The Airco DH.9A is a British single-engined light bomber that was designed and first used shortly before the end of the First World War. It was a development of the unsuccessful Airco DH.9 bomber, featuring a strengthened structure and, crucially, replacing the under-powered and unreliable inline 6-cylinder Siddeley Puma engine of the DH.9 with the American V-12 Liberty L-12 engine.