The task of keeping the yellow planes with the cheap seats in the sky has fallen to Davis, Polk & Wardwell, which filed a petition for Chapter 11 bankruptcy relief in the U.S. Bankruptcy Court for the Southern District of New York early Monday morning.

Davis Polk has been working with Spirit since at least February, the Wall Street Journal first reported, when a proposed acquisition by JetBlue was blocked by a Massachusetts federal judge. Monday’s filing followed a more recent round of failed merger talks, this time with Frontier Airlines.