Towards the North Pole
Marina di Pisa–Tromso–Kings Bay–Arctic Ocean, 25 February 1925–21 May 1925
At about 17:10 on 21 May 1925 two Dornier Wal flying boats took off from the ice of Kings Bay, on the island of Spitsbergen, in the Svalbard archipelago. They flew in a loose formation and shaped a course for the North Pole. The crews consisted of Amundsen, Riiser-Larsen, Dietrichson and Omdal from Norway, Ellsworth from the United States and Feucht from Germany. In the days of sailing ships a ship was said to be sailing ‘towards’ rather than ‘to’ its destination and this seems an appropriate was to describe this flight. They were aware that the machines did not have the range to fly to the Pole and back non-stop. Their sextants were useless if the horizon was hazy or invisible. Without the observations the sextants navigation would be approximate rather than precise. They had no radios and would be on their own the moment they crossed the southern boundary of the sea ice which lay just to the North of Svalbard.
Amundsen and Ellsworth had chosen Ny Alesund, a settlement on the southern shore of Kings Bay as their base. There were several reasons for this decision. It was close to the Pole, 665nm away, and although it was isolated by the Arctic pack ice during the winter, it was accessible early in spring because of the warm Gulf Stream current. The expedition was planned to take place in the months that the sun was above the horizon 24 hours per day. In 1916 Peter S Brandal had started a coal mine at Ny Alesund and mining was in full swing when the Amundsen-Ellsworth expedition arrived in 1925. The settlement consisted of a wharf, machine shops, barracks, bathhouse, hospital, houses and a narrow gauge railway operated by horses. The machine shops and man-power were particularly valuable and might be needed for unloading and assembling the aeroplanes.
They had chosen Dornier Wal flying boats for the expedition. Their requirement was for a machine that could take off and land on water, ice or packed snow and be durable enough to survive in the Arctic environment. Amundsen had visited Marina di Pisa in Italy during 1924 and inspected the all-metal Dornier Wal flying boats that were manufactured under licence from Dornier in Germany. Germany was prohibited from manufacturing large aeroplanes by the provisions of the Treaty of Versailles which had terminated the Great War of 1914–1918. Italy allowed Germany to circumvent this provision even though it had fought against Germany in the war.
Amundsen was favourably impressed as the all metal structure seemed ideal and the bottom of the hull was almost flat and the machine used sponsons, (which looked like a small wings attached to each side of the hull beneath the wing) rather than tip floats, to keep the aeroplane from capsizing at low speed, or stationary, on the water. The large monoplane wing was placed on struts well above the fuselage and the two engines were mounted on the centre section of the wing, in tandem, where the propellers were as far away as possible from the spray which was part of every take-off and landing on water. The placing of the engines also had the advantage that if one failed the remaining engine was on the centre line and did not cause yaw and extra drag. The Wal was made in civil and military versions. They chose the military version as its empty weight was lower than the civil and it was easier to convert to a long range machine with extra fuel tanks located in the fuselage, below the engine nacelles. A significant factor in the choice was probably the Rolls-Royce Eagle engines of 380hp each. The name Rolls-Royce was synonymous with quality and reliability. The plan was to have a crew of three in each aircraft. The navigator would occupy the open cockpit in the nose, the pilot in the open cockpit behind the navigator and the mechanic managed the fuel and engine in an enclosed position in the fuselage below the engine nacelle. The Wal was an advanced design and would prove to be exceptionally robust on the 1925 Arctic flight and on other pilot’s long distance flights over water and ice. The Rolls-Royce engines on Amundsen’s Wal started up time after time.
The two Dornier Wal flying boats were shipped to Kings Bay in six enormous packing cases as deck cargo aboard Hobby. They could not dock at Ny Alesund. They were unpacked aboard ship and the components were lowered on to the ice. The engine nacelle is being mated to the fuselage of N 24.
They chose to ship the aircraft to Kings Bay and assemble them there. There were conflicting reports of their intentions; at one point it was reported that they intended to fly from Spitsbergen to the North Pole and on to Alaska. Each aircraft carried fuel for 16 hours flight. The only way they could fly to Alaska would be to land on the ice at the Pole after flying for about eight hours and transfer the remaining fuel from one aircraft to the other. They would then load all six crew members to one aircraft and take off with 16 hours fuel and fly on to Alaska. Eventually they decided to fly from Kings Bay to the North Pole and back to Kings Bay. In late 1925 (after the flight of that year), Amundsen wrote:
‘Our hope to get right along to the Pole was very small, for that, our radius of action was too limited. Apart from that I had not any great interest in reaching the Pole, as I had always regarded Peary as being the first on the spot.’
The general understanding of the aims of the flight was that it was to be to the Pole and back. There is no evidence that they intended, when they took off, to fly to a point South of the Pole and then turn around with enough fuel for a non-stop return. They aimed for the Pole but were shy about how they were going to do it. The explorers always gave the impression that they might have to land and transfer fuel from one aircraft to the other but in fact this would be inevitable. The realities of endurance, range, navigation weather made it so. The Wal had an endurance of 16 hours at an airspeed of 81 knots giving a range in still air of 1,296nm. The distance from Kings Bay to the North Pole and return is 1,330nm. The figures are not far apart but in reality the endurance and range required to fly to the Pole and back were far in excess of the aircraft’s capability. With no wind and perfect navigation the Wal could not complete the flight before running out of fuel. The true situation was even worse because flight planning for long distance flights have to assume some adverse wind. In 1925 air navigation was an evolving art and some inaccuracy in navigation was to be expected. A five per cent allowance for adverse winds plus a further five per cent for small cumulative errors in navigation and five per cent for a reserve increase the range and endurance required to 1,530nm and 19 hours. It followed that there was no chance of a return flight without landing to transfer fuel and crew and abandoning one of the Wals on the ice. This basic fact would make the flight a near death experience for all concerned.
Amundsen appointed Hjalmar Riiser-Larsen as the expedition’s second in command and relied on him to arrange the technical matters. After going to sea in merchant ships as a teenager, Riiser-Larsen had entered the Norwegian Naval Academy at Horten, near Christiania, as a 19 year-old cadet in 1909. He was commissioned into the Royal Norwegian Navy in 1912 and was promoted to First Lieutenant in 1915. He joined the Royal Norwegian Naval Air Service 1915 and ultimately became proficient in flying both land planes and seaplanes. He was inspector at the Naval Aircraft Factory 1916–1919 and had flown in Great Britain and Germany to broaden his experience and select aircraft for Norway. On 13–14 July 1922 he flew a Hansa-Brandenburg seaplane from Kristiania to Kirkenes near the Finnish border and back, a distance of around 1,950nm in less than 48 hours.
Riiser-Larsen’s first airship flight took place in 1919 in the German civil Zeppelin Bodensee and in 1921 he was sent to Great Britain to train as an airship pilot. His training included flying in captive balloons (kite balloons), non-rigid and rigid airships and ground school covering the theoretical aspects of lighter-than-air flight. He should have made flights in free balloons but none were available. He had been sent to Great Britain because the British government were planning an airship airline to link London with Stockholm and Copenhagen and Norway wanted Oslo to be included in each round trip. They also wanted Oslo to be the first stop on the flight from London. His superiors instructed him to lobby General Edward Maitland (who was playing a major part in the project) while he was receiving instruction. Brigadier-General Edward Maitland had joined the British Army in 1900, served during the Boer War (1899–1902) in South Africa and taken up ballooning in 1908. He was aboard the balloon Mammoth in 1908 when it flew from England to Russia, covering 970nm in 36½ hours. In September 1911 he was awarded Federation Aéronautique (British Empire) airship certificate N.8. He served in the Air Battalion, the Royal Flying Corps, Royal Naval Air Service and the Royal Air Force. He was aboard R 34 during its double transatlantic crossing in 1919. Maitland was a keen golfer and Riiser-Larsen agreed to receive golfing instruction so that he would have time alone with Maitland. He produced meteorological records which supported his contention that Oslo would be an appropriate port of call and that Oslo should be the first stop but the service was never started. Maitland was one Riiser-Larsen’s instructors. When Maitland wished to get back to the office he would direct the airship back over the landing ground and parachute from it. An enthusiasm for parachuting was a very rare thing in the early 1920s. Maitland was killed when the new rigid airship R 38 broke up in the air and burnt on 24 August 1921. Another instructor was Major Scott. Major George Herbert Scott was a major contributor to the British airship programme as both engineer and pilot. Scott trained as an engineer and worked in both Great Britain and Spain before the Great War. He joined the Royal Naval Air Service in 1914, trained as an airship pilot and flew non-rigids before being appointed as Captain of HM Airship No. 9, the first British rigid airship to fly. After the war he commanded R 34 on its double crossing of the North Atlantic which took place 2 July to 13 July 1919. The east to west leg was flown on 2–6 July 1919 against the prevailing westerly winds and took 108 hours. On 10–13 July 1919 the west to east leg was flown in 75 hours. R 34’s average groundspeed west bound was less than that of the fastest contemporary ocean liner over the same track.
Riiser-Larsen with the Goerz drift meter fitted to both Wals. When there was a clear view of the surface it could measure both drift and groundspeed. The navigator used the information to update his dead reckoning.
In the early days of aviation in Norway it was common for military pilots to do some civilian flying from time to time and Riiser-Larsen was no exception. He was probably the most experienced aviator in Norway at the time of his appointment by Amundsen. Riiser-Larsen was tall (6’ 4°) and strongly built and aged 35 in 1925. His combination of physical strength, endurance and piloting skills saved his life and those of his companions during the 1925 expedition. He had visited the aircraft factory at Marina di Pisa to liaise with the manufacturers and inspect the Wal flying boats during their construction. He had to return home when Amundsen went bankrupt but returned to the factory when Ellsworth’s money became available. He played a crucial role in organising the expedition by liaising with Amundsen, SCMP (Societa di Costruzioni Meccaniche di Pisa; the aircraft manufacturers) at Marina di Pisa in Italy and the Norwegian Luftseiladsforening which was in overall charge of the expedition. As well as supervising the construction of the specially modified Wals, he had to select the flight and navigational instruments which were to be installed in the flying boats. Amundsen wrote this about Riiser-Larsen:
‘Hjalmar Riiser-Larsen had already taken part in the spring attempt to get the expedition going, so he quite familiar with everything. It was therefore both with gladness and with trust that I was able to telegraph to him the $85,000 – James W, Ellsworth’s [Lincoln Ellsworth’s father] gift – asking him to order the two seaplanes. From this moment Riiser-Larsen got permission for leave and was able to give himself up entirely to the expedition. As a flying man he is so well known by every person in the land that it is superfluous and stupid to mention more. But he has dozens of other notable qualities which I need not enumerate and which made him specially qualified to fill the post he has. With such a second in command a difficult trip becomes for the leader a pleasant and light effort’.
The other pilot was Leif Ragnar Dietrichson who had attended the Naval Academy in 1908–11 before going to sea as a mate with the Bergens Steamship Company and serving in the Navy from 1914 onwards. He transferred to the Royal Norwegian Naval Air Service when it was established in 1915. He learnt to fly in 1916 and took further instruction in Great Britain in 1918, being appointed Chief of the flying boat base at Kristiansand in that year. He continued in that position, surviving a crash into Portør harbour in 1919. Amundsen wrote this about him:
‘His skill as a flyer is recognised by all. His bravery and resolution will stand out clearly……With his light outlook on life, his glad smile and happy nature, he was an invaluable comrade on the flight.’
A third naval aviator was appointed although he flew as a mechanic and reserve pilot. This was Oskar Omdal who had been with Amundsen in the United States and Alaska during the expedition of 1922–23. And Amundsen wrote:
‘If things went with him or against him it was all the same. Nothing seemed to depress him. He stood beside me in my two unhappy attempts in 1923 and 1924, and you can believe that it took a real man to show courage and keenness in a third attempt, but Omdal did not disappoint me’. “So long as you don’t give in”, he said to me, “you shall always find me ready”. He is a marvellous being; he seems to have several limbs more than the rest of us. He moves slicker and thinks quicker. It is impossible to depress him’.
In the book Amundsen wrote (with contributions from other members of the expedition) in 1925 he defined the expeditions aim as being to:
‘Trek in as far as possible over the unknown stretch between Spitsbergen and the Pole to find out what is there or what isn’t there’.
Harald Sverdrup was still aboard the Maude in the summer of 1924 and he had sent a telegram to Amundsen indicating that his tidal observations indicated that it was unlikely that there were any large tracts of land north of Alaska.
It is reasonable to assume that before the flight a major aim was to make the first flight to the Pole as well as well as put a swath of the Polar Ocean on the map. If, as seemed likely, there was no land to be discovered, they could at least confirm its absence.
Amundsen meet up with Riiser-Larsen at Marina di Pisa where Riiser-Larsen oversaw the preparation of the aircraft for the flight. One of Amundsen’s biographers wrote that:
‘The lieutenant was the expert, the polar explorer the fantasist’
This is fair comment given that Riiser-Larsen’s experience and expertise in aviation was in marked contrast to Amundsen’s. Riiser-Larsen was a man whose professionalism in all aspects of aviation equalled Amundsen’s in all aspects of Arctic exploration by surface travel. The problem was that Amundsen was expedition leader whose decisions were final while Riiser-Larsen was second in command and this may account for some of the shortcomings of the plan they acted on. On 25 February 1925 the two men left Italy by train having left instructions that the Wals were to be crated and sent north by ship. After a stop in Berlin the explorers arrived near the Norwegian capital (now called Oslo) on 4 March. Riiser-Larsen travelled on alone to deal with the crowds. The fact that Amundsen was constantly plotting to avoid crowds of curious citizens and journalists is testimony to his fame and the intense interest in his expeditions. The fact that the expedition would use leading edge technology (aeroplanes) only added to the interest. Amundsen would have acknowledged that he sought fame, as it helped him raise money for his expeditions, and that he enjoyed the limelight most of the time. He would not have been human if he thought (like the English playwright and wit Oscar Wilde) that ‘the only thing worse than being talked about is not being talked about’. On 11 March a telegram was received advising that the planes had left Marina by ship on that day.
On 30 March Ellsworth arrived in Oslo by ship and on the day before their departure he and Amundsen attended a dinner held in their honour. At 18:30 they were seen off from the East Station by a large crowd of well-wishers and journalists. On 9 April 1925 the Expedition and its equipment departed Tromso bound for Ny Aalesund on Kings Bay. The ships were the motor ship Hobby (carrying the aircraft as deck cargo in six huge crates and 21 smaller containers) and the naval vessel Farm (not to be confused with the famous Fram) which had been placed at Amundsen’s disposal. It was early in the season and Amundsen had some anxiety over the dangers of the voyage including ice and bad weather. After a stormy voyage, during which the ships had lost sight of each other, the ships arrived at Ny Aalesund to find the bay iced over. Another ship cut a channel through the ice so that the expedition ships could approach the shore. They moored near the coal company’s jetty and began unloading the aircraft. With the expedition were Schulte-Frohlinde (director of SCMP), his two mechanics Feucht and Zinsmayer, and Rolls-Royce mechanic Green. All of them helped to get the crates ashore and the Wals assembled and ready for flight. There were two meteorologists with the expedition and they collated radio reports of the weather information from places around the margins of the Polar Sea and prepared weather forecasts. Amundsen particularly appreciated the work of sail-maker Ronne who prepared everything from trousers to sleeping bags and tents. Ronne gave Amundsen a large knife which proved to be invaluable when the ice runways were being prepared on the ice at 88° north. During the stay at Kings Bay the Expedition made itself comfortable and looked forward to Fridays when they could use the bath house with its boiler fired by coal from the mine. Amundsen biographer Tor Bomann-Larsen wrote of Ny Alesund that it was ‘entirely taken up with Pole fever’ for those few weeks in the spring of 1925.
Sea ice was still a problem this early in the season and on 29 May Farm had to turn back when it attempted to sail to Green Harbour (on Spitsbergen about 50nm south of Kings Bay) to deliver and pick up mail.
Amundsen also had decisions to make about an expedition to be mounted in 1926. Riiser-Larsen had the information that the Italian semi-rigid airship N1 could be purchased for $100,000. It had always been assumed that a large airship would cost more than they could raise. Ellsworth offered to put up the money and it was decided to negotiate the purchase and organise the expedition as soon as the 1925 flight was completed. The 1925 flight now became less important and was represented as reconnaissance towards the North Pole rather than attempt to fly to the Pole and back.
A fuselage being towed across the ice of Kings Bay from the Hobby to land at Ny Alesund.
The two Dornier Wals were assembled in the open at the mining settlement of Ny Alesund as photographers took still and motion pictures for the book and documentary film about the expedition.
The preparations were marked by the attention to detail that Amundsen applied in all of his expeditions with a precise plan for food for each man for each day and the contents of each man’s rucksack. It was intended that each man would have equipment and food for about a month on the ice. There were pistols and rifles to shoot game and for protection if they encountered polar bears. They carried gear for a surface journey across the ice including skis and collapsible sledges and boats. Riiser-Larsen and Dietrichson had to allocate time to instruct Amundsen and Ellsworth in air navigation as they (the pilots) would be fully occupied with flying. Amundsen taught Ellsworth to ski as this would be an essential skill if they had to trek out from a landing on the ice. Amundsen and Ellsworth each had three chronometers and checked them against the radioed time signal from the Eiffel Tower every day for 14 days because their accuracy was essential for accurate navigation. There were three chronometers so that they could be checked against each other. Another essential for navigation were sextants to measure the angle between horizon and the sun. An aircraft sextant should have an artificial horizon built into it so that it could be used if the horizon was indistinct or invisible. The sextants they had were defective in that this feature did not work. They had ordered radio sets for each aircraft but they had not arrived. The radios could have been used to supplement the onboard navigation by taking bearings on the radio stations afloat and ashore at Kings Bay. Amundsen and Ellsworth elected to go in the knowledge that navigation would be problematical and that they could not summon help if they could not make the return flight.
Feucht, Riiser-Larsen and Amundsen aboard N 25 just before take-off on the flight towards the North Pole.
On 9 May the N 25 was ready and taxied on the ice of the bay although neither aircraft was flown before they departed for the Polar flight. The day of departure for the Pole would be the first and only time that the Wals would take off with a full over-load. Amundsen met with Ellsworth, Riiser-Larsen and Dietrichson in late April and announced that he intended to over-fly the Pole and fly in to Alaska. Ellsworth’s aircraft would return to Kings Bay. In this he was re-enacting his famous announcement at Madeira in 1910 that Fram was not going to the Arctic Ocean and the North Pole but on to Antarctica and the South Pole. The difference here was that he did not possess the expertise to assess the risks the journey would involve. The distance from Ny Alesund to the North Pole and on to Wainwright, Alaska was over 1,800nm and the range of a Dornier Wal was about 1,300nm, even if no allowance was made for wind, navigational issues and a reserve. Riiser-Larsen and Dietrichson vetoed the plan (for perfectly good technical reasons) and Amundsen had to agree, grumbling in his diary:
‘I ask myself so often, where are the guts? If they are the slightest bit uncertain, they pull in their horns’.
Amundsen in the front cockpit of Dornier Wal N 25 shortly before departure from Kings Bay late on the afternoon of 21 May 1925. From left to right are; the windshield of the pilots cockpit, sun compass, airspeed indicator and venturi which was used to drive the gyroscopic instruments used in blind flying. The sun was low throughout the flight and ‘blinkers’ were placed behind the clear windshields of both cockpits as soon as they reached cruising altitude. The two Dorniers would have the sky to themselves and so there was no risk of collision as long as the Wals kept to a loose formation with a clear view of each other.
Dietrichson and Ellsworth in their cockpits waiting to take-off late on 21 May 1925.
On 21 May 1925 the aircraft and the men were ready and the weather and ice conditions were suitable for the take-off. The plan had always been dependent on the ice in the Bay being strong enough for the flying boats to take off from. The machines were overloaded and if the Bay had been ice free they would have been so low in the water that they could not have accelerated enough to get ‘on the step’ and could not have taken off. The normal maximum takeoff weight was 5,700kg and the Wals were loaded to 6,660kg, and overload of almost 1,000kg.
At 17:00 they were ready for departure with the engines warmed up and the final details attended to. The crew members donned or made ready the special clothing and footwear that was necessary for long flights in open cockpits in sub-zero conditions. The mechanics were protected from the slipstream in their enclosed positions and needed to move around to manage the fuel and engines and so were less warmly clad than the observers and pilots. The sun compasses were set going final goodbyes made and the machines taxied down the ramp and onto the ice of the bay. In N 25 were expedition leader and navigator Amundsen, pilot Riiser-Larsen and mechanic Feucht. In N 24 were Ellsworth, pilot Dietrichson and mechanic Omdal.
The N 25 made its take-off first with the ice bending beneath its weight and the sea water surging up as it made its run with both engines running flat out at 2,000rpm. After a tense 40 or 50 seconds Riiser-Larsen eased the wheel back and the machine took to the air. Dietrichson in N 24 had a more eventful take-off. In turning through 90° on to the slipway (with the help of some of the men watching the departure) the pilot heard a sound like a row of rivets popping and, sure enough, when he slowed down in the middle of the Bay so the crew could don their cold weather gear, the ice sank beneath machines weight and the hull started to fill with sea-water. They hurriedly finished dressing and made a full throttle dash across the ice with Dietrichson letting the air speed rise to 65kt before pulling back on the wheel to rise into the air. The take-off had taken 1,400m.
Amundsen biographer Tor Bomann-Larsen wrote of Ny Alesund that it was ‘entirely taken up with Pole fever’ for those few weeks in the spring of 1925. The two Dornier Wals surrounded by onlookers at Ny Alesund just before take-off on 21 June 1925.
The two Wals flew in loose formation up the western coast of Spitsbergen, passed Danes Island and Amsterdam Island off the North Western point of Spitsbergen and made their departure for the North Pole. The mean temperature during the flight was about –13° and the airspeed was around 80kt giving a substantial wind-chill factor if they had to expose any part of their bodies to the slipstream. The clothes and footwear had been carefully chosen and cold was not a problem. They were facing the low sun and even dark sun glasses did not make for comfortable vision. They had anticipated this problem and they installed shields called ‘blinkers’ behind the windscreens in the bow and pilots cockpits in each machine. As long as they kept the formation loose there was no risk of collision.
The expedition was the most exciting event in the history of the mining settlement which had been operating at Ny Alesund since 1916. The miners show a close interest in one of the Dornier Wals as it waited to take-off. When Amundsen returned to Kings Bay in 1926 he found a monument to the men of the 1925 flight.
The Dornier Wals were overloaded with three crew, survival gear and fuel and oil for 16 hours flight. The also carried both still cameras and motion-picture cameras to document the expedition. The Dorniers were able to take-off and land on water, ice or packed snow. Here N 25 gets a push from the onlookers as it slides down the ramp onto the frozen surface of Kings Bay. N 25 was crewed by Amundsen as navigator, Riiser-Larsen pilot and Feucht as mechanic. Feucht was a last minute choice and had no experience in the Arctic.
As they flew north Amundsen tried to take a sun sight with his sextant. The horizon was indistinct. This should not have been a problem because they had ‘bulb sextants’ which provided an artificial horizon. They had discovered at Spitsbergen that these sextants did not work and had chosen to depart knowing that, if the horizon was indistinct, they would not be able to determine longitude. Latitude was easier to calculate and Amundsen kept track of it without too much trouble. They were over cloud cover so they could not use the drift-meter to determine their drift or ground speed. The horizon was indistinct so the sextants could not be used. Dead reckoning gave them a general idea of their position but could not provide a fix. Wind was probably drifting them to the west or east of their track. The sun compass and the magnetic compasses gave them a reliable heading and they continued to maintain a heading of due north.
Early on in the flight cloud ‘thick clouds and fog’ made them climb to over 3,000ft to stay in the clear air. Shortly afterwards Dietrichson noticed the engine radiator temperature gauge showing a rising temperature and rang the bell which summoned Omdal. He later wrote:
‘The indicator had passed 100°, and I felt sure that we would have to make a forced landing. Through small holes in the fog we could see the drift ice below us where a landing would certainly mean a wrecked plane. The temperature rose higher and the last I saw was, that it indicated 115°, when the thermometer burst, and my hopes sank to zero. I rang again for Omdal, but a little time elapsed before he came, and I judged that he was busy. Meantime I was astonished to see that the engines still went as well as ever. I had throttled them down to 1600 revolutions, but expected to hear a crack any minute; and how goes it with the forward motor?’
The engines continued to run and the flight continued with the Wals flying in a loose formation. As he flew Dietrichson thought about the conflicting advice they had received about whether or not they would find places suitable for landing both the Dorniers:
‘Nobody had so far observed the conditions from a flying man’s point of view. This we were quite clear about, but we depended on the material at our disposal, namely our flying boats, which if the worst should happen, ought to be able to take us back home without our making a landing.’
This is a curious observation to make because a return without landing and with a small reserve of fuel and endurance could only happen if they had agreed, before take-off, to turn around at some defined point short of the Pole. They had taken off without agreeing to do this. By default, they set out knowing that landings would have to be made and that they were hostages to fortune. At about 82° north they flew out of the fog belt and could again see the surface. They flew at altitudes varying from 3,000ft to 10,000ft (about the service ceiling of a Dornier Wal) and looked carefully for land. Of land there was no sign. Their view of the surface was not reassuring. Dietrichson noted:
‘The ice looked quite different to what I expected. Instead of the big kilometre ice plain, we saw ice plains which through cracks or bergs had been divided into small, irregular pieces, where it was impossible to land. And open water lanes? These were reduced to small snake-like cracks, following a winding course, on which it was impossible to land…. Hour after hour passed without the conditions below use changing to any noticeable degree.’
After about eight hours, when they should have been in the vicinity of the Pole, depending on the wind direction and strength (they had been unable to get a fix on their position during the flight) they saw blue water rippling in the sunshine, the first seen since leaving Spitsbergen. They had planned to land on the ice if at all possible but the ice was broken and quite unsuitable for a landing so N 25 descended towards a lead. As Riiser-Larsen reduced power the rear engine started to back fire and loose power. He was obliged to land in a lead full of slush and small pieces of ice which at least slowed N25 down. Amundsen saw one of the wing-tips pass over the top of an iceberg close enough to blow off some loose snow:
‘We zig-zagged along in a manner which was most impressive and alarming…I expected every moment to see the left wing destroyed. The speed now slackened in the thick slush, and we stopped at the end of the arm-nose up against the iceberg. It was again a question of millimetres. A little more speed and the nose would have been stove in.’
The lead was too small for both machines so Dietrichson found another one and landed. As soon as he throttled the engines back the rear engine stopped but he was able to land safely. As soon as he was down he taxied to a small berg, and as far up it as he could, so that the N24, with its sprung rivets, would not sink.
Conditions on the ice were fluid. Ellsworth later wrote:
‘The danger of being crushed became apparent…a north wind tended to open the leads. On the second day, though, it shifted to the south, and we could see the ice closing in. The whole field was alive with inert motion. Ice cakes in the lead would disappear, as if sucked under; others would emerge to the surface. The edges of the lead drew imperceptibly closer to each other. The implacable jaws were shutting on us, and we all felt that our plane would soon be caught in them’.
Soon after landing Dietrichson and his crew saw a seal, the only sign of life that they would see during their stay on the ice. They would soon regret not having shot it for its meat.