What Does ‘On-Time’ Actually Mean?
The most important question is also the most basic. In India, the Directorate General of Civil Aviation (DGCA) traditionally defines a flight as 'on-time' if it departs from the gate within 15 minutes of its scheduled time. This is known as departure-based
OTP. However, many global analytics firms, like Cirium, and passengers themselves care more about when the flight arrives. A flight can push back from the gate on schedule, meeting the DGCA's metric, but then wait on the tarmac for 40 minutes before takeoff and ultimately land late. This discrepancy is key: an airline might look good on official departure stats while its passengers still experience significant arrival delays.
Whose Data Are You Looking At?
Not all data is created equal. The monthly reports from the DGCA focus on domestic airlines at a select number of major Indian airports. For instance, the latest available DGCA data for May 2026 showed IndiGo as the most punctual airline, followed by Akasa Air and then the Air India Group. However, a more recent June 2026 report from the global firm Cirium, which measures on-time arrivals, ranked Air India as the fourth most punctual airline in the world. This shows how different methodologies and data sets can paint vastly different pictures. A global ranking might reflect strong international operations, while DGCA data gives a more specific view of domestic performance at key metros.
Are They Punctual or Just Padded?
Airlines have a clever trick up their sleeve to boost their on-time numbers: schedule padding. This is the practice of intentionally inflating the published flight duration. A flight that only takes 1 hour and 40 minutes in the air might be scheduled as a 2-hour and 30-minute journey. This extra 50 minutes creates a buffer to absorb potential delays from taxiing, air traffic congestion, or slow turnarounds. The flight can be technically late by 30 minutes but still arrive 'on-time' according to its padded schedule. So, when you see an airline consistently boasting high OTP, it is worth checking if their flight durations for a given route are significantly longer than competitors'.
What About Cancelled Flights?
An impressive on-time record can sometimes hide an airline’s tendency to cancel its most problematic flights. If a flight is consistently and severely delayed, an airline might choose to cancel it altogether rather than let it damage its punctuality score, as cancelled flights are often not counted in OTP calculations. To get a fuller picture, look for a metric called the 'completion factor'. A high completion factor, like the 99.7% Air India reported for June 2026, means the airline operated nearly all of its scheduled flights. A good OTP combined with a high completion factor is the true sign of a reliable airline.
Is It the Airline or the Airport?
Sometimes, the airline isn't entirely to blame. The airport itself plays a huge role in punctuality. According to DGCA data from May 2026, Chennai International Airport had the best on-time performance in the country, with 92.2% of its flights departing on schedule. In stark contrast, Mumbai's airport had the lowest score among the top ten, at just 70.5%. An airline flying out of a congested, capacity-strained airport like Mumbai will struggle to maintain punctuality, no matter how efficient its own operations are. These airport-specific issues, from a lack of parking bays to runway traffic, can cause cascading, or 'reactionary', delays across the entire network.
