Mesa Air Group Inc. filed for Chapter 11 bankruptcy protection Tuesday, citing an untenable financial situation. The Phoenix-based regional airline is asking a federal bankruptcy court to allow it to continue flying and operating during its reorganization. Mesa, which flies regional routes for several large carriers, operates 130 airplanes and serves 127 cities, including Des Moines.

“This process will allow us to eliminate excess aircraft to better match our needs and give us the flexibility to align our business to the changing regional airline marketplace, ensuring a leaner and more competitive company poised for future success,” Mesa Chairman and CEO Jonathan Ornstein said in a release.

The troubled regional operator said in court filings that 52 of its 130 aircraft are parked and that it needs to retire an additional 25, according to Reuters. The company operates independently as Mesa Airlines, but the bulk of its operations involve code-sharing flights with major partners Delta Air Lines, US Airways and United Airlines.

At Des Moines International Airport, Mesa currently operates four flights per day to Phoenix as US Airways Express and two flights per day to Chicago as United Express. Airport spokesman Roy Criss said Mesa has eliminated four of its daily United Express flights since December. Whether Mesa reduces more flights serving Des Moines depends on contract negotiations between the company and the larger airlines, he said.

“We’re not involved in those negotiations, so we have no way of knowing whether that’s going to result in a reduction in flights,” he said.

Mesa reported assets of $975 million and liabilities of $869 million as of Sept. 30, according to court filings, reported ATW Daily News, an industry newsletter. Canadian-based Bombardier Inc. is Mesa’s largest creditor; the airline owes the aircraft manufacturer more than $130 million.