 These latter aircraft were purchased by the United States Army Air Service, which used them as staff transports and converted one example into an air ambulance.On 28 May 1921, in one of the first major crashes in aviation history, Army Air Service Curtiss Eagle Serial Number "64243", the air ambulance, of the 1st Provisional Air Brigade, crashed during a severe thunderstorm attempting to land at Morgantown, Maryland while returning to Bolling Field, District of Columbia, from Langley Field, Virginia.The pilot, 1st Lt. Stanley M. Ames, and six passengers were killed.