New Delhi: Delhi International Airport Limited (DIAL) has written to the Union Ministry of Civil Aviation with reasons behind the delay in re-carpeting the second runway at the facility after the ministry pulled up DIAL over the issue, following fog-related delays that hit flight operations the past week.According to the Indian Express, DIAL explained that a compressed timeline post-G20 Summit in September and pollution-related curbs imposed by the Delhi government posed challenges to completing the project within the stipulated time.The implementation of GRAP IV norms, due to pollution concerns, disrupted the supply chain for civil works, the airport operator said. GRAP IV restrictions, which came into effect on November 5 last year, banned the entry of polluting vehicles from other states in Delhi in addition to other curbs to combat the poor air quality in the national capital.DIAL also highlighted delays in the supply of runway lights citing supply chain complexities and unexpected challenges during the cable-laying process, including duct blockages. Despite these challenges, DIAL has assured the ministry that it will meet the January 19 deadline for the project’s completion.The ongoing re-carpeting work pertains to the Indira Gandhi International Airport’s (IGIA) second runway, known as 28/10. Once completed, the airport authority will initiate steps to make the runway CAT III compliant.CAT III compliance allows for landing in very low visibility conditions, such as fog, rain, or snow. Currently, the Delhi airport has one CAT III compliant runway, 29L/11R, closer to the “city side” or Gurgaon. The newest runway, 11L/29R, is only partially CAT III compliant and is awaiting certification.After the re-carpeting is finished, the Directorate General of Civil Aviation (DGCA) will conduct an inspection to identify any necessary changes. According to the report, one DGCA inspection has already been carried out on January 15.Hundreds of flights have been disrupted over the past few days because of fog in north India. In new rules to tackle the airport chaos, the aviation ministry has asked airlines to cancel flights delayed beyond three hours, NDTV reported.