India's largest low-cost carrier, IndiGo, has signed a Memorandum of Understanding for 180 eco-efficient Airbus A320 aircraft of which 150 will be A320neo's and 30 will be A320s. It is the largest single firm order number for large jets in commercial aviation history, and also makes IndiGo a launch customer for the A320neo. Engine selection will be announced by the airline at a later date.

The A320neo, available from 2016, incorporates new more efficient engines and large wing tip devices called Sharklets delivering significant fuel savings of up to 15 percent, which represents up to 3,600 tonnes of CO2 annually per aircraft. In addition, the A320neo provides a double-digit reduction in NOx emissions and reduced engine noise.

"This order for industry leading fuel efficient aircraft will allow IndiGo to continue to offer low fares," said Rakesh Gangwal and Rahul Bhatia, co-founders of IndiGo. "Ordering more A320s was the natural choice to meet India's growing flying needs. The opportunity to reduce costs and to further improve our environmental performance through the A320neo were key to our decision."

"The A320 Family is the recognised market leader. The A320neo, offering maximum benefit for minimum change, will ensure that this continues to be the case for many years to come," said John Leahy, Chief Operating Officer Customers. "This order positions IndiGo to take full advantage of the predicted growth in Indian air travel and we are delighted that they continue to build their future with Airbus."

The A320 Family (A318, A319, A320 and A321) is recognised as the benchmark single-aisle aircraft family. Some 6,800 Airbus A320 Family aircraft have been ordered and some 4,500 delivered to more than 310 customers and operators worldwide, making it the world's best-selling single-aisle aircraft family. With 99.7% reliability and extended servicing periods, the A320 Family has the lowest operating costs of any single aisle aircraft. The A320neo will have over 95% airframe commonality with the A320 Family whilst offering up to 500nm (950 km) more range or two tonnes more payload.

Image: Airbus A320 jet in IndiGo livery.