Jan Ambrus  Ján Ambruš, OBE (1899–1994) was a Slovak aerobatics and fighter pilot. He flew with the French Air Force in the Battle of France and the Royal Air Force in the Battle of Britain. After the Communist takeover of Czechoslovakia he escaped and settled in the USA, where he worked as a design engineer. Ambruš was born on 9 May 1899 in Gorna Mitropolia (Горна Митрополия) in the Plevenska Oblast of northern Bulgaria. His parents belonged to a Slovak community that was invited to settle in Bulgaria after its liberation from the Ottoman Empire in 1878. In the First World War Ambruš studied at the Hungarian Ludovica Military Academy in Budapest. He graduated in 1919 after the founding of the First Czechoslovak Republic and was commissioned into the Czechoslovak Army as an officer. In 1925 Ambruš transferred to the Czechoslovak Air Force. He became a successful pilot who won awards at aerobatic competitions, including at Vincennes in 1934, and at the 1936 Summer Olympics. In 1938 he commanded the Czechoslovak Air Force Test Group in Prague and flew the Tatra T.101 on its record-breaking flight from Prague to Khartoum, Sudan. In 1939 Ambruš was made a squadron commander in Prague. He escaped the German occupation of Czechoslovakia "via" Yugoslavia to France, where he worked for the Czechoslovak government-in-exile and then fought in the Battle of France. When France capitulated to Germany Ambruš was evacuated by ship from Bordeaux to Falmouth in England. Ambruš was commissioned into the Royal Air Force Volunteer Reserve as a Pilot Officer. On 12 July 1940 he was posted No. 310 Squadron RAF at RAF Duxford in Cambridgeshire. He converted to the Hawker Hurricane Mk I fighter in August 1940 at No. 6 Operational Training Unit at RAF Sutton Bridge in Lincolnshire. He was then posted back to Duxford to the newly-formed No. 312 (Czechoslovak) Squadron RAF, and on 10 September took command as Squadron Leader. On 11 October Ambruš led a patrol of several Hurricane Mk I fighters that helped a flight from No. 611 Squadron RAF to shoot down a "Luftwaffe" of I/Kampfgruppe 606 between Prestatyn in Wales and Chester in England.