Was the collision a disaster waiting to happen? Gerry Byrne examines the problems with European airspace
The mid-air collision near the Swiss-German border of a DHL cargo Boeing and a Russian passenger Tupelov is almost guaranteed to provoke a major debate about the way European skies are managed.
What some commentators at first gleefully seized upon as an example of Russian ineptitude is now emerging as possibly an accident waiting to happen.
Although the Swiss air traffic controller might appear to have been rather tardy in leaving things to the last moment before issuing his first order to the Russian aircraft just 50 seconds before impact, and the Russian commander appears to have responded with even less alacrity, the seeds of this collision were probably sown in a different airspace.
Because of its geographical position, the skies above Switzerland are a sort of celestial crossroads and several major air routes cross the country (for practical reasons, its controllers also handle a chunk of airspace which extends into Germany). The Russian aircraft, on a south-westerly heading towards Spain, would have been assigned its altitude and course while it was still in German airspace. The DHL cargo plane, on a north-westerly trajectory from the Gulf to Belgium, most likely was assigned its altitude and course, or had its existing course confirmed while flying in Italian, or possibly Austrian airspace. As each aircraft neared airspace controlled by Swiss air traffic it was "handed over" and instructed to contact its new controller on a new radio frequency.
Three, possibly four separate air traffic organisations would have played a role in directing the movements of these aircraft in the few minutes before the accident. Investigators will want to know if the aircraft were properly handed over at air traffic control level. In other words, how much advance notice did the Swiss have from other air traffic centres that two aircraft were converging on each other at the same flight level and was it was sufficient for the hapless controller on duty to take action to separate them?
Equally, they will want to know if there was a mechanism whereby the German controller could have learned that the course he approved for the Russian was targeting for doom. And why, when the Swiss controller was getting a poor response from the Russian pilot, did he not order the DHL aircraft to alter course as well, perhaps by ordering it to climb. In the event, the Russian did belatedly start to descend but by that time the DHL Boeing, in a manoeuvre possibly triggered by its anti-collision avoidance system (ACAS), was also descending to a fatal rendezvous.
Modern air traffic control was born out of the mid-air collision of two aircraft over the Grand Canyon in 1956, and its sole purpose is to prevent a repeat of that disaster. As Monday night's accident demonstrated, it has not been entirely successful but, its adherents say, the alternative is a far bleaker scenario. Controllers work, not by barking commands like the Swiss did at the Russian on Monday, but by shepherding aircraft at intervals along a series of virtual tubes in the sky, each a thousand feet high and five miles wide and monitoring their progress by radar. The pilot has little or no control over his safety from collision and his navigation is effectively handled for him from the ground. No two aircraft at the same altitude are allowed any closer than five miles to each other, or within one thousand feet in the vertical sense. A controller has failed in his task if they approach any closer, even if there is no danger of collision. Because early altimeters were not as accurate at higher altitudes, that vertical separation was once 2,000 feet above 29,000 feet.
Unfortunately, for an aircraft flying over Europe, it is far from an orderly procession through the sky. The pilot has to re-confirm his flight plan as he passes through a virtual jig-saw of sovereign airspaces and the nature of the airways means he cannot fly direct to his destination but, more often than not, has to follow a series of dog legs between navigation beacons to reach his destination. Although each air traffic control centre works to the same international operational hymn sheet, that is no guarantee that they operate the same equipment, or that their computers can always communicate coherently. It remains to be seen if any lack of communication contributed to Monday's collision.
Eurocontrol, the umbrella body for European air traffic control would like to abolish these artificial boundaries and place all European airspace, from the Atlantic to the Urals under a unified management. The potential benefits are enormous: advances in safety equipment and new operational techniques could advance in lockstep, routes could be better planned and flights smoothly executed from start to finish. Better still, new airspace could be opened up to reduce congestion: according to most aviation doomsayers mammoth delays can be expected in Europe's skies after 2010 when growth in traffic will have overtaken growth in air traffic facilities.
But it is easier said than done. Despite being advocated since 1959, Eurocontrol only recently succeeded, after Byzantine negotiations, in persuading European air traffic control centres to agree to reduce vertical separation above 29,000 feet to 1,000 feet, thus opening up more airspace and reducing congestion. Other techniques it is pioneering, like Datalink, effectively emails between controllers and pilots - which should avoid misinterpretation of verbal radio instructions - have long been a technical possibility but have only been introduced in a few centres. Other new techniques, like ADS-B, which shares a fuller air traffic picture with pilots, are also many years away.
Further techniques, which restore more autonomy to the cockpit and make badly needed use of airspace outside of the airways, are even further away. In the US the Federal Aviation Administration is officially committed to introducing Free Flight, a technique which largely abolishes the airways and allows pilots more influence over the routes they fly while giving on-board technology a greater role in the avoidance of collisions.
Free flight also means less congestion and few air traffic delays, its adherents say. Eurocontrol has conducted trials in the system which, it says, has some merits. But, until European airspace is better co-ordinated, say Eurocontrol insiders, Free flight, or any other technique to free up congested airspace, is just so much pie in the sky.
Gerry Byrne is a journalist specialising in aviation