party of Czechoslovak airmen including František and another future RAF ace, Karel Kuttelwascher, went to the Port of Gdynia to sail to France. On 29 July they were about to embark on a Swedish cargo steamship, the Kastelholm, when a group of Polish officials tried to persuade them to stay. Many Czechoslovaks, including Kuttelwascher, rejected the Polish offer. But František was in a group of friends that tossed a coin to decide. It landed "tails", so they stayed and joined the Polish Air Force. František and his group retrained on Polish aircraft at Dęblin airbase in Małopolska. František was made an instructor, flying obsolescent Potez 25, Breguet 19, PWS-26, RWD 8, RWD-14 Czapla and Lublin R-XIII aircraft. On 1 September 1939 Germany invaded Poland, and on the morning of 2 September a Luftwaffe air raid destroyed Dęblin airbase. František's unit evacuated its surviving aircraft to Góra Puławska, further to the southeast. On one patrol from Góra Puławska a fellow Czechoslovak pilot, Zdeněk Škavarda, was flying a Breguet 19 when he ran out of fuel, made a forced landing near German lines and was at risk of capture. František landed nearby and rescued him. František's unit retreated again, to Sosnowice Wielke airfield near Parczew. From 7 September he flew reconnaissance missions in unarmed 2-person RWD 8 and PWS-25 training aircraft, carrying an observer. On 19–20 September he attacked enemy columns near Kamionka Strumiłowa, throwing hand grenades at German troops below. On 20 September his aircraft was damaged by enemy fire from the ground so he made a forced landing near Złoczów. Two other pilots, one of whom was another Czechoslovak, landed and rescued František and his Polish observer. For his Polish service František was awarded the Virtuti Militari 5th class and received the Cross of Valour four times. On 22 September František's unit was ordered to withdraw with its remaining aircraft to Romania. The unit flew first to Ispas in Bukovina, and then via various airfields eventually to Pipera near Bucharest, where it was interned by the Romanian authorities. But many interned members of the Polish Air Force escaped. They included a group of four Czechoslovak airmen nicknamed the "Czech Cloverleaf": František, Josef Balejka, Vilém Košař (one of the pilots who had landed to rescue František after his forced landing in Poland) and Matěj Pavlovič. The four went to Constanța, whence a Romanian cargo steamship, the Dacia, took them to Beirut