Tension in cockpit on way to Bangalore
13 Jun 2008, 0229 hrs IST, V Ayyappan,TNN
CHENNAI: Fifteen minutes after take-off from Kamaraj domestic airport and just easing into a cruising altitude at 25,000 feet, the pilot of a Chennai-Bangalore aircraft peers at the panel of his navigational aid, tuned into the 112.3 mhz VOR (Very High Frequency Omni Range) signal from Bangalore. To his surprise and shock, he finds he is just 20 nautical miles from the Bangalore international airport. Frantic checks reveal that he is still 90 nautical miles from Bangalore airport but the equipment is picking up another signal of the same frequency — from the naval air station at Arakkonam.
This is a typical scenario encountered by pilots flying the Chennai-Bangalore or Tirupati-Bangalore route ever since the airport opened at Devanahalli, near Bangalore.
When the new airport was set up, the communications division of the Airports Authority of India (AAI) selected the same frequency used by the naval air station at Arakkonam, a first in aviation history anywhere in the world.
Hence, aircraft often mistake Arakkonam for Bangalore and vice versa. While flying the 150-nautical-mile distance from Chennai to Bangalore, aircraft track the wrong VOR for seven to eight minutes while covering a distance of 30 to 40 nautical miles at cruising altitude. AAI officials have acknowledged the problem and said they would “sort it out.”
This becomes a safety hazard when the radar fails and air traffic controllers are forced to depend on the position relayed by pilots. “When the radar fails at Chennai, air traffic controllers ask for the position of the aircraft to plot the flight path. There is the risk of the pilot reading out the wrong information displayed in front of him. This could be catastrophic,” said a pilot flying in the sector.
Though there have been no near-misses so far, “this is a high risk scenario because the Chennai radar fails sometimes. If we get wrong information about the status of an aircraft, there is a possibility of flight paths crossing,” said an air traffic controller. AAI failed to check whether any other airport was using the frequency before they assigned it for Bangalore.