After her modification for scientific research, Aries sits at a Canadian airport in 1945. Inset: Wing Commander Kenneth Maclure.

In the closing months of World War II the Empire Air Navigation School, Shawbury, Shropshire, was more than a school; it was a centre for research into the problems, techniques and tools of aerial navigation. Two particularly outstanding officers were wing commanders David Cecil McKinley of the Royal Air Force, and Kenneth Cecil Maclure of the Royal Canadian Air Force who had been studying the problems of navigation in Arctic regions since 1942. Maclure in particular had worked out a method he dubbed the “Greenwich Grid System” by which all headings and readings were calculated relative to the prime meridian. His interest in the subject was appropriate; in the 1850s his ancestor, Robert Maclure, had been engaged in the Franklin search which also traced the elusive Northwest Passage.

Late in 1944 a Lancaster bomber was offered to the school for research flying; McKinley and Maclure proposed to the air ministry that an aerial expedition be launched to study polar flying. The resulting flights, coming immediately after VE-Day when military censorship was being relaxed, were widely publicized. They also heralded the future of peacetime aviation, with special emphasis on the North Atlantic air routes soon to be opened to commercial operators.

Lancaster PD328, named Aries, was a very special machine. Built as a standard Mark I bomber, it had completed a round-the-world flight in 1944 as part of RAF preparations to deploy heavy bombers to the Pacific theatre once Germany had been defeated. Her pilot on that occasion had been McKinley, who was awarded an Air Force Cross for the mission. In April 1945 the aircraft was modified extensively. All armament and armour were removed; camouflage paint was replaced by a glistening metal finish; the fuselage was altered for streamlining and the fuel capacity expanded, increasing maximum range to 5,000 miles or about 21 hours continuous flight. Most important of all was the scientific array added, including 11 different types of magnetic compasses distributed throughout the aircraft.

Yet it was impossible to solve all potential problems; Aries had been designed as a bomber and that imposed limitations. Space was limited and crew comforts could only partly be accommodated. Wing Commander R.H. Winfield, medical officer of the expedition, wrote of some difficulties: “During the flights, one of the major problems was to keep warm the observers working in the fuselage. In the standard Lancaster, the crew are placed either in the cockpit towards the nose of the aircraft or in the gun turrets. Those in the cockpit are warmed by an efficient hot-air system of cabin heating, while the gunners wear electrically heated suits. The fuselage is uninhabited, and heating is not required. When the Aries was converted from heavy bomber to flying laboratory, it was not possible to warm the fuselage; and since the generators were already loaded to their full capacity to provide current for the scientific equipment, the observers in the fuselage could not use electrically heated clothing. In fact, it became so cold that after spending an hour in the fuselage, it was necessary to go forward to the cockpit for about five minutes in order to thaw.”

Preparations included mock flights in a device called the Celestial Link Trainer–the most advanced flight simulator of the day. Existing records of Arctic navigation and flying were studied. Winfield sought out suitable clothing, food and survival equipment; clothing in particular had to allow freedom of movement in a cramped aircraft, had to be cool enough to avoid overheating, yet give protection in the event of a parachute descent or emergency encampment awaiting rescue. Prior to departure the crew lived two days in a refrigerated chamber eating dehydrated meals.

The Aries expedition was given several tasks–to test Maclure’s theories of grid system navigation, search for the North Magnetic Pole, identify problems associated with Arctic flying, assess performance of existing instruments, collect weather data, investigate possible radar mapping of icefields, observe effects of polar flying on aircrew, and collect engine and airframe data. Nailing down the position of the Magnetic Pole was important because its position had shifted since it was last discovered.

Eleven men crewed Aries. They were: Wing Commander McKinley, DFC, AFC, the pilot and officer commanding the expedition; Wing Commander E.W. Anderson, senior navigator and responsible for external observations needed to plot position such as astral bodies; Wing Commander Maclure, senior observer and responsible for collecting magnetic, radar and other special data outside of navigational observations and the co-ordinator of research; Wing Commander R.H. Winfield, DFC, medical officer and assistant of Maclure; Squadron Leader A.J. Hagger, co-pilot, meteorological observer and photographer; Flight Lieutenant S.T. Underwood, navigator/plotter, responsible for maintaining a continuous record of the aircraft’s position; Flying Officer S. Blakeley, wireless operator; Warrant Officer A.S. Smith, wireless operator; Corporal W.S. Gardner, airframe mechanic; Leading Aircraftman E.M. Wiggins, aero-engine mechanic; Leading Aircraftman H.J.B. Dean, electrician.

Those organizing the expedition would have preferred winter flying; with the Arctic shrouded in darkness, precision navigation could have been performed using astral readings. Preparations for the operation had delayed it until spring. Timing thus assumed great importance; for this navigational exercise there were only five or six days each month when the positions of moon and sun met the necessary conditions (northerly declinations, separated by at least 60 degrees). Even that time window narrowed to two days per month over the summer, not increasing again until September. The expedition began May 10, 1945–ironically, the centennial date of another departure from Britain, that of Sir John Franklin’s two ships, bound for tragic fame in the Northwest Passage.

The first stop was at Meeks Field, Reykjavik, Iceland, from whence they intended to sortie over the North Geographic Pole. The weather was unco-operative; the aircraft was heavily loaded with fuel and instrumentation and could not risk heavy icing. Early on the morning of May 16 they took off, intending to run up the northeastern coast of Greenland and the 10th meridian to the pole. Cloud and icing developed, forcing a return to Reykjavik. They had been airborne nine hours and accomplished nothing.

Weather reports suggested that a different route, further east of the earlier track, might be better. McKinley decided to try again as soon as Aries had been refuelled. Less than two hours after landing, the aircraft was off again. This time they struck northeast, passing Jan Mayen Island on its eastern side before running north again, roughly along the prime meridian towards a sector in northern Greenland known as Peary Land. About 200 miles after the northern turn, icing again appeared, lasting an hour before they broke clear of it. However, they had burned off enough fuel that the condition did not present a serious hazard.

Approaching the pole, each man chose a different way to mark the event. Wing Commander McKinley subsequently wrote: “Shortly after 0200 hours on May 17 we were within a few miles of the pole when the navigator called an alteration of course to take us over the top. Quite a lot happened in the next few minutes; the wireless operator off duty began to peel a banana which he had procured in Gibraltar 10 days before, and was preparing to eat it while crossing the pole; the operator on duty was in contact with Reykjavik and was passed a bearing of 000o; and the doctor threw a bottle of beer and the Union flag overboard. Circling the pole before the return journey, we crossed all the meridians in some 80 seconds, and a moment later we crossed the International Date Line for the second time in less than two minutes while going in the same direction.”

The return flight to Reykjavik was uneventful until the last two hours, when they encountered the same icing conditions experienced on the outward run. Nevertheless, all equipment worked perfectly and they touched down after having been airborne nearly 19 hours.

With only three hours sleep after returning from the North Pole, the Aries crew began preparing for the next part of their mission. Only two days remained of the “window of opportunity” to chart the North Magnetic Pole, the position of which was only estimated as being in the vicinity of the Boothia Peninsula, west of Baffin Island. Given that its position was both changing and indeterminate, and its importance significant to aerial and marine navigation, establishing the location of the Magnetic Pole was highly desirable. They departed Reykjavik at 3 a.m. on May 18, intending to fly directly across Greenland to their objective before turning south.

As they began crossing Davis Strait they sustained the only serious mechanical failure of the expedition. An electrical generator bearing failed and the generator had to be shut down. That left one generator to serve all equipment needs. Even if it did not fail, it would certainly deliver diminishing current, compromising the accuracy of scientific readings. Aries turned south, heading for Goose Bay, where they landed at 5 p.m. Racing the clock–the “window” was down to 35 hours–they repaired the generator, charted a revised track, and waited impatiently for suitable weather. Early on May 19, Aries was airborne again.

The outward flight was marked by some minor difficulties–moderate but sporadic icing, failure of the automatic pilot–but the chief problem was the one they had come to investigate. Within 200 miles of the magnetic pole, compasses became more erratic; they were stable in periods of steady flight, but should the aircraft accelerate or slow down, the needles wandered aimlessly. They had still not attained the North Magnetic Pole on reaching their Prudent Limit of Endurance, but the evidence was clear enough that it lay north-northwest of previous estimates. They turned south, running down the east coast of Hudson Bay, finally touching down at Dorval in Montreal.

McKinley was deeply satisfied with results to date; he summed it up as follows: “By May 21 we had thus achieved our two main objects, and had amassed a wealth of information which would take many months to sift. Two of our conclusions were immediate and outstanding; Maclure’s suggestion for high-latitude orientation was a complete success, and a magnetic survey from the air was perfectly feasible. We still could not say exactly where the magnetic pole lay; of one thing only could we be certain, that it did not lie in Boothia Peninsula.

It was now decided to put their work to immediate and practical work. They would find a base in the northwest of North America, from which they would fly directly to Britain, passing between the North Pole and North Magnetic Pole. The ideal departure point would have been Fairbanks, Alaska, but the plan had been hatched on the spur of the moment, and it seemed quicker to make the flight an “all-Empire” affair than to make special arrangements with American officials.

The Aries crew flew to Ottawa where they conferred with RAF and RCAF senior officers, proceeded to Toronto for a meteorological conference, carried on to Rivers, Man., to visit the RCAF’s Central Navigation School (Canadian counterpart of the Empire Air Navigation School), flew to Edmonton for a final aircraft and weather check, and then travelled to Whitehorse. Describing this final leg, McKinley wrote eloquently: “This was truly wonderful country and we all looked forward to seeing the mighty Rockies on our 1,000-mile journey north. We met nothing but rain, hail, snow and blizzard until we reached Watson Lake far up in the Yukon. Thence, running in under an overcast sky, we saw the northern reaches of the Rockies in all their splendour. Coming in to land at Whitehorse, we rolled down onto the Dominion’s most westerly and certainly one of its most magnificent airfields. A single runway standing on a plateau some 500 feet above the Lewes River, it strangely resembled a giant aircraft carrier hove to in the cold clear light of the western sun.”

The finale of the Aries expedition commenced on the morning of May 25, 1945. Aircraft and crew departed Whitehorse, turning northeast for their homeward run across the polar regions. By now the moon had been lost for navigational purposes; more reliance was placed on radio aids. Apart from some icing and turbulence at the outset, it was an uneventful flight. Nevertheless, important observations were made en route. By 74 degrees North 110 degrees West it was obvious that the North Magnetic Pole lay south of their track, itself 250 miles north of their turning point of May 19–further proof that it was much further north than previously thought. The flight across Greenland indicated that existing maps were very inaccurate; some charted mountains that did not exist; others noted as being 20,000 feet high were only 13,000 high.

Aries landed at Shawbury at 12:45 p.m. on May 26, having been airborne for 18 hours. Over a period of 16 days it had flown 110 hours, covering some 22,400 miles, roughly half of which lay within the Arctic Circle. The crew had accumulated a massive quantity of information–30,000 observations on magnetic phenomena alone.

Virtually every member of the Aries crew received some formal recognition. McKinley was awarded a Bar to his Air Force Cross; Maclure and Anderson received the AFC, Wiggins and Dean the Air Force Medal, while the remaining crew members were commended for Valuable Services in the Air.

The citation to Maclure’s award is worth quoting in full, not only because he was the RCAF’s representative but because his navigational theories had largely inspired the expedition: “Wing Commander Maclure is a navigator and has been employed on navigation test and development duties. He acted as chief research officer during the flights made in the Lancaster aircraft Aries between the 17th and 26th May 1945, involving 110 hours flying, in the course of which a scientific survey was made over the north geographic and magnetic poles. The peculiar problems of navigation at high speed over these regions where, in the extreme case, all directions become south and where traditional methods of orientation by magnetic instruments inevitably fail, have been exhaustively studied by this officer. Over a period of the last two years he has perfected a system of navigation based upon entirely new conceptions of orientation and he has taken the lead in making the necessary technical arrangements by which the accurate execution of these first polar flights of the Royal Air Force were assured. The contribution which he has thus made to the accomplishment of the flights and the scientific data he was able to collect will undoubtedly have far-reaching effects. To obtain his readings, Wing Commander Maclure worked in the virtually unheated rear of the aircraft where temperatures down to 65 degrees of frost were experienced for periods of eighteen to nineteen hours at a time without intermission. Without Wing Commander Maclure’s extreme devotion to duty, the valuable scientific information would not have been obtained. The ingenuity and industry with which this officer has always applied himself to furtherance of air navigation has been most praiseworthy.”

Nor was this the end of his honours. In 1946 he was recognized by the American Institute of Navigation. Maclure remained in the postwar RCAF. His assignments included secondment to the National Research Council. He rose to the rank of group captain before retirement in 1962.

The expedition, then, had been a scientific and personal success. It had been made possible by earlier pioneers, as well as by RAF wartime crews who had developed northern flying in the course of hazardous sorties between Scotland and Russia. At the same time it pointed out new ground, new routes to link continents–and old problems of polar navigation to be solved. A Canadian had been a major player in the Aries flights; Canada as a nation would gradually take a larger role in developing the northern sky trails.