Waddington entered the army on December 15, 1914. While serving with an infantry regiment, he was promoted to Caporal in June of 1915. A month later, he transferred to the French Air Service and was assigned to N67. Promoted to Sergent in March of 1916, Waddington began training to become a pilot in September, receiving a Pilot's Brevet on January 26, 1917. Following additional training, he was assigned to N12 where he achieved his first victory by shooting down a two-seater. In March of 1918 after two more promotions, he was reassigned to Spa154 where he shot down five enemy balloons in addition to several other enemy aircraft. Reassigned in September of 1918, Waddington ended the war with Spa31 where he scored his twelfth and final victory.

Chevalier de la Légion d'Honneur
"Officer pilot of great bravery and rare audacity, combined with magnificent skill and coolness. On September 29, 1918, he reported his tenth victory by downing a scout in flames during the course of an extremely difficult combat with several enemy pursuit planes. Following the combat, he was forced to land in our front lines with his plane riddled by bullets." Chevalier de la Légion d'Honneur citation, November 9, 1918