Airbus continues expansion as four airlines fly unpopular A220-100

Despite these developments, the smaller A220-100 remains relatively unpopular compared to its larger counterpart. Four airlines currently operate this model: Bulgaria Air, Delta Air Lines, ITA Airways, and SWISS. These carriers have two, 45, twelve, and nine units of the type respectively.

Delta Air Lines holds the largest fleet of A220s globally with a combination of both variants. Initially ordering up to 125 CSeries CS100s in April 2016 from Bombardier—a deal which faced trade disputes—the airline eventually received its aircraft after tariffs were resolved.

SWISS was initially a launch customer for the A220-100 when it introduced its first CS100 at Zurich Airport in July 2016. "It was about a year ago that a Bombardier C Series aircraft first touched down on Swiss soil," SWISS stated at that time.

ITA Airways acquired twelve A220-100s configured entirely in economy class with plans to utilize them on short European routes.

Overall, while operators recognize certain advantages such as reduced costs associated with flying smaller aircraft like the A220-100 on specific routes or airports that impose size restrictions—such as London City Airport—most continue favoring larger models due to better passenger load capabilities despite potential savings offered by smaller planes like those within Airbus' range.