U.S. Transportation Secretary Sean Duffy on Thursday will call for tens of billions of dollars to overhaul America’s strained air traffic control system to address crumbling infrastructure, dramatic staffing shortfalls and failing technology.

Amid safety concerns from a spate of plane crashes and near misses, President Donald Trump says a planned massive overhaul of the U.S. air traffic control system will revolutionize the air industry.

President Donald Trump’s own policies have prompted departures of key staff and hurt morale at the aviation agency, complicating multi-billion dollar modernization plans.