Senate attempts new maneuver to block Turkey from getting stealth jet

F-35A Lightning II aircraft receive fuel from a KC-10 Extender tanker aircraft from Travis Air Force Base, Calif., during a flight from England to the United States, July 13, 2016. Air Force photo by Staff Sgt. Madelyn Brown

Washington (CNN)US senators have launched a new effort to block the transfer of F-35 Joint Strike Fighters to Turkey, a move that comes just minutes after Turkey was scheduled to receive its first jets as part of an official ceremony in Fort Worth, Texas.

A bipartisan group of lawmakers has added an amendment to the Senate's appropriation bill for the State Department and foreign operations that would prohibit the use of State Department, foreign operations, and related program funds from being used "to transfer, or to facilitate the transfer of, F-35 aircraft to Turkey," unless the secretary of state certifies that Turkey will not purchase the Russian-made S-400 anti-aircraft missile system.
Although Turkey has long been a participant in the development of the F-35 program, senators have sought to block Turkey from receiving the stealth warplanes amid a deterioration of the US-Turkey relationship and concerns over Ankara's purchase of the Russian-made anti-aircraft system.
    Their efforts have drawn criticism from Turkey and resistance from the Pentagon, but a US defense official told CNN that the concern is that the Russian-made S-400, particularly if it's plugged into Turkey's integrated air defense system, could gather technical data on the F-35's capabilities and that critical information could be passed to Moscow either intentionally or unintentionally through a back door in the Russian designed system.

    'It's totally nuts'

    Those worries were echoed by senators sponsoring the bill.
    "The concern is that the F-35 is the most advanced aircraft, the most advanced NATO aircraft, and if Turkey goes forward with the acquisition of the S-400, it will allow the Russians to collect information on how to best attack an F-35 fighter," Sen. Chris Van Hollen, a Maryland Democrat and one of the amendment's co-sponsors, told CNN.
    "It's totally nuts to hand the Russian the keys to the mission capabilities of the F-35 and allow them to try to detect and then exploit any vulnerabilities," he added.
    Turkey will technically take ownership of the warplanes on Thursday, but the US will retain custody of the jets while Turkish pilots and maintainers are being trained on the new planes at Luke Air Force Base in Arizona.
    A US defense official told CNN that this training program could take one to two years to complete, meaning congressional efforts to block the transfer could still succeed during this period, despite Thursday's ceremony.
    A US official familiar with the process tells CNN that because Turkey is a member of the F-35 consortium, the State Department funding is not involved in the transfer of the aircraft and that the Department of Defense is the lead US agency. While this calls into question the impact of Thursday's amendment, a significant section of Congress appears intent on blocking the transfer anyway it can.
    But a Democratic congressional official argued that the funding block could have an impact, noting that it would prevent the administration from issuing the necessary permits that would allow the planes to actually leave the US. The official also said the State Department played a critical role in approving and facilitating the transfer of every supporting article for the F-35 program
    "There's no way to continue with this transfer without State D