Aviation enthusiast and reporter Zach Griff used flight schedule data to map out the busiest times at border control in Schengen airports

Aviation enthusiast and reporter Zach Griff used flight schedule data to map out the busiest times at border control in Schengen airports

The new Entry/Exit System, known as EES, has been slowly rolled out across Europe - and a major airline has warned this summer could be affected by delays as a result.

The budget airline called for more flexibility around the EU entry-exit system until problems are fixed