Busy skies pile pressure on controllers

Air traffic controllers across Europe are under intense pressure as they struggle to maintain safety in the world's most crowded skies.

As holiday flights begin to build to the mid-summer peak, air traffic control services are in disarray in several countries due to financial problems, political interference and industrial unrest.

More than 5,000 aircraft jostle for space above Britain every day. Disaster almost struck last month, when two British Airways jets carrying more than 300 passengers and crew came within 200ft of each other over the Channel. An attempt to warn the pilots failed when a piece of equipment at the new £623million air traffic control centre at Swanwick, Hampshire, did not work.

Despite a high number of near misses, commercial passenger aircraft are rarely involved in midair collisions. Most such accidents involve light aircraft and occur near airports during landing and take-off. In the US, no mid-air collision involving a passenger airliner has taken place for more than a decade, and nearly all such accidents occur within three miles of an airport. Aviation experts say a collision between two aircraft at normal altitude and in good weather is particularly unusual.

This is the period when pilots have most time to watch for other aircraft - and visual alertness is still said to be the best guard against calamity. But, this is also the longest, and potentially most boring, phase when risk of pilot complacency is greater.

Accident investigators say a common thread in almost all mid-air collisions is inattention by flight crews. The presence of two pilots in the cockpit can militate against safety because each relies on the other to watch for aircraft.