Updated: Oct 20, 2019
During its relatively short history (just 34 years) BOAC operated no less than forty-three different types of aircraft. When formed in 1940, they had inherited the combined fleets of Imperial Airways and British Airways Ltd (an early forerunner of the present British Airways). The result was a mixed bag of flying boats, modern American aircraft including the Lockheed Electra, and a significant number of obsolete airliners from an earlier era. These included such relics as the Armstrong Whitworth Atlanta, a ponderous four-engined design which had first flown in 1932 and carried only nine passengers at 115 mph! Thirty-seven years later BOAC pilots would be test-flying Concorde at supersonic speeds.
Throughout the Second World War any number of military aircraft were ‘civilianised’ and transferred to BOAC, although ‘civilianisation’ rarely meant more than removing the guns and turrets. Many of them were poorly suited to the tasks of flying VIPs, troops and material over long distances and into parts of the world where there were few facilities and even fewer spare parts. The most remarkable however, must surely have been the de Havilland DH-98 Mosquito. In 1943 it was the fastest and probably the most versatile aircraft in RAF service.
The original idea for the Mosquito had come from de Havilland themselves as soon as 1938. They based the design on their earlier DH-88 Comet, which won the 1934 London to Melbourne air race and is still considered to be one of the most beautiful aircraft of all time (the original DH-88 survives to this day and is still flown by the Shuttleworth Collection). De Havilland’s concept was simple: build a light aircraft with two Rolls Royce Merlin engines whose defence would be its speed and manoeuvrability. In order to reduce weight, it would be constructed largely from wood laminates - a material which de Havilland had extensive experience of.
The aircraft’s phenomenal speed and manoeuvrability meant that Mosquitos were rarely shot down by the Luftwaffe. In fact, so valuable was the Mosquito that the Air Ministry would have needed a very good reason indeed to divert precious airframes away from the military and give them to what was ostensibly still a civilian airline.
The rationale was clear: one of BOAC’s most vital tasks throughout the war was to maintain air services to neutral countries, and among the most important of those was the route to Sweden. Before the war, British Airways Ltd had already been operating a weekly service to Stockholm. When hostilities broke out and Norway was occupied, this was changed to a new route via Perth and Helsinki using Lockheed 14s. The direct Stockholmsrute, as the Scandinavians called it, was originally set up by the Norwegian Government, exiled in London, to rescue Norwegians who had escaped from Nazi-occupied Norway and bring them to Britain. Several types of aircraft were used, but the route was mostly flown with Lockheed Lodestars operating from Leuchers in Scotland. As well as escaping Norwegians, Sweden also produced high-quality ball bearings which were vital to the war effort and the route was quickly nicknamed by the British, the ‘ball bearing run.’
The civilian Lockheeds were soon replaced with ex-RAF Hudson aircraft, but they were vulnerable to German fighters and when the Swedes had two of their own DC3s shot down during flights to Britain, minds were concentrated on finding a faster alternative. Some interesting conversations must have taken place at the Air Ministry and elsewhere. The Mosquito was arguably the most valuable aircraft that the RAF then possessed, and its complex, bonded wooden structure meant that they were not easy or quick to build. On the other hand, the government considered that maintaining the air route to neutral Sweden was vital and it was that argument which finally won the day.
The de Havilland Mosquitos, painted in BOAC colours and flown by pilots in BOAC uniforms, began flying to Stockholm in 1943 during the short summer nights and periods of the Aurora Borealis. Their crews must have seen some spectacular views which would probably have been cold comfort given the risks they were taking. The specially lightened aircraft operated at very high altitude, over 35,000 feet, which meant they could overfly German-occupied Norway where they were too fast and too high to be caught by conventional German night fighters. The exhaust shrouds had been removed from the Merlin engines, adding around 30 miles per hour to the Mosquitos already considerable speed. The Germans responded by fitting some of their JU 88-night fighters with GM-1 nitrous-oxide injection which significantly increased their speed, but they never succeeded in shooting down a BOAC Mosquito.
The Mosquitos carried mail, diplomatic baggage, as well as gold ingots and Sovereigns which were used to pay for the ball bearings. Incredibly, they could also carry a single passenger in the aircraft’s bomb bay! The passenger, once airborne, was completely unreachable by the crew of two. They would simply be given a parachute, an oxygen mask, a flask of coffee and some blankets to protect them from the cold!
One of the most important passengers was the notable Danish scientist Niels Bohr who was an expert in atomic research. When Bohr learned that the Germans planned to arrest him, he fled to Sweden from where a BOAC Mosquito brought him to Britain. During the flight, Bohr took off his uncomfortably small flying helmet and consequently failed to hear the pilot's instruction to turn on his oxygen supply as the aircraft climbed to high altitude over Norway. He lost consciousness from oxygen starvation and only woke up when the aircraft descended to lower altitude over the North Sea. The pilot, having heard no sound from the bomb bay for some time, had guessed what had happened and saved Bohr’s life by descending.
In what must have been the most unusual service ever undertaken by BOAC a total of thirteen Mosquitoes were operated, of which five crashed (none from enemy action) with several pilots and radio operators losing their lives. Between 1939 and 1945, 6,000 passengers and 500,000 tons of freight were transported between Stockholm and Great Britain.