Ryanair has renewed its call for urgent reform to Europe’s air traffic control (ATC) systems as strikes by French ATC staff extend into a fourth consecutive day. The budget airline says more than 400 of its flights have been cancelled this week, which has affected over 70,000 passengers during the height of the summer travel season.

View of the air traffic control tower of the Marseille-Provence airport on the eve of a strike call by two air traffic controllers' unions to defend their working conditions, in Marignane, near Marseille,

Ryanair publicly called on the European Commission Thursday to reform EU Air Traffic Control services as strikes by French ATC employees have canceled flights for more than 30,000 people.