FlyDubai, the lower-cost sister airline to long-haul carrier Emirates, announced an initial order Tuesday for 150 Airbus A321neo aircraft at the Dubai Air Show — an estimated $24 billion purchase that will see the carrier for the first time expand its fleet beyond Boeing.

The deal would more than double FlyDubai's current fleet of aircraft and the airline said it had options to buy another 100 A321neos. It also represents a major purchase for the airline as Dubai prepares across both carriers to expand as it builds a five-runway airport in this desert sheikhdom in the United Arab Emirates.