"The A220 will serve as the cornerstone of our future domestic growth." Delta CEO Ed Bastian, October 26, 2018.

• First U.S. airline to take delivery of the Airbus A220, formerly known as the "Bombardier C Series."
• First U.S. airline to operate the Airbus A220.
• Delta is the largest A220 operator in the world.

In April 2016, Delta was the U.S. launch customer for the Bombardier C Series, placing an order for 75 CS100 aircraft. The more fuel-efficient mainline aircraft offered Delta added network flexibility. 

Since 2009, Delta had retired 280 50-seat regional jets and more than 130 older, narrowbody aircraft, while refreshing its fleet with over 300 aircraft.

“As we reshape our fleet for the future, the innovative onboard experience of the C Series is a perfect complement for the top-notch service provided every day by Delta people,” said Ed Bastian, Delta’s incoming CEO in 2016. “These new aircraft are a solid investment, allowing us to take advantage of superior operating economics, network flexibility and best-in-class fuel performance.” 

In July 2018, Airbus rebranded the Bombardier C Series as the A220, after acquiring a new majority stake in the product line. Delta accepted delivery of its first A220-100 (N101DU) on October 26, 2018.

• Best-in-class fuel performance for narrowbody, single-aisle aircraft. 
• State-of-the-art interior featuring seat-back screens in all cabins, Gogo 2Ku Wi-Fi, and among the widest seats of any narrowbody aircraft (18.6 inches seat width in the Main Cabin).
• Other cabin innovations: largest windows in the narrowbody, single-aisle market, high-capacity overhead bins with the largest stowage in its class, and full-spectrum LED ambient lighting
• Best-in-class fuel performance for narrowbody, single-aisle aircraft.

With Pratt & Whitney’s latest geared turbofan PW1500G engine, advanced technology and composite materials, the CS100 offered 20 percent improvement in fuel efficiency over similar-sized, single-aisle aircraft, as well as reduced noise and emissions. With the order of the C Series, Delta would no longer induct the Embraer E190 into its fleet as planned.

Schedule for Delta's initial A220-100 service on 2018 top domestic business routes:

• New York-LGA to Boston and New York-LGA to Dallas/Ft. Worth (January 2019)
• Detroit to Dallas/Ft. Worth (March)
• New York-LGA to Houston-IAH (April)
• Salt Lake City to Dallas/Ft. Worth (May)
• Minneapolis/St. Paul to Dallas/Ft. Worth (June)
• Houston-IAH to Detroit & Minneapolis/St. Paul and Houston-IAH to Salt Lake City
• New York-JFK to Dallas/Ft. Worth (August)

In 2020, Delta kept all A220s flying in the midst of the Covid-19 pandemic crisis, even while parking some of every other aircraft type in the fleet (and retiring older types).

The A220-300 was the first stretched version of the A220. In 2020, Delta added this larger variant of the A220-100 with room for 130 passengers: 12 First Class, 30 Comfort+ and 88 Main Cabin.

Delta A220-300, N302DU, was the first aircraft assembled by Airbus in Mobile, Ala. It exited the paint shop on March 3, 2020.

Delta's A220-300 inaugural operated on November 17, 2020 from Salt Lake City (SLC) to Houston (IAH). The inaugural flight was intended to operate the previous day (November 16 as Flight 223, the aircraft code for the A220-300) but was postponed due to delay with the ferry flight from Atlanta to SLC.