Ewald was born on 26 March 1911 in Hamburg, at the time a sovereign state of the German Empire.

[3] On 1 November 1938, I. Gruppe (1st group) of Jagdgeschwader 433 (JG 433—433rd Fighter Wing) was formed at the Ingolstadt-Manching Airfield, 60 kilometers (37 miles) north of Munich.

Initially the Gruppe was placed under the command of Hauptmann Dietrich Graf von Pfeil und Klein-Ellguth and equipped with the Messerschmitt Bf 109 D-1 fighter aircraft.

[9] On 28 June, German forces had launched Case Blue, the strategic summer offensive in southern Russia.

That day, Ewald claimed two aerial victories with the Gruppenstab, a Lavochkin-Gorbunov-Gudkov LaGG-3 fighter and a Petlyakov Pe-2 bomber.

[12] On 14 July 1943 during the Battle of Kursk, Ewald was shot down in his Bf 109 G-6 (Werknummer 20220—factory number) by Soviet flak 20 kilometers (12 miles) northeast of Belgorod.

Following World War II, Ewald joined the post-war German Air Force, at the time referred to as the Bundesluftwaffe, attaining the rank of Oberstleutnant (lieutenant colonel).

[16] Spick also lists him with 78 aerial victories claimed in an unknown number combat missions.

This number includes one claim during the Spanish Civil War, one over the Western Allies, and 63 on the Eastern Front.