when the Bureau of Air Commerce temporarily grounded the airline's Boeing 247s. The six B-247s were all sold off in 1937. The airline's 15 B-247Ds were all gone by the end of 1942. Two remain in museums today — one at the National Aviation Museum at Ottawa, Ontario, Canada, and another, the City of Renton, in flying condition at the Museum of Flight, Boeing Field, Seattle, Washington. PCA, based at the new Allegheny County Airport near Pittsburgh, continued to add routes, notably to Chicago in 1938, and aircraft, notably the Douglas DC-3, in 1940. In 1941 PCA moved its headquarters to the new Washington National Airport in Arlington, Virginia, becoming one of its three original tenants; PCA had been consulted during the airport's design. The row of office buildings next to its hangars became "mahogany row" and the airline adopted the slogan "The Capital Airline", with its aircraft dubbed "Capitaliners". In September 1943 Pennsylvania Central requested the CAB authorize new routes affecting 23 states indicating plans for a major expansion after the war. PCA even had big trans-Atlantic ambitions. PCA did see expansion as the war wound down. The company signed contracts with Douglas Aircraft for DC-4s, on September 28, 1944, worth $10 million. In 1946 PCA began flying the Douglas DC-4 but found the airplane was unprofitable on some of its low volume short segment routes. One of PCA's DC-4s had been used to transport President Roosevelt to the Casablanca Conference during World War II Ten DC-4s still served Capital at the time of the UAL merger. All were immediately disposed of by United. By 1946, the combination of expansion and post-war inflation were financially pressing United States airlines. PCA was facing stronger competition on the essential New York to Chicago route. By the end of the first quarter of 1947 Pennsylvania-Central was in such a bad situation that the company president had to seek S.E.C. approval for a refinancing agreement with PCA's bankers. The crisis led PCA to the election of J.H. "Slim" Charmichael as president, and drastic cuts from 4,800 employees to 3,000. By October 1, 1947, PCA had 25 DC-3s (two cargo only) and 3 DC-4s. "We had a sick airline on our hands, and we had to get it out of bed, but quickly. We figured our best chance lay in leading not just following the others", Charmichael told the New York Times. The cuts