Southwest, Spirit, Alaska, and JetBlue (and probably others, but I got tired of looking) all have _never_ gone through bankruptcy-- Southwest had even managed

Southwest, Spirit, Alaska, and JetBlue (and probably others, but I got tired of looking) all have _never_ gone through bankruptcy-- Southwest had even managed to turn a profit for 47 consecutive years before COVID came along last year and screwed that streak up. Many of the other big, "traditional" national carriers (including American, Delta, and United) have been through Chapter 11 once. That's not really "trading in the state semi-permanently", though; none of the surviving big-name carriers have been through Chapter 11 more than once, and all are currently out of it.