Two more F1 teams are on track for pre-season testing late next month.
It has previouslybeen reported that Toro Rosso and Force India had their respective 2017 chassis approved by the FIA following mandatory crash tests.
Now, Brazil's UOL quotes Red Bull designer Adrian Newey as saying: "We have passed the crash tests, the design is almost finished and we are already in production."
And Haas team boss Gunther Steiner said: "Passing the crash test is always a good sign. Once you do that, you know things will come together somehow."
The new season gets underway in March.