Which ethnicity was the pilot, who is credited with 258 aerial victories flying the Jagdgeschwader 54, identified as?
Austrian-born
Title: Walter Nowotny
Passage: Walter Nowotny (7 December 1920 – 8 November 1944) was an Austrian-born fighter ace of the Luftwaffe in World War II.  He is credited with 258 aerial victories—that is, 258 aerial combat encounters resulting in the destruction of the enemy aircraft—in 442 combat missions.  Nowotny achieved 255 of these victories on the Eastern Front and three while flying one of the first jet fighters, the Messerschmitt Me 262, in the Defense of the Reich.  He scored most of his victories in the Focke-Wulf Fw 190, and approximately 50 in the Messerschmitt Bf 109.
Title: Hubertus von Bonin
Passage: Hubertus von Bonin (born 3 August 1911, Potsdam – 15 December 1943) was a German Second World War fighter ace who served in the "Luftwaffe".  A flying or fighter ace is a military aviator credited with shooting down five or more enemy aircraft during aerial combat.  Bonin is credited with shooting down 77 enemy aircraft.  The majority of his victories were claimed over the Eastern Front.  He also claimed four victories in Spain during the civil war.  His commands included "Geschwaderkommodore" of Jagdgeschwader 54 (JG 54—54th Fighter Wing).
Title: Jagdgeschwader 54
Passage: "Jagdgeschwader" 54 (JG 54) was a Luftwaffe fighter wing during the Second World War, which was the second highest scoring wing of all time, JG 52 being the highest.  JG 54 flew on the Eastern Front claiming over 9,600 aircraft shot down, with pilots such as Walter Nowotny, Otto Kittel, Hans-Ekkehard Bob, Max-Hellmuth Ostermann and Hannes Trautloft being termed "Experten".
Jagdgeschwader 54 Walter Nowotny