It is basically a problem of cluttering the skies at a particular time that is leading to congestion at the major metro airports.

In Delhi, the problem is most acute between 6 a.m. and 10 a.m. and 9 p.m. to 11 p.m. "There is a virtual stampede for aircraft to land and take-off. It is not uncommon for a plane to circle over the Delhi airport for anything between 20 and 45 minutes. Apart from an increase in the fuel consumed, the longer hours of operations also leads to engines being worked for longer periods leading to greater wear and tear," a senior airline official said.

Airlines estimate that at current ATF prices it costs them Rs 560 per minute in fuel charges alone while they are taxiing on the ground, while it costs Rs 1,950 per minute when the aircraft is holding over an airport.

"Bangalore, Mumbai and Delhi are the worst where taxiing delays are concerned. We have estimated taxiing time of 14-25 minutes in Bangalore, 11-18 minutes in Mumbai and 9-16 minutes in Delhi, while ideally it should be no more than a minute," said an airline official, who added that the airline had reported average delay of eight minutes at Delhi and 5.7 minutes at Mumbai during August-October this year.

Aircraft movements

The Delhi airport handles 525 aircraft movements a day of which more than 260 aircraft movement are reported during the peak hours. "At present, the airport is capable of handling 40 aircraft movement an hour. During the peak hours alone they manage more than 260 aircraft movement which puts pressure on infrastructure," official sources said. During the evening rush hour, the State-owned airline Indian alone has more than 12 arrivals from various metro airports apart from other flights from non-metro and international airports.

To get over such problems, the UK carrier Virgin Atlantic Airways has now started towing aircraft to take-off areas this month at Heathrow airport in London.

The airline's Boeing 747-400 aircraft will be towed to the starting grids near the runway to prevent fuel use while taxiing, thereby not only reducing emissions but also noise pollution and airport congestion.

While airlines here also report some delay in take-off, this is not a major issue with the aircraft not consuming much fuel as the engines are in idle mode, officials said.

The problem can be sorted out through a series of collective initiatives that all stakeholders have to take together, the officials said.