The new systems will enable air traffic controllers (ATCs) to warn pilots if an aircraft comes in close proximity to the ground, reducing the chances of an air crash.

"We want that all airports where the secondary radar system has been installed, should also be equipped with the minimum safe altitude warning or MSAW system. This will help in increasing safety", said director general of civil aviation HS Khola.

The airports which are equipped with a secondary radar system include Delhi, Chennai, Calcutta, Guwahati, Thiruvananthapuram, Ahmedabad and Hyderabad.

The secondary radar system at Mumbai airport is expected to become operational in another two months.

The MSAW system will also be installed at airports which are targeted to be equipped with the secondary radar system this year, which include Nagpur, Bhubaneshwar and Mangalore.

Meanwhile, to prevent chaos from reigning at the Delhi airport in winter months, the DGCA plans to counter the fog factor by installing the Category III landing system. The Cat III landing system allows pilots to land their aircraft in low or even zero visibility.

"The Category III landing system consists of two aspects, runway or ground installation and training of pilots. Both the jobs have started, the pilots are being trained by the various airlines", said Khola.

Though the Airports Authority of India has already awarded the contract of strengthening the runway to a foreign company, it is unlikely that the work will be completed in time for the foggy months of December and January. Last winter, a thick fog over Delhi had thrown flight schedules out of gear, leaving hundreds of passengers stranded.

Safety in Indian skies has been a main area of concern ever since the mid-air collision of two aircraft over Charki Dadri in 1996. The DGCA has since separated air corridors in north-west India for arriving and departing aircraft. It has also made it mandatory for all aircraft to be equipped with the air-borne collision avoidance systems (ACAS), which alert pilots of aircraft flying close by.

The major airports in India have also upgraded from the primary radar system, which called for manual calculations of aircraft height by the ATCs thereby making them prone to human error, to the secondary radar system, where computerised aircraft height calculations are available.