Sci&Tech Editor Peter Amor explains how the strong winds of storm Ciara boosted a transatlantic flight to record-breaking speeds
Ever since Alcock & Brown flew a repurposed World War 1 bomber from Newfoundland to Ireland in 1919, advances in aviation technology and weather prediction have allowed steadily faster transatlantic flights. Progress has been swift; in the 1930s, Britain’s Imperial Airways and America’s Pan American Airways competed to be the first to go direct from Great Britain to America with passengers, while in the 1950s, the advent of the jet engine allowed a much faster regular service.
Among all the chaos caused by the recent Storm Ciara, another achievement in the transatlantic flying business went almost unnoticed. Aided by strong winds, a British Airways Boeing 747 broke the subsonic transatlantic flight record, travelling from New York to London in a mere 4 hours and 56 minutes.
During the flight, the aircraft reached speeds of 825 mph, or 1,327 km/h. This may sound like cheating; after all, the speed of sound at 30,000 ft is 678.1 mph, so on paper it sounds as if the aircraft was actually supersonic (faster than the speed of sound). However, this ignores the distinction between airspeed (how fast something moves relative to the air) and groundspeed (how fast something moves relative to the ground). Here, the air in which the aircraft was travelling was itself moving at over 200 mph, hence the high speed.
This was possible due to the Jetstream, an area of strong west to east winds present at around 5 to 7 miles above the Earth. These are frequently used by aircraft travelling across the atlantic, which is why it is usually quicker to go from America to Europe, not the other way around. Storm Ciara intensified the winds, and led to the strong winds this flight took advantage of.
It is not true to say, however, that this is the fastest flight ever across the Atlantic. In fact, it is not even the fastest commercial flight; that honour belongs to another British Airways aircraft, the supersonic Concorde. On 7th February 1996, this Anglo-French engineering marvel covered the New York – London trip in 2 hours, 52 minutes and 59 seconds, equating to an average speed of 1,250 mph, or 2,010 km/h. Although at the moment unlikely to be bettered, various startups including Boom and Aerion Supersonic are developing supersonic airliners that could threaten the record.
But what about non-commercial aircraft? Surprisingly, over twenty years before Concorde’s attempt, another aircraft had covered the distance in less than two hours; this being the Lockheed SR-71 Blackbird. The Blackbird was a high-altitude, high-speed reconnaissance aeroplane, designed to gather intelligence over the Soviet Union during the Cold War. To avoid being shot down, the aircraft would have to travel at 3 times the speed of sound, which required a number of rather radical features. For example, the aircraft was made almost entirely of titanium alloy, and its windscreen had to be coated in quartz, in order to deal with the intense heat at high speeds. Further, like most jet engines, the SR-71’s engines needed the air travelling into them to be subsonic (slower than the speed of sound), necessitating complicated cone-shaped air intakes that adjusted in flight. All of this aided the aircraft during the record run, on September 1st, 1974, when New York to London was covered in just 1 hour, 54 minutes and 56.4 seconds, equating to an average speed of 1,806 mph, or 2,906 km/h.
Does this mean that we’ll all be travelling supersonic in the future? Unfortunately for lovers of speed, the answer is probably not; supersonic commercial flight is currently beset with environmental, practical and economic problems, whether they be from sonic booms, high fuel consumption (Concorde burned 2 tons of the stuff just taxiing to the runway) or severely limited seating capacity. We wait with baited breath to see further developments in this field.