Civil aviation minister Praful Patel on Monday blamed the heavy fog over the national capital for flight delays and said that the authorities had managed to handle the situation well.
He said that the delays were due to the heavy fog which decreased the visibility below 50 metres, as a result of which even state-of-the-art ILS CAT-III B wasn't effective.
"Flights cannot operate if the visibility is less than 50 metres," Patel told reporters in Mumbai.
On Sunday, the Directorate General of Civil Aviation (DGCA) imposed curbs on aircraft not equipped to land in runway visibility as low as 50 metres.
"No aircraft which is non-compliant with CAT-IIIB will be coming to Delhi during low visibility conditions," Civil Aviation Secretary Naseem Zaidi said in New Delhi.
"We have taken the step that aircraft which are not compliant with the CAT-IIIB will follow a separate fog schedule. These aircraft will be allowed to land only after 10am," he added.
According to a Delhi International Airport Limited (DIAL) official, the technologically superior ILS CAT-IIIB allows compliant aircraft and trained pilots to land even when the runway visibility is just 50 metres.
Despite the new measures on Monday, several flights and trains were disrupted for the second consecutive day as fog enveloped the national capital, leaving a large number of passengers stranded.
The fog, which descended upon the Indira Gandhi International Airport Sunday evening, forced the authorities to enforce the Low Visibility Procedures (LVP), due to which 16 domestic and seven international flights were diverted, while 26 flights were canceled.
"IGI flight operations have been affected by heavy fog. LVP were enforced from 2036 hours yesterday, and terminated at 1036 hours today," a Delhi International Airport Limited (DIAL) official said Monday.
According to the officical, despite heavy fog cover, 257 flights operated under various instrument landing systems that assist in flight operations during poor visibility.
Delhi saw the first heavy fog of this season Saturday, resulting in a massive disruption of flight services. On Sunday too the condition remained the same, with as many as 38 flights being cancelled and 42 diverted. These included both domestic and international flights.
The services resumed by afternoon, while the stranded passengers were exasperated and agitated by the lack of information and cooperation from the authorities.