The fifth-generation stealth fighter jet program is back on track, the head of Turkey's defense industry told Anadolu Agency (AA). "There were really a lot of question marks about the program, in terms of its budget and timespan. There were various criticisms about the program," Defense Industry Undersecretary Ismail Demir said following his trip to Luke Air Force Base in Phoenix, Arizona, where he attended a series of annual high-level meetings on the F-35 Joint Strike II program, of which Turkey is a partner. "So, the significance of this meeting was we saw that most of those question marks have been eliminated, and both the partner countries and the United States can see the future of the program now," he said, adding: "The program is back on track. The next step in front of us is the issue of delivery and logistical support for the operational fighters."

Senior Pentagon officials told the U.S. congress last month that they did not expect "a major design problem" in regards to the stealth aircraft. The U.S. Defense Department's director of operational tests and evaluation, Michael Gilmore, said in March that the program would be delayed by six months to one year due to the problems with stability systems, sensors and information diffusion systems. The program is still expected to deliver 100 aircraft in 2019 and 145 by 2020.

Lockheed Martin's F-35 Lightning II with its fifth-generation advanced stealth and firepower technology - one of the Pentagon's costliest projects - has 11 partner countries including, , Australia, Canada, Denmark, Israel, Italy, Japan, the Netherlands, Norway, South Korea, Turkey and the United Kingdom. The projected cost is about $380 billion, according to the Governmental Accountability Office. Partner countries will share the costs proportionate to their aircraft order. Two aircraft will be delivered to Turkey in 2018, of a total order of 107, according to Demir.

He added that the modernization and upgrades of the aircraft would continue after the delivery, noting that several Turkish companies are producing certain complicated parts of the F-35's engine. "Turkey is selected as the first headquarters for the maintenance, repair and assembly of the engine for F-35 outside of the U.S.," Demir said.