The Air Force says the struggling KC-46 tanker program has completed the final tests needed for delivery

US Air Force

A KC-46A Pegasus tanker takes off from Boeing Field, Seattle, June 4, 2018.

Boeing's KC-46 Pegasus aerial-refueling tankers have completed their final flight tests ahead of the deliver of the first aircraft in late October, the US Air Force said on Friday.

"With this milestone complete, the test program has demonstrated a level of maturity that positions Boeing to deliver, and the Air Force to accept, an aircraft by the end of October 2018," Will Roper, an Air Force service acquisition executive, said in a release.

The test team, made up of personnel from the Air Force and Boeing, completed all test points for the Remote Vision System, which the plane's crew uses to guide the refueling boom, and for the receiver qualifications of the F-16 fighter jet and the C-17 Globemaster cargo aircraft.

Those two receiver qualifications come after testing in June when the KC-46 received fuel from a KC-135 tanker, and those three tests are the minimum required for deliver.

The years-long KC-46 program was originally scheduled to deliver 18 planes and additional materials by August 2017, but the $44 billion initiative has hit numerous setbacks and delays.

Boeing/John D. Parker

A KC-46 Pegasus refuels an A-10 Thunderbolt II, July 15, 2016.

Earlier this year, the Air Force said it expected Boeing to miss the October deadline to deliver the planes, with the first tanker not arriving until the end of the year and all 18 planes by spring 2019.

In June, Boeing and the Air Force reached an agreement to deliver the first aircraft by October, two months earlier than the Air Force expected. Air Force Undersecretary said at the time that the new timeline was "aggressive but achievable."

The KC-46 program now moves to follow-on receiver aircraft testing and certifications required for operational testing, which will start in 2019.

Air Force Chief of Staff Gen. David Goldfein visited the KC-46 testing team in June, where he flew the aircraft during a test flight and observed C-17 receiver-aircraft certification testing.

"I am encouraged by the team's progress in putting another significant milestone behind us," Goldfein said. "The collective Air Force, Boeing, Federal Aviation Administration, and Defense Contract Management Agency team is laser-focused on the remainder of activities needed to certify and accept this much-needed tanker in late October."

(Reporting for Reuters by Sanjana Shivdas in Bengaluru; editing by Arun Koyyur)