Representational image (Assocaited Press photo)

Flight operations across the Washington DC region resumed on Friday (local time) after a temporary ground stop triggered by reports of a strong chemical smell at a major air traffic control facility.Transportation secretary Sean Duffy confirmed the development in a post on X, saying, “The ground stop is over and operations have resumed.”He added that emergency teams had checked the site and found no danger to staff. “Firefighters from Fauquier County and Prince William County confirm there is no danger to air traffic controllers,” Duffy said.According to Duffy, “The temporary ground stop affected Ronald Reagan Washington National Airport (DCA), Washington Dulles International Airport (IAD), Baltimore-Washington International Airport (BWI) and Richmond International Airport (RIC).”The problem began after employees at the Potomac TRACON facility reported a strong chemical smell inside the building. The centre manages airspace for much of the Washington region. CNN reported that Ronald Reagan Washington National Airport was the hardest hit, with more than 136 cancellations and about 300 delays.Emergency responders and a hazardous materials team later traced the issue to a circuit board that had overheated. The component was replaced.Officials said flights were gradually returning to normal schedules. However, Associated Press reported that flight schedules in the Washington DC area are expected to remain unstable through the weekend.