Thursday, December 09, 2021

Kolkata: Fog-day flights hit by visibility device snag, airlines fear more disruptions

Kolkata: The city airport experienced fog-related flight disruptions on Wednesday morning, when there should not have been any. Airport sources said a critical instrument that measured the visibility in the middle of the runway had developed a snag. That, in turn, led to downgrading of the category of instrument landing system at the airport from CAT III-B, which allows flights to operate even in extremely low visibility, to CAT I that needs considerably higher visibility for operations.With no clarity on when the middle runway visual range (mid-RVR) would be operational again, airlines are worried about more disruptions in the next couple of months. For flyers, this could mean huge delays and crowding in the terminal during the busy winter holiday season.

"The airport meteorology department is the custodian of the RVR equipment. It became unserviceable last month and we had immediately asked them to repair it. We had a lengthy meeting with the Met director who said he had informed his seniors in Delhi about the matter and was trying his best to repair or replace the equipment at the earliest. But until it is repaired, we may face problems in the coming weeks as well," said a senior airport official.


The ILS Category III-B landing system installed at Kolkata airport allows aircraft to land till visibility is up to 50metre on the runway. If it drops further, operations have to be suspended. But on Wednesday morning, landing had to be suspended when the visibility dropped below 550m, while take off was suspended below 200m due to the absence of the mid-RVR. The worst the visibility had dipped to was 150 m, higher than the minimum required for flights to land if the mid-RVR was functional. While Boeing aircraft can land at a minimum visibility of 50m, an Airbus aircraft requires 75m visibility to land. For take-off, the minimum RVR requirement is 125m.

Kolkata airport has a touchdown-RVR, mid-RVR and end-RVR. But with the mid-RVR not working, a low-visibility procedure was initiated in which minimum visibility required for take-off is 200m and for landing 550m.

Consequently, an Ethiopian Airlines flight from Addis Ababa to Dhaka, which was diverted to Kolkata due to poor visibility over the Bangladesh capital, had to be re-diverted to Mandalay in Myanmar at 6.15am. Five minutes earlier, an IndiGo Airlines flight from Bengaluru was diverted to Bhubaneswar. At 7.30am, a SpiceJet cargo flight from China's Wuhan was diverted to Dhaka, where the weather had cleared by then. Another IndiGo flight from Chennai was diverted to Bhubaneswar at 8.05am. In between, an IndiGo flight, which was to take off, had returned to the bay for visibility to improve. Several other morning departures operated as usual when RVR requirements for them were met.

When the suspension was announced passengers of some flights had already completed boarding and kept waiting till the situation improved. Another lot were made to wait at the terminal and they boarded the aircraft after the suspension was lifted but had to wait further till the flights scheduled to take off before them took off. Frustrated passengers took to Twitter. "IndiGo flight 6E 375 scheduled departure at 7am. Boarded passengers at 10.45am. Pilots were not available. Pilots arrived at 11.22am. Still waiting for departure. Miserable conditions for passengers arriving at the airport at 5.30am," wrote a Raipur-bound passenger, Pawan Kajaria, at 11.32am. Air travel time between Kolkata and Raipur is hardly one-and-a-half hours.

09/12/21 Subhro Niyogi & Tamaghna Benerjee/Times of India

To Read the News in full at Source, Click the Headline


Post a Comment