Which event in 1914 marked the beginning of military aviation?

The event in 1914 that marked the beginning of military aviation is the use of aircraft during World War I. This era represented a significant shift in the perception and application of aircraft, as they transitioned from being experimental machines primarily focused on civilian purposes to becoming critical assets in warfare.

During World War I, various nations began to realize the potential of airplanes for reconnaissance, ground support, and, eventually, aerial dogfighting. This marked the true inception of military aviation, as countries developed strategies and tactics around aircraft, leading to the establishment of air forces and specialized training programs for pilots. As the war progressed, aircraft technology advanced rapidly, driven by the immediate needs of military engagement, establishing the foundation for the future of aerial warfare.

In contrast, the other events listed did not specifically relate to military aviation in such a direct way. The Wright brothers' first flights were essential to the foundations of aviation but occurred significantly earlier, and while the first transatlantic flight demonstrated the capabilities of aircraft, it was primarily a civilian achievement. The launch of the first jet aircraft came much later, well after World War I, and represented a different phase in aviation development altogether. Thus, the use of aircraft during World War I stands out as the definitive moment