Aviation Which is India’s largest international airline — IndiGo or Air India? Updated : September 13, 2019 06:46 AM IST CAPA, the airline consulting firm, set the cat among pigeons last week when it said IndiGo overtook Air India by number of seats deployed on international departures. With thin margins and cyclical nature of business, aviation relies a lot on data to understand, sustain and grow routes. Is airline capacity a measure of seats or a measure of ASKs (Available Seat Kilometers)? Let’s find out.