Why were airplanes first used mainly for reconnaissance during World War I?

At the outbreak of World War I, airplanes were primarily used for aerial reconnaissance because their early, low-powered engines could carry little more than a pilot and, occasionally, an observer. These aircraft served essentially as extensions of the ground commander's eyes, providing critical intelligence that allowed armies to maneuver effectively, such as during the Battle of the Marne.12

Because most military airplanes at the time were unarmed and lacked the capacity for heavy payloads, they were not yet equipped for offensive combat roles. It was only as the war progressed that technological advancements—such as more powerful engines and the development of specialized weaponry—enabled aircraft to transition into roles like air-to-air combat, ground attack, and strategic bombing.321