IndiGo is likely to convert its purchase rights for 40 Airbus A350 family aircraft into a firm order. This comes just months after India’s largest airline by market share had placed a firm order for 30 A350-900 aircraft and bagged an option for an additional 70. In June, IndiGo converted the option to purchase 30 aircraft into a firm order, the Economic Times reported. The development comes around a time when India’s largest carrier is gradually expanding in global skies.