New Delhi, Dec 29 : The Directorate General of Civil Aviation (DGCA) has launched an investigation into recent delays and diversions at Delhi Airport as the capital city grapples with thick fog affecting airline operations. The inquiry aims to determine the causes behind these disruptions, said the sources. Amidst the foggy conditions, airlines are under scrutiny to ascertain whether they deployed appropriately equipped planes and adequately trained crews for low-visibility situations. 'Data is being verified from airlines and air traffic control (ATC) to check if the flights were diverted due to captains not being trained for low-visibility operations,' said the sources. Delhi Airport currently has only one CAT III-equipped runway designed for operations in low visibility. The second runway, 28/10, is undergoing re-carpeting, affecting its usability. Once the re-carpeting process is completed, the DGCA will inspect the runway for recertification as a CAT III B-compliant runway. Between December 25, 12 a.m, and December 28, 6 a.m, a total of 58 flights, predominantly operated by domestic carriers, experienced diversions due to low visibility, as per airport sources. The majority of these flights faced cancellations as pilots lacked the necessary training to operate in challenging low-visibility conditions. Specifically, IndiGo witnessed 13 diversions, Air India 10, SpiceJet 10, Vistara 5, Akasa Air 3, and Alliance Air 2 at Delhi Airport during this period. "As per the regulator, the fog period is defined from 10th Dec to 10th Feb. The FOG window for CAT3 operations is defined from 9 pm to 10 am. On Wednesday, weather dropped below minima after 1930 leading to diversions. Out of 10 diversion from 25th to 28th, one was a ferry flight and one (SG 204 BLR -Del) was having Cat 3 pilots," said the SpiceJet spokesperson The India Meteorological Department (IMD) said that dense to very dense fog at many parts is likely to continue over Northwest India during next two days and gradually improve thereafter. 'Dense to very dense fog conditions are very likely to continue during night/morning hours in many parts of Punjab, Haryana, Chandigarh, Delhi and some parts of Uttar Pradesh till Saturday (December 30) morning and in some parts for subsequent three days,' said the IMD. /IANS