Reducing flight distance not safe, says ATC

The proposal to increase the number of flights handled by Mumbai airport by reducing the distance between airborne aircraft has hit a hurdle.

The proposal to increase the number of flights handled by Mumbai airport by reducing the distance between airborne aircraft has hit a hurdle.

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The city airport's air traffic control (ATC) officials held a meeting last week to discuss the feasibility of the civil aviation ministry's suggestion to reduce the horizontal distance between two aircraft from five nautical miles to three nautical miles. The suggestion to reduce the distance between the aircraft is part of a larger plan to increase the airport's flight handling capacity from 30 movements per hour to 45 movements per hour.

ATC officials pointed out that reducing the distance between two planes could compromise air safety if one of them is heavier. ATC officials said that 'wake turbulence', a circular wind pattern generated by a big plane, could endanger the safety of passengers in the aircraft behind if the latter is smaller and lighter.

"Aircraft of different sizes operate out of the Mumbai airport. Therefore reducing the distance could result in a safety hazard," said a senior ATC requesting anonymity. Worldwide, aircraft are differentiated into four categories depending on their size. While a majority of the planes operating out of the city fall in the 'medium aircraft' category, the airport also witnesses a significant number of wide-bodied planes and turboprops. ATC officials added that currently they maintain a distance of six nautical miles between a big and small plane.

It was suggested that the ATC should put the same type of aircraft in a sequence. "The suggestion is good but it will add tremendous pressure on the controller. Monitoring the type of planes in sequence and simultaneously handling traffic could be difficult," said another ATC official.