In 2013, France's budget for 50 aircraft was €8.9bn (~US$11.7bn) at a unit cost of €152.4m (~US$200m), or €178m (~US$235m) including development costs. The 2013 French White Paper on Defence and National Security cut the tactical transport aircraft requirement from 70 to 50. As the A400M was unable to perform helicopter in-flight refuelling, France announced in 2016 that it would purchase four C-130Js. In July 2016, French aerospace laboratory ONERA confirmed successful wind tunnel trials of a 36.5 m (120 ft) hose and drogue configuration that permits helicopter refuelling. Prior tests found instability in the intended 24 m (80 ft) hose due to vortices generated by the spoilers (deployed to achieve 108-130 kt air speed).