Pre-departure clearance to aircraft to be upgraded

New Delhi -  Pre-departure clearance to aircraft by Air Traffic Control (ATC) in India is all set for a major technology upgradation as the Airports Authority of India (AAI) at Mumbai  Airport has begun trial operations of data link communication.

The new system will eventually replace the present system of pre-departure clearances being given using voice communication and will eliminate possibility of human error thus enhancing  safety and efficiency of operations, the Ministry of Civil Aviation said in a statement.

The trial operation was launched by Civil Aviation Minister Ajit Singh during his visit to Mumbai June 18.

In addition to Mumbai, such data link departure clearance (DLC) systems are being deployed at Delhi, Kolkata, Chennai, Bangalore and Hyderabad International Airports.

Pre-departure clearance is an authorization issued by Air Traffic Control to the pilot regarding the runway to be used, route to be flown from departure to destination and the cruising level  that the aircraft is expected to maintain.

At present, air traffic controllers, on request from the pilot of an aircraft, issue pre-departure clearance through voice communication using very high frequency radio from tower.

The pilots are expected to read back the entire clearance to confirm correct receipt of the same, again through voice communication.

Such a procedure using voice may lead to potential misunderstanding between the pilot and the controller, the ministry said.

It also results in loss of time for the pilot waiting for his turn to get the clearance as it is not possible for more than one pilot to talk to the controller at a time, it added.

According to the ministry, these limitations can be addressed by using data link communication instead of voice.

In the case of issue of pre-departure clearances using data link, the pilot requests the clearance using the flight management computer in the cockpit. The controller gets the information

about the aircraft requesting the clearance on his work-station.

The controller selects the appropriate clearance from the data base and at the press of a button the information goes to the cockpit of the aircraft via data link.

Getting the information both on screen and print via data link confirms issue and receipt of correct clearance, saves time for the pilot and eliminates human errors thereby enhancing safety

and operational efficiency, the ministry said.