Pentagon officials report the Boeing KC-46 refueling tanker is scheduled to take its maiden flight on Friday after eight months of setbacks.

The $50 billion contract for the tanker has been costly for Boeing, with the U.S.-based aviation and security manufacturer taking several unexpected financial hits along the way. This includes an $835 million bill to address design flaws complicating the fueling process, according to the Wall Street Journal.

Budget troubles may be complicated further if Congress decides to pass another long-term continuing resolution, which would tighten funding for defense projects. The U.S. Air Force is expected to ask for an exemption for the KC-46 program. Lt. Gen. Arnie Bunch told Defense News the program remains a top priority for the branch, however officials are giving Congress more time to reach a budget agreement.

"We're hoping it's a short-term continuing resolution," he said at a breakfast hosted by the Air Force Association, "but it will probably be one of the ones that we go back in and look for a waiver to."

The Air Force Association is one of five influential security industry organizations pressing Congress to reach a budget agreement, saying that a long-term continuing resolution does not allow for the industry to provide their best for national security interests.

Boeing's KC-46 tanker is a modified version of the civilian 767 jetliner. It is designed to link up and refuel five different types of Air Force, Navy, and Marine aircraft. Boeing's contract mandates their first delivery is due by August 2017.