United Airlines and JetBlue's partnership, known as "Blue Sky," has been cleared for takeoff following a review by the U.S. Department of Transportation (USDOT).  "Blue Sky is a new and unique collaboration designed to give customers of both airlines even more options to find flights that fit their plans as well as new opportunities to earn and use MileagePlus® miles and TrueBlue points across both airlines," United said in a media release on Tuesday. The partnership is not a merger of the airlines, but an ...