Government has no immediate answer to the NIA radar dilemma, as the system in place has been malfunctioning for some time and the recently purchased replacement system is riddled with faults, a source close to the problem revealed.
In an exclusive interview with The Tribune, the source, who wished to remain anonymous, said the repeated breakdown of the current system has forced air traffic controllers to revert to navigating local and international flights without the use of radar – a process that one senior official called “playing chess in the dark”.
The source claimed that the radar failure at the weekend, which stranded 2,000 travellers, is now a normal occurrence at the airport.
According to airport employees, a similar incident happened not even a week earlier.
A new radar system was recently purchased to replace the ailing system for $1 million. However, according to the source, pilots and controllers have not even been trained to use it as yet, as it has already been displaying a number of problems and is still going through a number of tests.
The source claimed that the Ministry of Transport and Aviation is aware of the airport’s radar dilemma, as it has been going on “for quite some time”. The new radar system has its advantages – such as allowing controllers to see weather systems better – however target acquisition is a problem, as controllers have to enter a great deal of data in order to generate a landing target for an aircraft – thus prolonging flight times.
According to an airport official, the present system, which was installed in 1986 has already outlived its life expectancy of 15 years, but was “worth it’s weight in gold” in terms of effectiveness.
With the replacement system so riddled with faults, buying yet another one might be the best option, but this could cost anywhere between $10 million and $25 million, observers say.
According to The Tribune’s source however, something must be done, as the frequent radar blackouts mean that controllers have had to revert to a more complicated method of navigation called a VOR, or VHF Omni-directional Radio Range.
VOR broadcasts a VHF radio signal, encoding both the identity of the station and the angle between it and the target aircraft. This tells the pilot in what direction he lies from the VOR station, referred to as the “radial”.
By comparing two such measurements on a chart, controllers get a “fix” on an aircraft, and can direct it safely to the runway.
Within an hour, an aircraft controller can expect to direct anywhere between 70 to 80 planes. As a result, with only 20 persons on during each shift, these controllers are required to work consecutively for only two hours, as the possibility of misjudging flight paths or speed due to worker fatigue or stress heightens under the circumstances.
Although still quite safe, and within international standards, the VOR system does not allow for flights to be handled as expeditiously as a fully functional radar system would.
As a result, a number of pilots, who prefer not to wait on the VOR system, have either diverted their course, or simply not flown to avoid extended waits on the runway.
“We need to ensure that this sort of thing doesn’t happen again, by making sure that we have a back-up system in place that can reinforce that if this radar system goes out again, we can have a system in place,” the source said, adding that parallel runways are also drastically needed at NIA; as they allow for more free movement and aid increasing the efficiency of landings and take-offs.
“Procedurally, controllers have to restrict the movement of airplanes. You just can’t have one airplane crossing another aircraft’s flight paths – they’re going to hit.
“If you go into Miami centre you could see two airplanes, one landing on the left and one on the right. In and out, all day, no problems. But when you have the flight paths of those airplanes crossing one another, you have to restrict it, otherwise someone is going to get killed.”
NIA handles 190,000 aircraft each year.
By PAUL G TURNQUEST Tribune Staff Reporter
