Delta and Airbus announced Tuesday that Delta has agreed to expand its Airbus A220 order book by five aircraft to a total of 95.

Delta now expects to take delivery of 45 A220-100s and 50 A220-300s during the next four years, with the first -300 variant expected in 2020 coming from Airbus’s Mobile, Alabama final assembly line.

This week, Delta began flying the amenity-rich A220 from its Seattle hub, and will offer as many as 74 daily departures from 10 airports this summer.

In a separate arrangement, Airbus and Delta have signed a non-binding memorandum of understanding for Delta TechOps to provide A220 component repair and material services for Airbus’ A220 Flight Hour Services maintenance-by-the-hour program. This strategic partnership will allow Airbus to further enhance its successful Flight Hour Services program for the A220 by building on Delta Tech Ops’ proven component repair and management capabilities and on Airbus’ expertise in maintenance engineering, inventory management and innovative services solutions.

As the largest aviation maintenance group in North America, Delta TechOps highly skilled workforce of over 10,000 technicians, engineers and other support employees provide full-service maintenance to more than 850 Delta aircraft and their engines as well as maintenance services to more than 150 other operators, cargo operators and the Military & Government, through the airline’s MRO business.