The nation?s air traffic controllers went back to work on Friday, ending a two-day walkout that disrupted air travel at all Dominican airports. The Diario Libre reported that because the military controllers were handling the daily flights in a ?precarious manner,? the civilian flight controllers decided to come to an understanding with the head of the Civil Aeronautical Board, Carlos Alvarez Guzman, for ?reasons of national security.? Alvarez Guzman promised both ?verbally and morally? to study the series of demands made by the air traffic controllers.