Group 1 - United Airlines and JetBlue's partnership, named "Blue Sky," has received approval from the U.S. Department of Transportation (USDOT) [1] - The partnership is not a merger but an agreement allowing JetBlue to provide United access to slots at JFK International Airport for up to seven daily round-trip flights starting in 2027 [2] - JetBlue and United will exchange eight flight timings at Newark as part of a net-neutral exchange [2] Group 2 - The partnership was pursued by JetBlue after a federal judge blocked its alliance with American Airlines in 2023 [5] - Spirit Airlines has urged USDOT to reject the collaboration, claiming it is anticompetitive and could lead to similar deals among other large carriers [7] - JetBlue and United plan to share more details about the implementation of the Blue Sky collaboration in the coming weeks [7]