After remaining disrupted for the past two days due to dense fog, air operations at the IGI airport in New Delhi were normal on Thursday.<br/><br/>An airport official said though there was shallow fog, the runway visibility was around 1,000 metres which was good enough for normal flight operations.<br/><br/>AIR correspondent reports all domestic and international flights were operating as per<br/><br/>schedule. Director in charge of Airport Met Department, Mr R K Jenamani said heavy fog has played havoc with flight operations this season.<br/><br/>He said this year IGI airport has witnessed a total of 172 hours of dense fog.<br/><br/>In the past ten days, about 190 flights have been cancelled while around 1,200 have been delayed.