Activist investor Carl Icahn has amassed a 9.91% stake in JetBlue Airways (JBLU 12.69%), and other investors are joining him onboard. Shares of JetBlue opened up 17.2% on Tuesday and were up about 11% as of 10 a.m. ET after the stake was disclosed.A new face in the cockpitJetBlue has been flying through headwinds of late. In 2022, the airline won a bidding war for Spirit Airlines (SAVE -7.44%), but that deal was blocked due to antitrust concerns earlier this year. The airlines are appealing, but in the mean ...