Delta Air Lines has ordered 15 additional A220 aircraft, bringing the total to 90.

The additional orders are the airline’s first for the -300 model.

Delta also converted earlier A220 orders to the larger -300, bringing to 50 the number of A220-300s on order.

“These additional A220 aircraft will continue to strategically enable Delta to refresh our fleet, drive further advances in the customer experience and serve as an excellent investment for our customers, employees and shareowners for Delta into the next decade,” said Gil West, Delta chief operating officer.

“We look forward to taking our first A220-300 in 2020 at the Airbus assembly facility in Mobile, Alabama.”

Delta placed its initial order for 75 aircraft in 2016.

After much wrangling over tariffs, the first Canada-built plane was delivered last year.

Airbus will produce the A220-300s at a new US assembly facility in Mobile, Alabama.

Construction of the plant, to be located adjacent to the existing Airbus A320 assembly facility, will begin later in January.

“Delta has always been deeply focused on the passenger experience, and the A220 fits perfectly with that philosophy,” said Christian Scherer, Airbus chief commercial officer.

“You just need to take a look at Delta’s cabin on the A220 to see it’s setting a new standard in short-haul flying.

“The A220 will provide passengers with a level of comfort and convenience that makes flying a pleasure again, while meeting Delta’s high standards for efficiency and reliability.”

The A220 is the only aircraft purpose-built for the 100-150 seat market.

With an order book of more than 500 aircraft to date, the A220 hopes to win a large share of the 100- to 150-seat aircraft market estimated to represent at least 7,000 aircraft over the next 20 years.