An engineering student who spoke fluent French and English, he was a fine draughtsman, and was studying in Paris when the war broke out, but managed to return to Germany and was assigned to the Reserve Jäger Bataillon 7 in Bückeburg.

Requesting flying duties Schäfer trained as a pilot and served over the Eastern Front with Kampfgeschwader 2 from July 1916 onwards.

With just this single victory, he impudently telegraphed Manfred von Richthofen, who was assembling a "top gun" (kanone) squadron at Jasta 11, "Can you use me?"

In intensive operations during Bloody April he became a flying ace, being credited with 21 victories and awarded the Pour le Mérite.

[1] Somehow amidst all this he found time to pen his autobiography, Vom Jaeger zum Flieger ("From Soldier to Pilot").