Poor procedures and heavy workloads on air traffic controllers were blamed yesterday for a near-miss incident near Heathrow when two aircraft flew within 200 feet of each other and were a split second away from a major catastrophe.
A potential disaster loomed in August last year when a Virgin Express Boeing 737 was attempting to land as a British Airways Boeing 737 was taking off. The catastrophe was prevented only when a training inspector supervising the departures controller overheard the arrivals controller announce that he had turned the Virgin flight into the path of the BA 737.
Both aircraft were then instructed by the two controllers to alter their course. They were only 200 feet vertically apart when the higher aircraft was at 2,400 feet, according to the official report from the Air Accidents Investigation Branch.
As a result of the incident, Heathrow - which has about 600 landings per day - has changed procedures for planes that miss initial approaches to minimise conflict with departures and reduce the need for controllers to intervene.
The incident happened on a cloudy day in August 1997 shortly after a Sabena aircraft carrying passengers for Virgin initiated a missed approach or a "go-around" procedure carried out when a pilot or a controller is not satisfied with the aircraft's approach.
Both the air departures controller and the training supervisor failed to tell the arrivals controller that the BA aircraft was airborne, while the BA aircraft did not get agreement from air departures before advising the Virgin Express of which path to take. Mr Bill Billing of the Guild of Air Traffic Controllers said: "Our people are under a lot of pressure, as are all controllers, due to the inexorable increase in air traffic movements. This was a genuine mistake. It was not someone trying to be smart. It was human error."
"It was a very serious incident. There's no question about that," Mr Keith Williams of National Air Traffic Services, which runs Britain's air traffic control service, told BBC radio. "It happened basically because of human error. I think in all walks of life we recognise that human error occurs," he said.
"We have learned the lessons from this bad error, and Heathrow is that much safer as a result, Mr Williams said.
Mr Williams denied that the skies were getting more dangerous, saying that there were between 7 and 8 per cent more aircraft in the sky over Britain this year, but also more controllers and more sophisticated control systems. "Compared with any other country in the world I'm sure we have the safest service."
In Washington, the Federal Aviation Administration has urged airlines to replace insulation on most of the world's 12,000 passenger aircraft because it can catch fire, the Washington Post said yesterday.
The recommendations stem from the investigation of the September 2nd crash off eastern Canada of a Swissair plane that killed all 229 people on board. Investigators found that minutes before the crash, the pilots reported smoke in the cockpit. They also found insulation of the type that was involved in at least four nonfatal aircraft fires between 1993 and 1995. The insulation, located under the skin of the plane, could catch fire when exposed to extreme heat, the FAA said.