Anchorage-based PenAir has halted service to five Oregon and Northern California airports, including Klamath Falls.

The regional carrier filed for Chapter 11 bankruptcy protection in the state of Alaska on Monday, announcing it will begin the process of closing operations in Denver during the next 90 days, pending approval by the Department of Transportation.

Just last October, Crater Lake-Klamath Regional Airport saw resumption of twice daily flights to Portland after losing commercial air service in June 2014.

While the Medford airport saw about a 3 percent bump when United Express departed three years ago, that won't be the case this time.

Airport Director Bern Case said the average of 30 passengers traveling out of Klamath Falls each day amounts to less than 1 percent of Rogue Valley's activity, and could easily be absorbed on present flights.

"We'll certainly benefit," Case said. "But it won't create much of a ripple. It would amount to just over one passenger for our 22 or 23 daily flights. Of course, it wouldn't be evenly distributed."

It was a miracle they got PenAir to come in; they've really had a tough time over there."

What potentially could benefit Medford, and perhaps other regional airports served by Alaska Air Group's Horizon Air, is the availability of PenAir pilots.

Case said PenAir's 30-seat Saab 340 turbo prop aircraft are similar to Horizon's Q-400s.

"They could go through a short orientation and be ready to fly," he said.  "The Horizon pilot shortage is still biting us a bit."

Klamath Airport Manager John Barsalou pushed hard to get TSA to return after the 2014 closure, Case said. "He had to get special legislation to bring them back."

PenAir service has also been discontinued to North Bend; Redding, California; and Arcata, California. The 62-year-old airline said it is filing a Department of Transportation request to end Essential Air Service routes between Crescent City and Portland, as well as regional routes to its Denver hub. The bankruptcy filing will not affect scheduled air service operations in Alaska or Boston.

 — Reach reporter Greg Stiles at 541-776-4463 or business@mailtribune.com. Follow him on Twitter at www.twitter.com/GregMTBusiness, and on Facebook at www.facebook.com/greg.stiles.31