Willy Coppens Willy Omer Francois Jean Coppens ( 6 July 1892 – 21 December 1986 ) was Belgium ' s leading fighter ace and the champion " balloon buster " of World War I . Early life . Coppens was born in Watermael - Boitsfort , near Brussels and was conscripted into the army in 1912 , to serve with the " Premiere Regiment Grenadiers " . World War I . In 1914 , following the German invasion of Belgium , Coppens transferred to The Motor Machine Gun Corps . On 6 September 1915 , he signed up for flight training in the Compagnie des Aviateurs . Ultimately , due to insufficiencies in Belgian training , he took 8 weeks leave to train to fly . He and 39 other Belgians learned to fly on their own expense in Britain . He received his pilot ' s certificate on 9 December 1915 . After this training in Britain he had further training at the Farman School in Étampes , France and joined the " Sixieme Escradrille " as a " sergent 1ere class " ( Sergeant First Class ) on 8 April 1917 flying BE - 2c two seaters . Later that month , he was assigned to " Quatrieme Escadrille " to fly a Farman pusher . On 1 May , he received a Sopwith 1½ Strutter two seater and promptly flew it into his first aerial combat . In mid July , he transferred to the single seater fighter unit " 1ère Escadrille de Chasse " ( 1st Pursuit Squadron ) . He received the last remaining Nieuport 16 in the squadron ; everyone else had upgraded to Nieuport 17s . When Hanriot HD 1s were offered to the squadron , he was the only pilot to initially accept one . His enthusiasm for the aircraft type prompted other pilots to also move over to Hanriots . On 19 August Coppens was promoted to " Adjutant " . He continued his nervy but unsuccessful combat career against enemy aircraft until 17 March 1918 . On that day he carried out his first attack on German observation balloons , as an aid to a ground assault by the Belgian Army . Though handicapped by lack of incendiary ammunition he punctured two balloons , causing the observers to bail out and the balloons to collapse to the ground . Finally , on 25 April Coppens scored his first victory by downing a Rumpler two seater . On 8 May he finally found his metier , when he shot two balloons down in flames . A week later , using his usual tactics of close range fire , Coppens cut a balloon loose from its ties . It bounced up beneath him and momentarily carried his Hanriot skyward . After his aircraft fell off the balloon , he restarted its engine and flew back to base . The balloon sagged into an explosion . Later when on another attack run , he got shot at from a balloon . He parked his plane on top of the damaged balloon , shutdown his engine in order to protect its propeller , and waited until the balloon to descend to slide off the balloon and fly away . From then on , Coppens ' record was spectacular . Between April and October 1918 he was credited with destroying 34 German observation balloons and three airplanes , nearly as many victories as Belgium ' s other five aces combined . Unlike most fighter pilots of World War I , who used . 303 caliber or 7 . 92 mm guns , Coppens used a larger bore 11 mm Vickers machine gun , having upgraded his weaponry prior to June 1918 . Also in June , he was promoted to " sous lieutenant " , thus becoming an officer . His royal blue plane with its insignia of a thistle sprig wearing a top hat became so well known that the Germans went to special pains to try to kill him . On 3 August he shot down a balloon booby - trapped with explosives that when detonated from the ground narrowly missed killing him . On his last mission , 14 October , Coppens downed a balloon over Praatbos and was attacking one over Torhout when he was severely wounded by an incendiary bullet , smashing the tibia of his left leg and severing the artery . Coppens crash landed near Diksmuide and was taken to hospital , where his leg was amputated . After the war . For his wartime service he was knighted , becoming Willy Omer Francois Jean Coppens de Houthulst , for a forest in his squadron ' s operating area . He was decorated by Belgium , France , Britain , Portugal , Italy , Poland , and Serbia . His memoir , " Days on the Wing " , were published in 1931 and reissued in the 1970s as " Flying in Flanders " . Between the two World Wars Coppens was Belgian air attaché to four nations . In September 1928 , despite his disability , he set a parachute jump record by leaping from 19 , 700 feet ; this record stood for 4 years . He retired to Switzerland in 1940 , organising resistance work and marrying . In the late 1960s he returned to Belgium and lived his last five years with fellow Belgian ace Jan Olieslagers ' s only daughter until his death in 1986 . He achieved all his victories flying the Hanriot HD . 1 fighter . See also . List of World War I aces from Belgium