The Air Force’s next aerial refueling tanker made history on Friday by making its first takeoff as a KC-46A Pegasus.

The Boeing– [BA] developed aircraft took off at roughly 4:24 p.m. EDT, according to company spokesman Chick Ramey, who said the flight is slated to last four hours. The tanker was originally set to take off around 1 p.m. EDT. Takeoff was from Paine Field in Everett, Wash., while landing is set for Boeing Field in Seattle.

Ramey said early Friday Boeing and the Air Force would perform multiple tests, including trying to take the tanker to 35,000 feet altitude, check basic integrity and how it handles, as well as exercise systems. They will also check engine acceleration and deceleration and the autopilot system.

The next flight, which could come as early as next week, is when the Air Force and Boeing will check out the aerial refueling boom, Ramey said. On this flight, the two stakeholders will check the wing aerial refueling pods, conduct post flight inspection and calibrate instrumentation. Ramey said Milestone C testing is when the Air Force and Boeing will perform actual aerial refueling.

The first flight of the KC-46 is good news for Boeing, which has been taking heat for delays to the fixed-price program. Boeing in July announced it took a $536 million after-tax charge related to work on the tanker’s integrated fuel system that arose when the company was preparing for and conducting test and verification of the system during the second quarter (Defense Daily, July 17).