Frontier Airlines is trying to merge with Spirit -- again / Seat fees, Frontier thieves, and Spirit's last hurrah: Airlines news roundup / Several airlines suspend flights to Haiti after JetBlue and Spirit planes hit by gunfire / Spirit tumbles to record low on report it's exploring a bankruptcy filing. Here's how it got here / From Southwest to Spirit, budget airlines are in a tailspin / Boeing delays, Alaska and Spirit's paydays, and United's rough landing: Airline news roundup / JetBlue and Spirit end merger deal / JetBlue and Spirit abandon their decision to merge after it was blocked by a judge / JetBlue casts doubt on Spirit deal completion / Budget airlines like Spirit and Ryanair make up almost a third of global airline capacity. Here's how they do business