Fog is turning out to be a worrisome factor for morning flights to North Bengal since an Indigo flight from Kolkata on Thursday initially failed to make a landing at the Bagdogra airport due to low visibility and returned to the city for a later take-off.
An Indigo flight 6E6359 took off from the Kolkata airport at 9:30 am and was scheduled to land at Bagdogra at 10:45 am. However, the flight failed to make a landing at the airport and instead chose to hover in the air for a bit, hoping that visibility would increase, allowing the flight to head for the runway. With no luck, it returned to Kolkata and took off later, finally landing in Bagdogra at 2:35 pm tentatively.
Morning flights to this North Bengal airport were out of the question even a few years back till the airport was upgraded with CAT-II Instrument Landing System (ILS) that aided flights to land with low visibility. The commissioning of the CAT-II ILS had finally allowed morning flights to reach this hill station.
However, a Bagdogra airport official said at present the ILS is not fully operational due to runway resurfacing work. “The glide path mechanism of the ILS is not functional due to the runway resurfacing work taking place at one end of the runway. However, no flights were cancelled or diverted since the work is mostly taking place at night when the passenger flight operations have stopped. At present, there is enough visibility of about 2400 meters.”
There are two main components of an ILS system -the glide scope and the localizer. The glide scope component of ILS provides vertical guidance to the pilot during the approach and is generally located 750 to 1,250 ft down the runway from the threshold.
The localiser provides lateral guidance and is situated on the centreline at the opposite end of the runway from the approach threshold.