Are Britain's skies really running out of room for planes?

As UK's air-traffic controllers handle their highest-ever number of aircraft movements, they say congestion will build unless changes are made

Contrails or vapour trails made by passing aircraft in the sky above the Houses of Parliament (AFP/Getty)

Are the skies really running out of room?

According to NATS, Britain’s air-navigation provider, they are. “Air traffic chiefs are warning that the skies are now nearing full capacity,” the firm said as it prepared to handle its highest-ever number of flights in a single day: 8,800.

Jamie Hutchison, Director at NATS’ Swanwick air-traffic control centre, said: “In the last few weeks we have already safely managed record-breaking daily traffic levels, but the ageing design of UK airspace means we will soon reach the limits of what can be managed without delays rising significantly.”

The firm is calling for a radical overhaul of the network of flight paths, which were devised decades ago when navigation technology was much more rudimentary — and aircraft were noisier.

NATS quotes a Department for Transport survey which found: “If the airspace remains unchanged, by 2030 there will be 3,100 days’ worth of flight delays – 50 times the amount seen in 2015, along with 8,000 flight cancellations a year.”

More efficient use of airspace would also have environmental benefits, slightly reducing the damage caused by aviation.

So why doesn’t the Government simply give a green light to what NATS wants?

Re-drawing the map of the skies would mean that some locations which currently experience a large number of planes at lower altitudes would get some relief — but other parts of the country would see a sharp increase in the amount of air-traffic movements that many people see as intrusive.

As the endless controversy over expanding Heathrow has shown, aircraft noise is an extremely sensitive political topic.

Chart shows the increasing number of flights per month over the last five years

Are there other solutions?

The extreme concentration of air traffic in the London area, which is the busiest sky in the world, could be reduced by taxation: applying a higher rate of Air Passenger Duty for flights from the capital’s airports.

This would have two marginal effects: persuading some people to use other forms of transport, particularly for domestic trips and services to Paris, Brussels and Amsterdam; and diverting some travellers to airports outside South East England, where the stress on the air-traffic system is not so pronounced.

But such a move would also politically very unpopular and it is most unlikely to happen.

Slicing the skies over Britain more thinly is another possibility. More capacity can be extracted from the skies by reducing separation between aircraft, though this naturally raises concerns on safety. In 2002, vertical separation between aircraft in Europe was reduced from 2,000 feet to 1,000 feet, which vastly increased capacity.

Is this the most pressing air capacity issue?

No. London remains the world capital of aviation despite a continuing failure to expand airport capacity. With the runways at Heathrow and Gatwick being the busiest in the world, there is very little slack in the system. On a normal day, this is evident in the queues of aircraft waiting inefficiently to take off and land; and when something goes wrong, such as the Air Canada aircraft that burst a tyre on take off at Gatwick this week, the lack of resilience triggers widespread disruption.

But the performance of this Government, as well as previous administrations, suggests that short-term local political expediency outweighs long-term infrastructure needs.