New Delhi, Dec. 15 -- Just as IndiGo's recent flight disruption crisis appears to be easing, fresh cancellations and delays hit passengers on Monday as a thick blanket of smog enveloped Delhi and nearby regions.

Poor visibility disrupted flight operations at Delhi airport, with air quality in the national capital and adjoining areas remaining in the "severe" category. With flight disruptions happening more often, many passengers remain unsure about their rights.

Here's how you can protect yourself from unexpected situations and get your money back in case your air travel plans are disrupted by sudden cancellations and delays.

Based on the circumstances, passengers are entitled to three distinct remedies in cases of airline-caused disru...