According to a report presented to the US Congress, F-35 is experiencing problems in the production process by excluding Turkey from the program. According to the report of the US Government Accountability Office / GAO, while the mass production process is speeding up, the failure to supply the parts both slows down the process and increases the cost. According to the report, in July 2018, 875 pieces were missing a month. This amount reached 8 thousand in July 2019. The same 20 sub-supply companies provide 60 per cent of the parts with supply shortages.