IndiGo, the country’s largest domestic airline (in terms of market share), signed a memorandum of understanding with the global aircraft manufacturer Airbus for the purchase of 250 Airbus A320neo aircraft on Oct 15, 2014. The order worth $26.55 billion was firmed up by IndiGo in 2015, making it the largest single order ever received by Airbus. The New Engine Option (NEO) jets with the latest generation engines and large Sharklet wing-tip devices promise 15-20% savings on fuel consumption and significant reduction in CO2 emissions.