No-frills carrier IndiGo retained its leadership in the domestic market during May, a month that saw a 9% increase in the number of passengers carried over the previous month with more people opting for air travel during summer holidays.

IndiGo clocked 38.9% market share, carrying 27.69 lakh passengers during the month. The Gurgaon-headquartered carrier maintained its lead over Jet Airways (18.3%), Air India (15.8%), SpiceJet (11.7%), GoAir (8.6%), JetLite (3.2%), AirAsia India (1.3%), Vistara (1.3%), Air Costa (0.9%) and Air Pegasus (0.1%).

In terms of passengers, Jet Airways clocked the second-highest number at 13.01 lakh, followed by Air India (11.28 lakh), SpiceJet (8.37 lakh), GoAir (6.13 lakh), JetLite (2.25 lakh), AirAsia India (0.94 lakh), Vistara (0.93 lakh), Air Costa (0.61 lakh) and Air Pegasus (0.06 lakh).

The number of passengers carried by domestic airlines during January-May 2015 rose 21% over the previous year to 3.2 crore, DGCA said. This, despite the second-largest no-frills carrier, SpiceJet, reducing its fleet considerably during the period.

In May, SpiceJet registered the highest load factor of 93.1%, primarily due to various discounts rolled out by the airline earlier in the year. IndiGo was a close second with 91.9%, followed by GoAir (89.4%), Air Asia India (81.4%), Air Costa (81.2%), Jet Airways (81.1%), Air India (80.4%), JetLite (79.4%), Air Pegasus (78%) and Vistara (71%).

May’s passenger load factor rose over the previous month primarily due to the onset of tourist season, DGCA said in a statement.

All scheduled commercial airlines, except Jet Airways and JetLite, clocked a higher load factor in May than in April. The month also saw Bengaluru-based Air Pegasus start its operations.

Though the JetAirways management adopted a single-brand strategy late last year, the airline continues to report performance figures for its former low-cost subsidiary, JetLite, since the fleet that serviced the no- frill carrier still runs on the JetLite/JetKonnect air operating permit (AOP).

Despite the lowest load factor, full-service carrier Vistara registered the best on-time performance (OTP) of 98.5% at the four metro airports of New Delhi, Mumbai, Hyderabad and Bangalore. Others in the list included Air Pegasus (93.5%), AirAsia India (86.7%), Jet Airways (83.6%), IndiGo (80.2%), Air Costa (79.9%), Go Air (77.9%), Air India (77.7%) and SpiceJet (72.1%).

During the month, a total of 858 passenger complaints were received by airlines. SpiceJet registered the highest number of complaints at 2.2 per 10,000 passengers, followed by Air India (1.5), AirAsia India (1.4), Jet Airways (1.4), GoAir (1.1), AirCosta (0.7), IndiGo (0.7), Vistara (0.2).