The 11th Aero Squadron was a Air Service, United States Army unit that fought on the Western Front during World War I. The squadron was assigned as a Day Bombardment Squadron, performing long-range bombing attacks on roads and railroads; destruction of materiel and massed troop formations behind enemy lines. It also performed strategic reconnaissance over enemy controlled territory, and tactical bombing attacks on enemy forces in support of Army offensive operations. After the 1918 Armistice with Germany, the squadron returned to the United States in May 1919 and became part of the permanent United States Army Air Service in 1921, being re-designated as the 11th Squadron (Bombardment) .