They are vapour trails, not contrails or chemtrails and occur above a certain height with all aircraft that can reach this height, jet, turboprop or piston engined aircraft.

I know that stratospheric aerosol injection is real but these are contrails. Holland has very many intercontinental flights crossing its boundaries, post a picture of these and everyone shouts chemtrails parrot fashion.

Source: 40 years as an aircraft fitter on a lot of types, both military and civilian.