An air-traffic controller reported an incident on Wednesday in which a Boeing 737 and a Boeing 757 were involved in an air-miss two miles west of Heathrow. The other case being looked into is an air-miss on 3 July involving a Heathrow-bound Boeing 747 and a Luton-bound Gulfstream executive jet over Lambourne, Essex.
In the Wednesday incident, the two aircraft are thought to have come within 200ft of each other while the aircraft last month are believed to have been within 300ft at one time.
However, the Civil Aviation Authority, the body which regulates air safety, said that the number of incidents that were "risk-bearing" was decreasing every year. The CAA said that there were six in 1996, whereas there had been eight in 1995 and 14 in 1994.
These events, experts said, would not have happened in the United States. There, aircraft are fitted with traffic collision avoidance systems (TCAS) which warn pilots of approaching aircraft. The CAA has given British airlines until 2000 to install similar devices in their aircraft. The Consumers' Association called on the CAA to "shorten the timetable".
The Wednesday case is now being studied by the joint air-proximity assessment panel, while the July incident is the subject of an investigation by the joint working group on air proximity. Under safety regulations, any air- traffic controller involved in an "airprox" incident must leave his duties and complete a report.
It was the working group's report earlier this week that revealed an extremely serious incident last November when two British Airways Boeing 757s were seconds from colliding over Kent as they waited to land at Heathrow. One of the pilots, who took last-minute evasive action, said the aircraft would have collided had the weather been poor. One of the pilots involved called on the authorities to speed up installation of TCAS devices. He told the investigators that the "equipment had been shown to be highly effective in preventing close encounters in a number of scenarios".
The report called for a review of air-traffic control procedures, particularly when aircraft were bunched up waiting to land.Reuse content