A World War I flying ace credited with five aerial victories as a bomber pilot, he flew a Breguet 14.

[1] As a professional officer, he remained in the French Air Force after World War I[citation needed] and he also competed at the 1924 Summer Olympics as a sabre fencer.

[2][3] During World War II, he held the rank of general and served as Minister of Air in Vichy France from 1942 to 1943.

Then, on 14 September 1918, Jannekyn and Weismann were one of four Bréguet air crews battling German Fokker D.VIIs.

[1] Chevalier de la Légion d'Honneur"An officer of exceptional merit who has never ceased throughout the war, at first as a volunteer in a cavalry battalion, then in day bombardment aviation, to be an example of courage and self-denial.