The Air Traffic Control (ATC) at the Delhi airport witnessed a minor scare on Monday after a technical snag in the radar system. It meant that data of the aircraft arriving or departing from the airport were not available to them.
Though safety of the passengers was not compromised, the snag led to congestion and delays throughout the day.The incident occurred at 11.45am on Monday when Flight Data Processing System (FDPS) at the ATC collapsed suddenly.
The input that is received from the radar are actually signals and this raw data is processed and converted by the FDPS, which provides data and coordinates of each flight such as its speed, height and flight code among others, said a senior ATC official.
The Delhi ATC manages nearly 1,000 flights at the airport every day day, apart from all the traffic in the Delhi air space — an area that stretches from Pakistan and Afghanistan border to Nepal border and from Srinagar to Varanasi.
The snag occurred in the air traffic management software AutoTrac-III, which was introduced in 2010 and had collapsed four times that year itself. On Monday, the older software system AutoTrac-II, which serves as the backup, was put into use. The main system took about an hour to resume work, sources at the airport said.
To ensure aircraft don’t get too close to each other, the minimum separation was increased and planes following each other were told to fly at different altitudes. This led to huge delays at the airport that continued till evening with flights getting delayed by more than an hour.
“Though the position of the aircraft were available from the radar, we had to manually correlate the flight details with their position,” said a ATC official, adding, “It is like you are observing a cricket match at a stadium and none of the players are wearing their T-shirts with their name and number on it,” he said.
Sources said that the problem occurred during testing of the AutoTrac-III, when ATC officials shifted it from normal mode to safety mode for a check.
Despite more than six such incidents since it was introduced, including some instances when the ATC screens went blank, the Airports Authority of India (AAI) — that manages all civil air traffic — tried to downplay the incident.
“We have multiple layers of safety and the moment the FDPS went down, the backup system took over,” said an AAI spokesman. “Operations continued on our redundant FDPS and there were no concerns of safety. Our systems are geared up to do such switch over arrangements as per safety requirement,” he said.