Frontier Airlines (F9, Denver International) is shifting much of its existing capacity from its Chicago O'Hare base to Chicago Midway marking its return to the second-busiest airport in the Chicago metropolitan area after a seven year absence. From April 28, the budget carrier will operate out of both Chicago airports, although Midway will become its primary Chicago gateway. As such, eight of 10 routes will shift from O’Hare to Midway, leaving O’Hare with Frontier Airline service to just four destinations: Cancún, Mexico; Orlando International, Florida; Punta Cana, Dominican Republic; and San Juan Luis Muñoz Marin, Puerto Rico.

Punted by the airline in a statement as an expansion in Chicago that complements its existing service at O’Hare, new routes from Chicago Midway International Airport include:

This means, from April 26, Frontier Airlines services from O'Hare to Denver, Las Vegas, and Phoenix are terminated, the ch-aviation schedules module reveals, while services from O'Hare to the following destinations will no longer be launched: Atlanta, Dallas Fort Worth, Ontario, Tampa, Trenton, Salt Lake City, and St. Louis Lambert International.

In addition, the airline announced new routes from Houston Hobby:

The move to Midway and Houston Hobby puts Frontier Airlines in direct competition with Southwest Airlines (WN, Dallas Love Field), which has the lion share at both airports, including 93% of weekly airline seat capacity at Midway and 95% at Houston Hobby, according to the ch-aviation capacities module. Delta Air Lines (DL, Atlanta Hartsfield Jackson) and Allegiant Air (G4, Las Vegas Harry Reid) also hold a substantial market share at both airports.

“We’re excited to strengthen our position in two of the five largest metro areas in the country with 13 new routes and two additional airport options for our customers flying to or from Chicago or Houston,” said Frontier Airlines Senior Vice President (Commercial) Daniel Shurz. “This strategic announcement situates Frontier to capture strong existing demand and stimulate new traffic,” he added.

The airline operates 111 Airbus family aircraft including sixteen A320-200s, seventy-four A320-200Ns, and twenty-one A321-200s. It has 233 aircraft on order, comprising fifty-seven A320-200Ns, 158 A321-200Ns, and eighteen A321-200NY(XLR)s, ch-aviation fleets data shows.