As the number of global travellers soars, our skies are becoming more crowded. Jenny Southan investigates how airspace is being redesigned to deal with demand
Traversing the globe on the highways of the sky can inspire a passion for cloud-spotting – at least for those of us who book a window seat.
Whether it’s ascending through a thick, grey layer of nimbostratus somewhere over the English countryside, looking down on a puffy landscape of stratocumulus, the tenuous brushstrokes of sunset cirrus, or past a formidable mushrooming thunderstorm anvil, these tropospheric manifestations are an everyday wonder we often take for granted.
If you do happen to have taken your eyes off your entertainment screen to admire the aerial tableaux passing before you, it can be a rare sight indeed to see another plane. In “controlled airspace”, aircraft must maintain safe separation (at least three miles apart horizontally and 1,000 feet vertically) to minimise the risk of collision and wake turbulence. (In uncontrolled airspace, for the military, private jets, hot air balloons and microlights, it is often down to the pilot to visually ascertain safe distances.)
And yet, in much of the world, particularly over major hubs, the wide blue yonder is becoming increasingly populated with commercial airliners. Over Europe, 27,000 aircraft pass each other every day; in the US it’s 50,000. In the UK, air navigation service provider NATS handles about 6,000 flights a day – that’s 250 an hour – double what it was 20 years ago, despite a dip during the recent recession.
That’s a lot of planes – still, rather than working towards capping or reducing the number of jets in the skies, the authorities are developing technology and redesigning airspace to allow for even more of them.
John Grant, executive vice-president for the OAG (Official Airline Guide), says overcrowding in the skies is a misconception: “There is no parallel between airspace demand and the M25 on a Friday afternoon,” he says.
“There are peak hours of the day which, when combined with certain meteorological conditions, can put pressure on the system. But the way the space is managed and co-ordinated, and the way that traffic is allowed into airspace, ensures customers are never placed at risk. There is space available.”
EXACT SCIENCE
Paul Haskins, general manager of London Terminal Control at NATS’ air traffic management centre in Swanwick, Hampshire, explains how airspace is organised.
“Every sector has a scientific value that we have calculated to be a safe number for capacity,” he says. “That will differ depending on conditions – the weather, turbulence, thunderstorms and military activity. If a sector starts to get too busy, we might push you to a different one and give you a slightly different routing.”
Traffic is particularly concentrated around the south-east of England, where Heathrow averages 1,300 movements a day, and Gatwick – the world’s busiest single-runway airport – sees one take-off or landing roughly every 65 seconds.
Needless to say, every effort is taken to ensure the men and women working in its control tower are comfortable (no uniform required), distraction-free (visitors can only speak in hushed voices), well rested (there are breaks every 90 minutes) and drug-free (mandatory blood-alcohol tests take place randomly).
Haskins says: “At Gatwick you will see the aircraft are guided by people in the tower looking out of the window, primarily using visual control to make sure the planes are safe on the taxiway. Almost within 30 seconds of being airborne, the flight is transferred to a radar controller based at Swanwick [there is also a Prestwick centre in Scotland], and it will continue on through the sectors.”
In an online video, he goes into more detail: “Our airspace is crisscrossed with well-established airspace corridors that we think of like roads. They are usually ten miles wide and at least 5,000 feet high. Say you were flying from Heathrow to San Francisco – before you arrive at the airport, your airline will have filed a flight plan detailing the route it would like to take. NATS evaluates every plan, working with the airlines to consider factors such as fuelling, traffic patterns and weather conditions to plan an optimum route.
“NATS manages traffic through some of the most complex airspace in the world, covering southern England and the five London airports. As aircraft leave the London area, separation is increased to five nautical miles and their progress is carefully monitored until they reach Scottish or oceanic airspace.
“Next, controllers at Prestwick would give you clearance for your flight to be directed out on to the transatlantic airways. Here, aircraft need to be separated by ten minutes’ worth of distance both in front and behind, and 60 nautical miles side to side. Finally, at 30 degrees west, Canadian air traffic controllers take over.”
CROWD CONTROL
UK airspace, which covers 1.2 million square miles, was first designed in the 1940s and, in its current configuration, is going to reach capacity if demand continues to go up. A new blueprint is therefore required.
The London Airspace Consultation is looking at ways to “revise airspace to incorporate the latest aircraft navigation capability, improve efficiency and reduce environmental impact”.
It is the first stage in a series of proposed changes to deliver the Civil Aviation Authority’s “Future Airspace Policy” for 2030, which aims to improve safety, cut delays and increase capacity, as well as create skies that are simpler to control and allow for more flexibility.
Reforming UK skies is just a small part of the wider problem of how European airspace, which is overly fragmented and highly complicated, is structured.
In total, it covers 4.1 million square miles and is watched over by 60 air traffic control (ATC) centres with 16,900 controllers. Domestic US airspace, on the other hand, covers 3.5 million square miles (plus 24.6 million square miles of international oceanic airspace) and has just 13,000 controllers. In 2010, the European ATM system handled 33,000 flights on busy days, but by 2020 this is expected to rise to 50,000.
According to the European Commission, the cost of such fragmentation amounts to e5 billion a year. The antiquated system means airlines can’t fly the most direct routes, making journey times longer, increasing fuel burn and exacerbating delays.
EU transport commissioner Siim Kallas says that if nothing is done, over the next ten to 20 years airports will become so crowded that two million flights will be unable to take off or land.
The plan, then, is to create a Single European Sky, which will mean fewer ATC centres, a threefold rise in aircraft capacity, a 10 per cent reduction on environmental impact and an increase in safety by a factor of ten.
Jonathan Nicholson, assistant director of corporate communications for the CAA, says: “Isn’t it inefficient that each nation has its own ATC centres so that every time you cross a border you are talking to a different controller? Wouldn’t it make more sense if we had more harmonisation?”
Haskins, however, foresees problems for the Single European Sky. “They want us to come together and move down from 46 to ten or 11 big ATM centres that have inter-operability. If I’m honest, the technology allows us to do that today but the politics don’t. Nobody wants to give their airspace up. I can’t imagine the Daily Mail headline ‘The French are going to take over our airspace’ would be a popular vote winner. We are moving that way, though.”
MILITARY PRECISION
Out of a population of seven billion, 2.5 billion of us fly every year. By 2050, the world will have an extra two billion people. Airbus predicts global air traffic growth to average 4.7 per cent leading up to 2032, but markets such as the Middle East will exceed 7 per cent. When Dubai’s Al Maktoum International hub – set to become the largest in the world – is operating at capacity, it will be processing 160 million passengers a year.
Meanwhile, China is planning to have built 70 new airports by 2015 to cope with projected demand. Boeing recently predicted that the Asia-Pacific region will need an additional 12,820 new planes, representing 36 per cent of new deliveries over the next 20 years.
Randy Tinseth, vice-president of marketing for Boeing Commercial Airplanes, says: “The Asia-Pacific fleet will nearly triple, from 5,090 airplanes in 2012 to 14,750 airplanes in 2032, to support the increased demand.”
Whereas Europe allows for commercial and military aircraft to share airspace, for many countries, no-fly zones are a hindrance. Nicholson says: “The military has a big piece of airspace that is set aside for them to practise in – they might be sending a typhoon straight up at 3,000 feet a minute and firing live ammunition, but they may not be doing that all the time.
“In the UK, we are very good at working with the military and saying, ‘On Tuesdays and Thursdays you’re not using it so we will make it available to commercial airliners.’ In some countries that airspace is permanently shut off, even though you might be able to save hundreds of miles for airliners if you route them through it.”
In China, commercial carriers are battling the military to gain a greater share of its domestic airspace – at the moment, the government has only allotted 20 per cent to civilian flights, while the UAE sees about 50 per cent given over to defence.
If this could be redrawn, the emirates could have a better chance of accommodating the anticipated 1.1 million aircraft movements it will see in 2020 (up from 741,000 in 2012) as it continues to grow as a global aviation hub. Over India, 65 per cent of the skies have been dedicated to military use, but last year an agreement was made – pending safety assessments – to unify it.
FULL BEAM
As well as redesigning airspace, improved navigation technology will enhance airline and air traffic control performance.
The United States’ Next Gen programme is leading the way with a number of procedures and technologies. These include replacing ground-based navigational radar, which date back to the Second World War and only provide updates every 4.7 to 11 seconds, with satellite-based systems that allow pilots and air traffic controllers to know the exact location of planes at all times.
Not only will this allow for more aircraft in the skies, as they are able to fly closer together, but also more direct routings, faster descents, enhanced safety and hundreds of dollars in savings per flight.
A spokesman for the Federal Aviation Administration says: “By 2020, if you want to fly in controlled airspace in the US, you’ll need to have the avionics on board that allow your plane to broadcast its position via satellite. The government funding estimate to the year 2025 is US$15-22 billion. On the airline side, for the avionics, it’s US$14-20 billion.”
Dave Curtis, head of stakeholder and regulatory affairs at NATS, says similar technology is being looked at in Europe: “The current route that an aircraft is required to fly is between two ground-based aids 100 miles part – the plane aims for the second one and flies towards it. Performance based [satellite] navigation is more accurate by a magnitude of about ten. Coming into Heathrow, hopefully you won’t experience any holding, and arrive at a specific time and place.
“If you can streamline the routes, make them more efficient and reduce the workload on the controller, ultimately you can put more aircraft in the system and give the customer more choice.”
BIRDS OF A FEATHER
In the more distant future, Airbus suggests another way of fitting more planes in the sky – flocking together and flying in formation along “express skyways”. Its website reads: “In nature, large birds sometimes fly together to save energy and travel further. When flying in formation, the leading bird’s wings generate whirling masses of air. The following bird benefits from this air current to get some free extra lift, which means it needs to use less energy to fly.
“Aircraft wings create the same effect, which we call ‘trailing vortexes’. Military pilots often use the same formation flying techniques to reduce the amount of energy – fuel burn – that they use.”
OAG’s Grant compares the technology with that being trialled by Google in its self-driving cars. “They’ve got quite a few in San Francisco, but they’re not allowed to take them on the roads publicly. However, it’s estimated that they will improve capacity on the roads by up to 50 per cent because cars will be able to go so much closer to each other.”
There’s no need to feel nervous, though. “Travel will also be safer because you’ll have all these sensors around you and the car will be taking control,” Grant says. “It’s the same with aircraft, which now have traffic collision avoidance systems.”
Sebastien Borel, vice-president of customer affairs for Airbus ProSky, a subsidiary dedicated to improving the performance of global air traffic control, says: “It will take many years to get there but, step by step, we are working on increasing the communication between aircraft and the ground to do closer spacing. It may not be in a V shape, though it looks good, as you would have to look out for wave turbulence. But we are working on technologies to get them closer and closer.”
If this is the case, when you are one day gazing out of the window at the clouds, you might be able to wave to a fellow frequent traveller.
