Question: When did the American fighter ace whom wing man was Joseph Frank born?
Context: Frank Luke Jr. (May 19, 1897 – September 29, 1918) was an American fighter ace, ranking second among U.S. Army Air Service pilots after Captain Eddie Rickenbacker in number of aerial victories during World War I (Rickenbacker was credited with 26 victories, while Luke's official score was 18).  Frank Luke was the first airman to receive the Medal of Honor.  Luke Air Force Base, Arizona, a U.S. Air Force pilot training installation since World War II, is named in his honor. Colonel Charles Henry "Mac" MacDonald, USAF, (November 23, 1914 – March 3, 2002) was an American fighter ace.  MacDonald commanded the 475th Fighter Group for 20 months in his P-38 Lightning, ""Putt Putt Maru"" with the unit number ""100"" and becoming the third ranking fighter ace in the Pacific during World War II. This is a list of fighter aces in World War II from Germany.  A flying ace or fighter ace is a military aviator credited with shooting down five or more enemy aircraft during aerial combat.  German day and night fighter pilots claimed roughly 70,000 aerial victories during World War II, 25,000 over British or American and 45,000 over Russian flown aircraft.  103 German fighter pilots shot down more than 100 enemy aircraft for a total of roughly 15,400 aerial victories.  Roughly a further 360 pilots claimed between 40 and 100 aerial victories for round about 21,000 victories.  Another 500 fighter pilots claimed between 20 and 40 victories for a total of 15,000 victories.  It is relatively certain that 2,500 German fighter pilots attained ace status, having achieved at least 5 aerial victories.  These achievements were honored with 453 German day and "Zerstörer" (destroyer) pilots having received the Knight's Cross of the Iron Cross.  85 night fighter pilots, including 14 crew members, were awarded the Knight's Cross of the Iron Cross. Ludwig Franzisket (born 26 June 1917 in Düsseldorf – died 23 November 1988 in Münster) was a German World War II Luftwaffe fighter ace.  A flying ace or fighter ace is a military aviator credited with shooting down five or more enemy aircraft during aerial combat.  He scored all of his 43 victories against the Western Allies in over 500 combat missions whilst flying the Messerschmitt Bf 109.  He was also a recipient of the Knight's Cross of the Iron Cross.  After the war, he became a professor and director of the Westfälisches Museum für Naturkunde. 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). Edward Vernon Rickenbacker (October 8, 1890 – July 23, 1973) was an American fighter ace in World War I and Medal of Honor recipient.  With 26 aerial victories, he was America's most successful fighter ace in the war.  He was also considered to have won the most awards for valor by an American during the war according to the April 2017 VFW magazine in their special World War I edition. Wing Commander Lance Cleo "Wildcat" Wade DSO, DFC & Two Bars (1915 – 12 January 1944) was an American pilot who joined the Royal Air Force (RAF) during World War II and became a flying ace.  He remained with RAF until his death in a flying accident in 1944 in Italy.  He was described as a "distinguished American fighter ace who epitomized perhaps more than any other American airman the wartime accords between Britain and the United States." Joseph Frank "Fritz" Wehner (20 September 1895 – 18 September 1918) was an American fighter pilot and wingman to Frank Luke. A flying ace or fighter ace is a military aviator credited with shooting down five or more enemy aircraft during aerial combat.  German day and night fighter pilots claimed roughly 70,000 aerial victories during World War II, 25,000 over British or American and 45,000 over Soviet flown aircraft.  103 German fighter pilots shot down more than 100 enemy aircraft for a total of roughly 15,400 aerial victories.  Roughly a further 360 pilots claimed between 40 and 100 aerial victories for round about 21,000 victories.  Another 500 fighter pilots claimed between 20 and 40 victories for a total of 15,000 victories.  According to Obermeier, it is relatively certain, that 2,500 German fighter pilots attained ace status, having achieved at least 5 aerial victories.  453 German day and "Zerstörer" (destroyer) pilots received the Knight's Cross of the Iron Cross.  85 night fighter pilots, including 14 crew members, were awarded the Knight's Cross of the Iron Cross.  The list is sorted by the number of aerial victories claimed at night. William Yngve Anderson (June 28, 1921 – May 9, 2011) was a Swedish American fighter ace of World War II with seven official victories in Europe, flying P-51 Mustang fighters in the U.S. Army Air Forces (USAAF).  He was born in Kramfors, Sweden.
Answer: May 19, 1897