Barely a month before the Garuda and Air Lanka aircraft incident, two Alliance Air and Jet Air flights escaped certain destruction. According to sources, this near miss happened near Coimbatore, which also falls within the Thiruvananthapuram Air Traffic Controller air space.Alliance Air, on its way from Kochi, was cruising along when the pilot was alerted by a signal from the traffic collision avoidance system (TCAS) in the aircraft. Directly on its flight path was a Jet Air flight on the Chennai-Kochi sector. The TCAS in the Jet Airways flight also worked in time and the pilot changed course to avert a major disaster.

This incident happened on January 27, at around 1 pm. The ATC wouldhave seen both aircraft rapidly approaching each other on the screen before him. In this case, however, the senior aerodrome officer on duty informed his seniors, unlike the official who was involved in the Garuda-Air Lanka aircraft near-miss. The Director General of Civil Aviation (DGCA) has ordered an inquiry - which is currently on - based on a complaint filed by Jet Airways.

The senior airworthiness officer in the airworthiness wing under DGCA has been asked to probe the incident. Sources say that the video tape, which would have been clinching evidence, is yet to be replayed. However, the communication between the aircraft and the Air Traffic Controller, which is recorded by the communications wing, has been replayed for the inquiry officer.

As for the Garuda-Air Lanka incident, no inquiry has been ordered as yet. However, the senior aerodrome officer who was on duty at the time has been removed from area control duty and is to be placed either at the tower, briefing unit or the coordination wingtill the inquiry is complete. Sources say, she will also be charged with suppression of facts.

One reason for the present state of affairs could be that the National Airports Division at the airport is sharply divided, with no love lost between the communications wing and the aerodrome wing. Charges fly fast and thick.

Said one communications wing official: "It was pure dereliction of duty by Air Traffic Controller staff which caused the near-miss involving Garuda and Air Lanka aircraft. If there haven't been any major air mishaps in the recent past, it is solely because of the TCAS. There is absolutely no chance of equipment failure. Thiruvananthapuram airport has the most modern equipment among the major airports. The VCCS helps the Air Traffic Controller staff to select the desired frequency. We have the radar, VOR (Very High Frequency Omni Range) and the Instrument Landing System."

The Air Traffic Controller staff dismiss charges of inefficiency and point out the high stress level under whichthey work and hurl their own set of accusations against the communications wing. "The distance measuring equipment at the airport, which helps us measure the distance of the aircraft in flight, has been unserviceable for the last three months," claim ATC staff.

"High Frequency Radio Telephone, which is the only means of communication now over the high seas, is undependable. Air safety depends on the position reports Air Traffic Controllers get from each compulsory reporting point in the flight path. There is no pilot-controller communication and we have to depend on the HFRT operators to get the position reports. This has been identified as a major problem for air safety," they add.

Sources said terrestrial navigation and communication aids will be phased out by 2005 and replaced by the Future Air Navigation System which will depend on the global navigation satellite system.