(Reuters) – The U.S. Defense Department is poised to approve the first trans-Atlantic flight of Lockheed Martin Corp’s F-35 fighter jet in July, when the new warplane is expected to take part in two international air shows near London, according to multiple sources familiar with the issue.

U.S. Defense Secretary Chuck Hagel is “very close” to a decision that would allow two or three F-35s to fly at the Royal International Air Tattoo, or RIAT, an annual military air show outside London, and the larger Farnborough air show, held every two years, said the sources, who were not authorized to speak publicly.

Britain, which contributed $2 billion to the development of the new radar-evading fighter jet and plans to buy 138 F-35s in coming years, asked for the jet’s participation to help showcase the increasing maturity of the new radar-evading plane. Britain was also the first international partner on the program.

Details of the F-35’s international debut are being worked out, including how much it will cost to fly the planes to London and who will pay for it, but no issues have emerged to prevent the appearances, the sources said.

The costs will likely be shared by Britain, the Pentagon’s F-35 program office, the U.S. Marine Corps and industry.

Lockheed and Britain’s Ministry of Defense declined comment. Officials at the F-35 program office had no immediate comment.

“Having the aircraft front and center on the UK stage will focus attention on the fact that it’s a fairly mature program at this point, with over 100 jets built,” said one of the sources.

British Defense Secretary Philip Hammond is due to meet with Hagel during a visit to the United States this week, but they are not planning an announcement about the F-35’s UK debut, said one of the sources.

Current plans call for at least one of the participating F-35s to be one of the three F-35 B-model jets already built for Britain, with a UK pilot at the controls.

Participating in the international air shows will allow the Pentagon’s F-35 program to carry out additional training and learn how the plane’s logistics, maintenance, aerial refueling, and security systems work overseas, the sources said.

“This will be an opportunity to learn real-world lessons and allow additional time to resolve any problems before the first airplanes are delivered overseas,” said one of the sources.

Lockheed and Britain’s Ministry of Defense declined comment. Officials at the F-35 program office had no immediate comment.

Lockheed is the main contractor on the $392 billion F-35 Joint Strike Fighter, the Pentagon’s costliest weapons program. Northrop Grumman Corp and Britain’s BAE Systems are the biggest suppliers.

Pratt & Whitney, a unit of United Technologies Corp, builds the single engine that powers the plane. Britain’s Rolls Royce Group builds the lift fan that enables the B-model of the F-35 to land like a helicopter.

Boeing Co’s F/A-18 Super Hornet fighter jet is also due to fly at the RIAT air show.

SOURCE REUTERS.