WASHINGTON, Aug. 23 -- The air over Reagan National Airport fell quiet for three hours on Sunday as the Federal Aviation Administration suspended departures and arrivals to accommodate Washington's first-ever IndyCar street race, and a presidential lap of honor that no one on the grid could match for sheer spectacle.

Donald Trump, dressed in a white polo and aviator sunglasses, climbed aboard the presidential state car universally known as the Beast and drove a ceremonial lap around the Freedom 250 circuit carved through the National Mall, waving to the tens of thousands who had gathered along the barriers. The crowd noise crested as he reached the finishing straight in front of the Capitol, a moment that required the FAA to ground civil...