ordered at Jfa four Junkers G 24s pending Swedish State subsidy. The order was confirmed by Jfa with the order number 480 and indicated that the delivery of the first two aircraft would take place in March 1925. This was followed by the delivery of the other two aircraft in respectively April and May 1925. In March the Swedish Riksdagen (Parliament) approved the concession and AB Aerotransport was allowed to operate the air services Stockholm – Helsinki, København – Göteborg – Oslo (Copenhagen – Gothenburg – Oslo) and Malmö – Hamburg – Amsterdam. AB Aerotransport could also purchase the Junkers G 24, but this would partially be done through a new AB Aerotransport-owned company called AB Flygmateriel (Aero Equipment Ltd). This company would pay for the Junkers G 24 and lease them on to AB Aerotransport. Once the financial situation in AB Aerotransport was sound the airline company could buy the aircraft.

On May 2, 1925 Robert Holmèn made at Malmö/Bulltofta the first test flight with AB Aerotransports first Junkers G 24, the WNr 833 (Werknummer – constructor’s number). Seven days later it was registered as S-AAAD Götaland on the name of AB Flygmateriel, who transferred the aircraft to AB Aerotransport for use. Three days later (May 12) the next two aircraft were delivered: S-AAAE Svealand (WNr 836) and S-AAAF Skåne (WNr 837). One month later on June 10 the last aircraft was delivered: the S-AAAG Norrland, WNr 838. The aircraft all had three 220 hp Junkers L 2 engines.

The world’s first air service operated by a three-engined aircraft

On May 13 the newly delivered Junkers G 24, S-AAAD flew to Amsterdam/Schiphol in order to be able to open the new air service Malmö – Hamburg – Amsterdam from there. Two days later, on Friday, May 15, 1925 AB Aerotransport inaugurated with the Junkers G 24, S-AAAE the world’s first air service operated by a three-engined aircraft from Malmö to Hamburg and Amsterdam. This was a great improvement compared with the single-engined Fokker F.III and the Dornier Merkur used so far by the competitors. KLM did not receive its first three engined aircraft until October 1925: the Koolhoven FK.33. This aircraft did not satisfy the needs. It was not until the introduction of the Fokker F.VIIb-3m that KLM could put up a competitive aircraft.

AB Aerotransport used all its four Junkers G 24s on the route to Amsterdam. This service was officially closed on September 30. But AB Aerotransport and Junkers Luftverkehr AG – Jlag continued to fly without any subsidy. AB Aerotransport only received an imbursement from the Generalpoststyrelse (the Swedish Mail Office), but when this ended (December) AB Aerotransport and Jlag flew the service until it was finally closed down on December 22. From October 1 until December 22, the route was operated with a minor adjustment. The service started in Malmö, but after the landing in Hamburg it continued to Amsterdam via the city of Essen/Mülheim in the Ruhr area. The service was now operated in co-operation with the Junkers-affiliated airline companies Luftverkehrsgesellschaft Ruhrgebiet AG – LURAG and NV Nederlandsche Wereldverkeer Maatschappij – NWM.

In September 1925, AB Aerotransport chartered a fifth Junkers G 24, the S-AAAX (WNr. 904). Jlag and Sächsische Luftverkehrs AG owned it and chartered it to AB Aerotransport for a three months period. In December it returned to Germany and went in January 1926 with the Swedish registration to Deutsche Luft Hansa AG. In June it was re-registered D899.

The Swedish Junkers G 24s were in 1925 only used on the air service to Amsterdam. The Stockholm – Helsinki service was still operated by Junkers F 13 with floats.

Co-operation on the Malmö – Amsterdam service

In the period April 19 to October 9, 1926 the Junkers G 24s have been used on the air service to Amsterdam and AB Aerotransport was responsible for 100 % of the traffic up to July 14, after which date the Deutsche Luft Hansa AG took over 50 % of the traffic. The German company used the Junkers G 24 as well. In the approximately the same period Dutch KLM operated a competing service from Amsterdam to Malmö. An agreement between KLM and AB Aerotransport made it possible for both companies to work together on the air service in 1927, 1928 and 1929. During three months in 1927 and 1928 traffic was doubled and both companies operated a daily flight (only on Monday to Friday).

KLM operated the service with the single-engine Fokker F.VII for eight passengers and from 1928 also with the single-engine Fokker F.VIII (12 passengers).  The co-operation went fine. The pool agreement was such that the incomes and expenses were divided between the two companies. But one kilometre flown by the Fokker F.VIII was compensated with 55/45 part of one kilometre flown by the Junkers G 24. This system was changed in 1929 when KLM operated the service with smaller aircraft than AB Aerotransport did.  The Swedish authorities paid the first year 1,75 Swedish Crowns per flown kilometre, increased to 2,50 Swedish Crowns in 1927 and reduced to 2,45 Swedish Crowns in 1929. Regularity on the air service is impressive with figures high up in the nineties, but the economical results were far from satisfactory.

Results on the route for the period 1925-1929 are:

Source: Sveriges Offentliga Utredningar (SOU) 1929 nr 21. For 1929 are only approximate figures known.

Malmö – København – Göteborg – Oslo

In 1926 the Junkers G 24s were again used between Malmö and Amsterdam, but in addition an air service to Oslo was scheduled to open. Lack of a Norwegian subsidy and airline company made it impossible for AB Aerotransport to open the air service København – Göteborg – Oslo. In order to promote the foundation of a Norwegian partner AB Aerotransport chartered in the autumn of 1926 a Junkers F 13, the S-AAAB, to A/S Norsk Aerotransport for joy-ride flights over Oslo. On the left can be seen a timetable from June 1925 including a red line between Göteborg and Oslo. It did not get that far until 1927.

The route between København and Göteborg was changed into a service from Malmö via København to Göteborg and inaugurated on July 1, 1926 by the Junkers G 24, S-AAAG. For this route the aircraft had been renamed Västkusten (West coast). Beside the S-AAAG, AB Aerotransport also used the G 24s S-AAAF and S-AAAE. The results were disappointing and therefore the smaller Junkers F 13, S-AZAA was used on a regular base as well. At the end of August the route was closed down and by then 483 passengers were transported in addition to 2,605 kg of luggage, 117 kg of airmail and 133 kg of freight.

In 1927 the air route was re-opened on June 1, but now mainly Junkers F 13s operated the service with occasionally a Junkers G 24 (only twice). The Junkers F 13, S-AWAA made on July 16 the last flight over the route. On Monday July 16, 1927 the Deutsche Luft Hansa AG opened a route from Stettin to Oslo via Göteborg and København and took over the traffic from AB Aerotransport. The Swedish airline company transported until the closure of the route 250 passengers, 2,041 kg luggage, 29 kg mail and 522 kg freight.

Stockholm – Helsinki and the Junkers G 24W

The letter W stands for the German word Wasser – water, i.e. a Junkers G 24 with floats. AB Aerotransport was interested to replace the Junkers F 13W with the G 24W on the Stockholm – Helsinki route. The original plan was to purchase two Junkers G 24W , but in the end one of the land-based aircraft was returned to Jfa and a new aircraft taken over. But it would take until 1927 til an aircraft of this type entered service with AB Aerotransport. In May the Junkers G 24ce was registered as S-AABG Uppland (WNr 904) to AB Flygmateriel and chartered to AB Aerotransport. It was used during the summer season on the air service between Stockholm and Helsinki.  In 1926 the pool partner on this route, Finnish Aero O/y, had already purchased one Junkers G 24W (WNr 919) and registered it in Finland as K-SALC Suomi.  Both companies operated the service six times per week and it was one of the most important services in the Baltic area. In 2004 it has been 80 years in operation. In June 1928 the S-AABG Uppland participated on behalf of the Swedish Government on a rescue mission to the Nobile-expedition around Spitzbergen. The flight between Tromsø (Norway) to Spitzbergen was covered in 6 hours and 10 minutes. Upon arrival a number of search flights were made.

AB Aerotransport used in the season 1924, 1925, 1926 and part of 1927 only Junkers F 13Ws on the air service, but after the return of the Junkers G 24ce from Spitzbergen the capacity on the line increased from four to nine passengers.

The line was subsidized from Swedish side by 1,50 Swedish Crowns per flown kilometre and later increased to 1,85 Swedish Crowns (1927) and 2,50 Swedish Crowns (1928), but reduced to 2,30 Swedish Crowns (1929). The occupancy figure was in 1928 too low (40 %) and thus the used aircraft (Junkers G 24s) were regarded as too big. Nevertheless the type was still used in the following years. The Swedish aircraft was during the winter season converted into a land-based aircraft and operated on the Malmö – Hamburg – Amsterdam service.

Source: Sveriges Offentliga Utredningar (SOU) 1929 nr 21. For 1929 are only approximate figures known.

Malmö – (København –) Berlin

The last regular air service where AB Aerotransport used the Junkers G 24 was between Malmö and Berlin. In 1925 the Junkers-affiliated airline company Dansk Lufttransport AS operated the service in pool with Jlag and AB Aerotransport and in the autumn Det Danske Luftfartsselskab AS joined. In 1926 and after the formation of the Deutsche Luft Hansa AG the Swedish airline company started a co-operation. In 1926 the service was operated between April 19 and July 14 with a frequency of six times per week. Until July 14 all flights were made by the DLH. On July 15 AB Aerotransport joined in and flew 50 % of all traffic. As compensation DLH took over 50 % of the traffic between Malmö, Hamburg and Amsterdam.

AB Aerotransport operated also a direct connection between Malmö and Berlin between July 15 and October 2, 1926. Both companies operated the services with the Junkers G 24. After October 2 DLH operated the service alone. The same frequency was upheld in the period 1927-1928, but in 1929 the co-operation was discontinued.

Source: Sveriges Offentliga Utredningar (SOU)

1929, nr 21.

What happened to the aircraft

During the years after 1929, AB Aerotransport operated the same services with great regularity and did not start any new services, except an airmail night service between Malmö, Hannover and Amsterdam in co-operation with the Dutch and German airline companies.

In 1929 Jfa published a table about the flying hours and kilometres flown of the aircraft of AB Aerotransport. We publish this table here including the figures for the Junkers F 13s. All figures are per December 31, 1928:

Despite several improvements during their life, the aircraft aged and in the beginning of the thirties replacements were sought and found in the Junkers Ju 52/3m. At the end of the twenties AB Aerotransport was offered the Junkers G 31, but refused the offer as it regarded the aircraft as too big for its services (the G 31 took fifteen passengers). In 1929 the aircraft were re-registered as follows:

In December 1925 the first aircraft to leave AB Aerotransport was S-AAAX. But the first of the purchased aircraft to leave AB Aerotransport service was the Junkers G 24, S-AAAD Götaland. This aircraft was sold to Junkers Flugzeugwerk AG in May 1927 to cover partially the payment of the Junkers G 24ce, S-AABG. Jfa sold it to the Spanish airline company Union Aeréa Española, where it flew as M-CABB. In service with AB Aerotransport the aircraft had flown 91,100 kilometres and made 658 flying hours.

The first aircraft to be lost in service was the Junkers G 24, SE-AAF. On August 29, 1929 the pilot was confronted with engine troubles and crashed subsequently near the border of the Netherlands and Germany.  During the landing the aircraft rolled into a wood and was damaged beyond repair. Passengers and crew remained unhurt. In AB Aerotransport service it flew 236,200 km in 1,717 flying hours.

Next was the Junkers G 24, SE-AAG. This aircraft was lost in a fire at Malmö/Bulltofta on June 11, 1931. The aircraft was in the hangar for an overhaul and one of the workers dropped an electric lamp that lightened oil and petrol on the floor. The aircraft was set on fire before the rest of the hangar. In AB Aerotransport service it flew 263,700 km in 1,792 flying hours.

The Junkers G 24, SE-AAE was the last aircraft to be lost in a crash or accident. On August 30, 1932 the experienced pilot Karl Bernhard Liljeberg crashed with this aircraft on the night airmail service Amsterdam – Hannover – Malmö. On board was also the radio operator Uttergård. The pilot wanted to make an extra-ordinary landing and was looking for an emergency airfield. He collided during his search into a house. The aircraft was destroyed beyond repair and both crewmembers lost their life. In AB Aerotransport service it flew 367,100 km in 2,476 flying hours.

That brings us to the last aircraft in service, the Junkers G 24, SE-ABG Uppland. This aircraft was used a payment for a new Junkers Ju 52/3m that was delivered in 1932. The aircraft went to Afi. This company sold it to Germany as D-1005 to the Reichsbund der deutschen Verbrauchsgenossenschaft (1933). In AB Aerotransport service it flew 200,800 km in 1,182 flying hours.

In September 1932 the last flights with the Junkers G 24 were made and one of the most popular aircraft in Swedish service had stopped flying. The modern Junkers Ju 52/3m were to take over their work. But that is a different story.

I would like to thank Lennart Andersson for taking time to check the fleet data and supplying the picture of the Junkers G 24, SE-AAE.  The timetables come from the website of Björn Larsson and David Zekria: http://www.timetableimages.com/index.htm. Please visit this website for great enjoyment.