United Airlines and JetBlue have initiated a significant customer benefit through their 'Blue Sky' collaboration, allowing members of both airlines' loyalty programs to earn and redeem miles across each other's networks. This new partnership provides JetBlue's TrueBlue members access to United's extensive global network, including United Express flights. Conversely, United's MileagePlus members can now earn and use their miles for flights on JetBlue, which is well-known for its leisure travel destinations. The reciprocal loyalty benefits are designed to enhance the travel experience and provide more options for the frequent flyers of both airlines. The redemption of miles is subject to seat availability on each carrier's booking platforms.