DUTCH AND SWEDISH AIRCRAFT at Bromma Airport, Stockholm. Each of the Swedish routes connecting with foreign countries is flown in cooperation with the national air line of the country concerned. This photograph was taken in 1937 at the inauguration of non-stop air lines from Stockholm to Berlin and to Amsterdam.
SWEDISH aviation has successfully overcome a variety of difficulties caused by the climate and nature of the country. British, German and Dutch manufacturers have provided the machines which Swedish pilots operate, sometimes in Arctic conditions. Swedish prestige is maintained by the men who pilot the ambulance machines which serve remote parts of the country, by the pilots who have flown into the Arctic to the aid of explorers in difficulties, and by the pilots of the Swedish Air Lines. Swedish Air Lines are known in Sweden as A.B.A. or Aktiebolaget Aerotransport.
The first flights in Sweden were made as long ago as August 1909. In that year, at Stockholm, in the presence of 20,000 people, Folmer Hansen left the ground for three minutes, and then for two and a half minutes, in a Voisin biplane. Hansen had practised before in France. Legagneux, an experienced aviator, who had partnered him at Stockholm on August 6, 1909, flew more than a kilometre (five-eighths of a mile) with a passenger. The biplane made eight flights altogether, including two of more than three miles. The biplane, built by the brothers Gabriel and Charles Voisin at Billancourt, France, was similar to the machines they had built for Leon Delagrange and for Henri Farman. By guaranteeing that every machine they made could be flown, the brothers astonished the sceptics who had derided aviation. A buyer could obtain a machine by paying a small deposit and remitting the balance when he had made a flight.
Baron Carl Cederstrom, a member of one of the oldest families in Sweden, was the outstanding personality of the early days. He learned to fly in France, gaining his certificate — No. 74 — in a Bleriot monoplane. He bought the machine, took it to Scandinavia and devoted his energy to aviation. The Swedes called his Bleriot the Bilbot, the name being derived from the motor car company, Automobil Bolaget, of which he was a director.
One day when the engine faltered he landed on the side of a field farthest from his mechanics. Rather than wait for them, the impetuous Cederstrom left the ignition switched on, climbed out of the machine and swung the propeller. The engine fired and, as the machine gathered way, Cederstrom leant down so that the wing passed over him, then rose, seized the fuselage as it moved past, swung himself on board and took off. He repeated this acrobatic feat at many meetings.
Cederstrom was a clever engineer, in addition to being a good exhibition pilot, and he was determined to begin aircraft construction in his native land. He persuaded an engineering firm to establish an aviation branch, of which he took charge; later he founded a company. He lived to see the beginning of the determined effort made in Sweden to conquer the disadvantages which Nature had provided. In the summer of 1918 Baron Cederstrom, with Captain Krokstedt, chief of Cederstrom’s flying school, left Sweden to deliver a seaplane to Finland. The machine was seen over the Gulf of Bothnia and then vanished. Search was made and the wreckage was found; both aviators were dead.
Cederstrom was the most prominent of the band of pioneers who refused to be deterred by the long and severe winter, the large areas of sparsely inhabited country, and the lakes and mountains that complicate aviation in Sweden. Attempts were made to establish communication by air across the Baltic in the summer. At Stockholm the aim was to link the capital in the summer with Helsingfors (now Helsinki), Finland. At Malmo, in the south of Sweden and the third most populous city, it was hoped to operate the short route across the Ore Sound to Copenhagen, and the longer route across the Baltic to Warnemunde, Germany. A third objective was an air service to Gothenburg (Goteborg), the second largest city in Sweden.
Seaplanes were suitable in the summer not only for routes over the Baltic and connecting ports, but also for the innumerable lakes inland. On the other hand, there were remote areas, including some above the Arctic Circle, where aircraft were needed and landplanes were more suitable. For part of the year when sea and lakes were frozen, runners replaced floats or wheels, so that machines could land on ice or snow. A more difficult problem was to find an engine that would operate in cold weather. In winter the mean temperature in the extreme south is about freezing point (32° Fahr.) and in the north it falls sometimes to —13° Fahr.
During the war of 1914-18 Sweden was neutral and the pioneers of civil aviation hoped to secure machines to fly mail when peace was secured in Europe. At one time, in 1917, the Swedish Chamber of Commerce in London requested several authorities to examine the possibility of an air mail service between England and Sweden, and in Sweden the possibilities of air mail were discussed.
After the war several enterprising foreign aviators, including two Britons, Captain Saunders and Major C. H. R. Johnstone, arrived in Sweden with aircraft and did a considerable amount of flying. German aircraft constructors, prevented at that time from making military machines, devoted considerable attention to the neighbouring country of Sweden.
Memorable Pioneering Tour
In 1920 services were flown between Warnemunde and Malmo in the summer across the Baltic and also on the more exacting Baltic route between Stockholm and Helsingfors. In the summer of 1921 an experimental mail and passenger service was tried between Stockholm and the Estonian capital, Tallinn (formerly Reval), from July 11 to 29 inclusive. A Savoia 16 with a 300 horsepower Fiat engine and a Junkers seaplane with a 185 horse-power engine were placed on this route of 280 miles, which was flown in an average time of 2 hours 45 minutes. The Junkers made ten journeys and the Italian machine two.
A British visitor who included part of Sweden in a memorable tour of Europe was Alan (now Sir Alan) Cobham. Cobham was flying two business men in a D.H.9 four-seater round Europe. He stated at the time that he flew from Copenhagen to Stockholm, 350 miles, in 3 hours 55 minutes. Hills and mountains made the first half of the route picturesque but awkward, for Cobham did not see one good landing-place until he had entered the second stage. Then he noted that the lakes might afford landing-places for seaplanes in summer and for aircraft fitted with skis in winter.
On the next stage of the tour, from Stockholm to Norway, Cobham landed at Orebro, 110 miles, after a flight of 1 hour 45 minutes. Orebro is an inland port at the western end of Lake Hjalmar. Captain Saunders, who had then been flying in Sweden for about two years, was at Orebro giving an exhibition with an Avro. After Cobham had taken off he encountered a strong head wind, but the D.H.9 flew steadily over a mountainous region and across the border to Oslo, the Norwegian capital, covering the 180 miles in 2 hours 20 minutes.
WHEN THE INTERNATIONAL ROUTES WERE FIRST ESTABLISHED, a great deal of work had to be carried out at Malmo’s airport. Previously seaplanes had been extensively used, so that little consideration had been given to improvements in the land aerodromes There is a night mail service between Malmo and Stockholm, and the route is marked by a chain of beacons. This illustration shows the Varmland preparing to land at Bulltofta, the air port for Malmo.
Two years later Cobham was the outstanding pilot at the International Aeronautical Exhibition at Gothenburg. This exhibition was opened on July 20, 1923, by the King of Sweden, as part of the Gothenburg tercentenary celebrations. The exhibition was the first really international aeronautical exhibition held after the war, as the Germans were able to exhibit. The lifting of the ban on Germany put several nations on their mettle. British constructors sent aircraft, engines and accessories, and a number of prominent Britons, including Air Vice-Marshal Sir William Sefton Brancker, then the Director of Civil Aviation, travelled by air to Gothenburg. At that period the Swedish aviation companies had gone out of business. The success of the exhibition and the interest it rekindled in the Swedish nation enabled civil flying to be refounded on a successful basis.
The British machines were the centre of interest. They included the Avro Aldershot Cub, with a 1,000 horse-power Napier engine. This Avro was claimed to be the most powerful single-engined aircraft then in existence. The Napier Lion was the motive power of a number of British aircraft: a Blackburn Swift torpedo plane, designed to carry an 18-inch torpedo, a Vickers Viking Mark IV amphibian, a Handley Page 143 troop carrier, and a Fairey machine. The Fairey could also be supplied as a seaplane, driven by a Rolls-Royce Eagle IX motor.
Armstrong Siddeley showed their Siskin single-seater fighter, whose 320 horse-power Jaguar gave it a speed of 148 miles an hour. A Bristol Jupiter fighter with a 400 horse-power Jupiter, a Gloucestershire Grouse with a 230 horse-power B.R.2, and a Gloucestershire Grebe powered by a Jaguar, marked the importance British aircraft manufacturers attached to the show.
Swedish Service aviation has since been a valued customer of the British industry. Some of the machines are bought from Great Britain; others, of Swedish or foreign design, are powered by motors of British design made under licence in Sweden.
In the civil aviation section of the exhibition of 1923 De Havilland machines and British pilots were in the forefront. To mark the opening of the show, an arrival competition was held in which three British pilots competed.
Time-Keeping Test
This was a sporting event, and success depended not on fast speeds but on keeping to a declared speed. After Cobham had flown Sir William Sefton Brancker to Gothenburg he flew the first D.H.50 from England to Rotterdam, the starting-point of the contest. The D.H.50 had only just been completed. Cobham’s passengers included Admiral Mark Kerr, Mr. C. C. Walker (a director of the De Havilland company), and Mr. Norman (a mechanic).
Competitors had to declare their speed, fly to the control point at Bremen, Germany, and stay for one hour, proceed to Copenhagen, Denmark, for another stay of one hour, and then finish the course. The other two British contestants were Major H. Hemming, with a D.H.37, and Lieutenant Bird, whose machine was a Gloucestershire Grebe.
The pilots of the various nations began their calculations. Cobham was glad when his calculations were over, but, having spoken with the German crew of a Junkers machine, he found that the figures had to be expressed in kilometres and seconds, not in miles and minutes. He therefore went back to inform Mr. Walker that more calculations would have to be done.
Lieutenant Bird did not appear to be bothering about figures, much to the curiosity of one inquirer, who persisted in questioning him until Bird confessed, “I’m not worrying about fancy times. I’ve only got two hours’ petrol, and as long as my fan goes round I’ll get there”.
A sporting victory was won by a Swedish officer, Lieutenant Soederberg, the owner of a somewhat venerable Breguet. His revolution counter broke on the way, but did not rob him of success. Grase (Holland) was second, Zimmermann (Germany) third, Cobham fourth, Hemming fifth, Thiedemann (Germany) sixth, and Bird seventh.
A THREE-ENGINED JUNKERS AIR LINER of the Swedish Air Line at Bulltofta. The airport is two and a half miles east of Malmo and has large hangars, facilities for repair work, meteorological and radio stations. The size of the aerodrome is 1,094 yards by 875 yards.
Interest was centred in the competition for commercial aircraft. This competition was won by Cobham, who scored 999 points out of 1,000 with the D.H.50, the engine of which was a 240-horse-power Siddeley Puma. The course was between Gothenburg and Copenhagen; the event began on August 7, and continued for five days. Two hundred points were allocated for fuel economy, 350 for regularity of flying, 250 for speed and 200 for construction and special properties. Cobham lost the solitary point because he was ninety seconds late in starting one morning. A Junkers machine scored 950 points and was awarded second place.
The remarkable performance of the British machine was a tribute to the noted pilot and to the British aircraft industry. Such reliability had been shown that, although no member of the Swedish Royal Family had flown before, the two sons of the Crown Prince expressed a desire for a flight, and Cobham took them up with Sir Samuel Hoare and Admiral Mark Kerr. Later, when the British members of the party were about to return by air to England, Admiral Kerr wrote a letter to the two sons of the Crown Prince. Cobham flew over the country house in which they were living and the letter was delivered by air, being dropped neatly on the lawn.
A rigorous test made by the Swedish military authorities of a British engine in 1924 showed that engine designers had provided a motor which would enable Swedish aviators to fly in Arctic conditions. Previously, water-cooled engines had needed constant care; water and oil had to be drawn from an engine after a flight in the frozen north, and before starting a flight water and oil had to be heated. Air-cooled rotary engines had been tried, with results that did not satisfy requirements; with static air-cooled engines it had been necessary to drain the oil after each flight and to heat oil to a high temperature before beginning the attempt to start the cold motor in the morning.
The machine selected for the exacting test, a Bristol fighter fitted with skis, was powered by a Bristol Jupiter 400 horse-power radial air-cooled engine. The scene of the test was the aerodrome, 2,000 feet above sea-level, at Kiruna, well above the Arctic Circle, in latitude 67° 50' N. After a flight the Bristol was left in an unheated hangar all night and the oil was not drawn from the engine. Early in the morning the doors of the hangar were opened.
The “Flying Samaritans”
Later, when the temperature was 12° Fahr, the engine was started without a hitch, to the gratification of the Swedish officers, who then proceeded with an even more rigorous test. On the second test the hangar was left open throughout the night, although the temperature fell to —4° Fahr. The engine started at the second swing of the propeller, and the machine, piloted by a Swedish officer, Lieut. Garden, climbed easily to an altitude of nearly 10,000 feet in eight and a half minutes.
Then Lieut. Garden and a passenger took off for a flight of about 807 miles from Kiruna to Malmslatt, in the south of Sweden. There were two intermediate landings for food and fuel. The flying time was six and a half hours, and the average speed more than 120 miles an hour. The length of Sweden is such that had Lieut. Garden flown the same distance south from Malmo he would have reached Italy.
A similar test was made in 1926 with an Armstrong Whitworth Siskin, powered by an Armstrong Siddeley Jaguar, the pilot being Lieut. Lundborg. The reliability of engines such as these enabled Swedish aviators to fly in emergencies during terrible weather. Late one day in 1928 a message was received at the aviation centre of Ostersund, in central Sweden, that someone in a remote village 125 miles distant needed an urgent operation. Two officers set out in a machine, reached the village in eighty minutes and took off again with the patient after night had fallen.
They steered for Umea, on the river of that name near the Gulf of Bothnia, but fog added to the bitter cold and darkness. To help them, searchlights were directed on the river. The aviators flew above the town and saw the gleam of the searchlights just as their petrol was exhausted. They landed in a field not far from the town. The patient was taken to hospital, where an operation saved his life. The flight was marked by the award of the Swedish Medal for Merit to both officers.
THE REBUILT AERODROME at Bromma, which is the airport of Stockholm and is five miles north-west of the capital. The four asphalt runways for different wind directions are 875, 985, 985 and 1,313 yards in length. The remainder of the surface is grass covered. Night-flying radio and meteorological facilities are available.
The “flying Samaritans”, as the Swedish people call those who fly the ambulance machines, are stationed at various centres ready to fly to the aid of individuals in isolated regions. Some calls are to carry patients to hospital. Accidents in which injured persons need aid, and epidemics which occur in remote districts, are the causes of other calls. Even in Stockholm there is work for the air ambulance, which flies to the remote islands of the archipelago. The machine based on Boden, at the northern end of the Gulf of Bothnia, serves lonely areas, and the needs of the nomadic Lapps. Froson, in Jamtland, is the base of another crew of “flying Samaritans”.
In the field of transport operation the observer is impressed not only by the organization that has produced a service linking Stockholm and other cities with the capitals of Europe, but also by the versatile enterprise of Swedish Air Lines. The company carries air mail, engages in night flying, and enables people in all parts of Sweden to make pleasure flights. In addition, the personnel have made some splendid rescue flights in the far north. Moreover, the freedom from accident is remarkable.
The interest aroused by the exhibition of 1923 was not allowed to relax. A company was formed early in 1924 to begin flying as soon as the approach of summer made operations possible. The company decided upon the Junkers F 13 and bought six machines. To provide swift communication with Finland, the route from Stockholm to Helsingfors was worked from June 2 until August 23. The route from Malmo to Hamburg, flown from July to October 5, enabled busy southern Sweden to make contact with the chain of routes extending from the great German sea and airport.
From these modest but efficiently operated beginnings the air lines lengthened steadily through the years, not only in mileage but also in the length of the season. Progressively the length of the winter suspension of air services was shortened. In the beginning of 1929, when one of the coldest spells of the century gripped Europe as far west as London, the Baltic ice blocked the sea routes in the south. Aircraft began an emergency service, which operated from February 12 to March 16, a period when ships were unable to move.
The advantages of multi-engined aircraft were developed to the full. The company is said to have been the first to use three-engined aircraft for civil flying on an air route. It bought four Junkers. With these machines in service the Malmo-Hamburg line was extended to Amsterdam, where connexion was made with the routes to London and to Paris. Thus for the first time passengers from Sweden were able to reach these two capitals in one day. The service to Helsingfors from Stockholm was improved, and the short route from Malmo to Copenhagen gave promise of attaining the importance it has since achieved.
In the development of night mail Captain Carl Florman, of Swedish Air Lines, devoted himself to establishing contact with other parts of Europe. In 1928 he organized eight experimental flights between Stockholm and Croydon Airport. The year 1928 was an active year in Swedish aviation. The first night mail aeroplane was a Junkers F 13. This was a single-engined monoplane, the cabin of which was fitted as a mail compartment in which a postal official sorted letters, to test whether sorting in flight was worth the extra weight of the official in accelerating the post.
10,000 People Flown by One Pilot
Another member of the company, Captain A. Ahrenberg, one of the first traffic pilots, proved his outstanding ability in all-round flying, from piloting an air liner to flying over the Greenland ice-cap in quest of an explorer. He began as a military pilot. Test piloting and instructing cadets followed, and he then became pilot of an Aerotransport machine.
In 1927 the company decided to bring flying to as many people in Sweden as possible. Captain Ahrenberg went on tour from Ystad, in the extreme south of the country, to Kiruna, beyond the Arctic Circle, visiting 140 places and taking 8,428 passengers for trips.
He did more passenger-carrying in 1928 on another “round Sweden” tour, when he gave exhibitions of flying at 124 centres and carried more than 10,000 passengers.
One of his best known flights was in April 1931, when he was commissioned to go to the relief of Augustin Courtauld, the British explorer. H. G. Watkins, however, had reached his fellow explorer. Captain Ahrenberg located them and saw that they were safe.
Traffic pilot N. V. Nilsson flew the company’s machine, the Uppland, to the aid of the crew of the Italia, General Nobile’s airship. His flight across the Arctic Ocean to Svalbard (Spitsbergen) is said to be the first to have been made without an intermediate landing. Before the Uppland arrived Nobile had been rescued by Lieut. Lundborg, of the Swedish Army, flying a Fokker C.V. powered by a Bristol Jupiter.
THE MAJORITY OF AIR ROUTES from Sweden to other European countries are via Copenhagen. Malmo and Stockholm have the two most important aerodromes in Sweden. German and Dutch aircraft are used by Swedish Air Lines.
Lundborg had a mishap during a second trip to the airship to take off men and was rescued by Lieut. Schyberg, who flew a Moth seaplane. Traffic pilot E. Roll, a veteran of the company, made a flight in 1930 to Tromso, far north in Norway to fetch some photographs of the relics of Andree, the balloonist whose remains were found in the summer of that year (see the chapter “Flight of the Eagle”).
More powerful aircraft were put into service on the air lines in 1932. The Varmland, a Fokker seating fourteen passengers, was powered by three Pratt and Whitney Wasp engines developing a total of 1,650 horse-power. The Sodermanland, a Junkers Ju.52, had three Pratt and Whitney Hornet engines, which developed 1,725 horsepower. At this time the line announced that there had been no injury to the hundred thousand passengers which it had carried in eight years.
Considering the nature of the country, this immunity from accident showed remarkable efficiency of operation.
Other types which were added to the fleet were the Northrop Deltas, single-engined monoplanes which were useful on the new service from Stockholm to Turku (Abo), Finland, and Tallinn, Estonia, to connect with the service to Leningrad, U.S.S.R. By 1935 the Lappland, a four-engined Fokker F.22, with two pilots, radio operator and a steward to attend the twenty-two passengers, was on the route to Amsterdam.
By the early part of 1938 the types of aircraft used by the company were Junkers Ju.52, W.33, W.34 and F.13, Fokker F.12 and F.8, and three Douglas DC-3s. The newest machine was a Junkers Ju.86, equipped with three Pratt and Whitney Hornets of 715 horse-power each, giving a maximum speed of 217 miles an hour. Fitted for night mail, the machine is intended for the Stockholm-Malmo-Hanover route.
Each of the routes connecting with foreign countries is flown in cooperation with the national air line of the country concerned. From Stockholm the trans-Baltic route is to Turku, 168 miles, and to Helsinki, a total distance of 262 miles. Important island routes from the capital are to Mariehamn (Aland Isles) and to Visby (Gottiand). The direct route to Berlin is south-westwards, skirting the coast and then crossing the Baltic.
Night mail is flown between the capital and Malmo, but the passenger route is via Copenhagen. Norrkoping, situated south-west of Stockholm, is on the route between the two capitals. Malmo, sixteen miles from Copenhagen, is so near that passengers bound to or from Stockholm and Gothenburg use Copenhagen as the junction. From Gothenburg there is an air route to Oslo, Norway.
The Scandinavian Air Express operates from Stockholm throughout the year, Dutch, Finnish, Danish and French lines cooperating with the Swedish company. The route from London is via Amsterdam, Copenhagen and Norrkoping; in summer the express goes on to Finland. The 7.30 a.m. aeroplane from Croydon is scheduled to arrive at Stockholm at 2.55 p.m. The noon machine from Paris via Copenhagen is due at 6.45 p.m. A service from London by British Airways via Hamburg takes seven hours for the distance of about 1,000 miles.
A FOKKER F XII AIRCRAFT of Swedish Air Lines, the Varmland, which seats fourteen passengers. It is powered by three Pratt and Whitney Wasp engines which develop a total of 1,650 horse-power. This aeroplane was put into service in 1932 with other new aircraft. At this time it was claimed that 100,000 passengers had been carried without injury on the Swedish Air Lines in eight years
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