Airways and Virgin Atlantic are major purchasers of American-made Boeing aircraft. Flying between the US and UK is at the moment in 2019 supported by the US-EU Open Skies Agreement which came about in 2008, which allows any airline from both countries to fly between each other. New York's John F. Kennedy International Airport is the most popular international destination for people flying out of Heathrow Airport. Approximately 2,802,870 people on multiple daily non-stop flights flew from Heathrow to JFK in 2008. Concorde, British Airways flagship supersonic airliner, began trans-Atlantic service to Washington Dulles International Airport in the United States on May 24, 1976. The trans-Atlantic route between London's Heathrow and New York's JFK in under 3½ hours, had its first operational flight between the two hubs on October 19, 1977, and the last being on October 23, 2003. The two main American intercity bus carriers; Greyhound Lines and during the period from 1999 to 2019 Coach USA, plus their subsidiaries are each owned by a major British transportation company FirstGroup with Greyhound and Stagecoach with Coach USA. Coach USA's budget brand Megabus which started in 2006, itself is a copycat of the British version of the discount coach company that started in 2003. In 2022, Britain announced that it would cease flights to the US over the problems with 5G network towers. It appears that the towers can interfere with the aircraft systems. State and official visits In the 20th century, there were 78 formal and informal summits bringing together the president and the prime minister to deal with an agreed-upon agenda. The first was 1918, the second in 1929. The rest began in 1941, which marked the decline of ambassadors as the key transmitters of policy discussions. In three out of four of the summits, the British delegation traveled to America. Summits have become much less important in the 21st century, with its new communication modes. State visits involving the head of state have been made over the years by four presidents and two monarchs. Queen Elizabeth II has met all the presidents since Truman except Johnson (Queen Elizabeth II would have met Johnson had he not been hospitalized with the influenza when Churchill died; he very much wanted to attend the funeral and had arranged to meet her privately after the funeral.). In addition, the Queen made three private visits in 1984, 1985, and 1991 to see