His citation in May 1916 mentioned that he "has always given proof of a noteworthy spirit; has constantly set the example of courage to the other drivers, and has been an invaluable assistant to the commander of his Section".

[5]: 325 [6] During his ten-month stay at the Western Front of the World War I as a fighter-pilot, Sergeant Walter Lovell flew near daily Nieuport 17 and Spad VII aircraft on different missions, mostly behind the enemy line, eventually becoming Lafayette Escadrille's adjutant.

[5]: 327  Lovell left the Lafayette Escadrille on October 24, 1917, for General Headquarters of the American Expeditionary Force at Chaumont after his medical test indicated a hearing loss and color blindness,[10] which kept him behind a desk for the balance of the war.

In the Lafayette Escadrille, Lowell was not alone in his physical deficiency since the medical board discovered to its surprise that Raoul Lufbery did not have a proper sense of balance, William Thaw, Charles Dolan and Dudley Hill had poor vision in one eye, and Henry Jones had flat feet, which did not stop them from becoming celebrated World War I fliers.

[5]: 327 Lovell resigned his commissions in January 1919 at Washington, D.C., and took residence in Paris, where he had married Helėne Du Bouchet on April 16, 1918, in the American Church on Rue de Berri.