Delhi's Indira Gandhi International Airport has been hit by numerous cancellations and delays over the weekend caused by poor morning weather conditions.
Heavy fog has disrupted flights over the past week, with visibility dropping as low as 100m and many private airlines have seen their schedules decimated.
Most aircraft require a minimum of 800m of visibility to make a safe landing.
The airport has recently installed an advanced CAT3b landing system that allows planes to land even when visibility is only 50m, but the system is expensive and not all of India’s private airlines have installed the system onboard their aircraft. Air India, Kingfisher, Indigo and some Jet planes have the Cat 3b system and pilots trained to use it, other carriers have been forced to ground their aircraft for large parts of the day, wreaking havoc with schedules. In 2007, Indira Gandhi International Airport handled 23 million passengers annually and a planned expansion programme will increase its capacity to handle 100 million passengers by 2030.