Capitaine (later Colonel) Henri Joseph Marie Hay de Slade was a World War I flying ace credited with 19 aerial victories. Hay de Slade came from a military family; his father was a naval officer who died in 1908. Hay de Slade began his own military career as a cadet at Saint Cyr in 1913. He transferred to aviation on 13 May 1916, and received his pilot's certificate in August of that year. After further training, he was assigned to Escadrille 80 on 13 December 1916. It wasn't until his reassignment to Escadrille 86 and its Nieuport fighters, on 16 April 1917, that he began to succeed as an aerial warrior. On 20 May, he scored his first victory. He closed out 1917 as an ace; on 5 December, he scored his fifth victory. He would score six more times with Escadrille 86, with his last one comin