During the Invasion of Poland, on 3 September 1939, he flew a PWS-26, three German planes attacked him.

Falkowski reduced the flight almost to the ground and using aircraft maneuverability caused that one German fighter crashed into the ground, and the other interrupted the attack and turned back, most likely due to the small amount of fuel.

[3] After the Soviet invasion of Poland he crossed the border with Romania, then he came to France where he became instructor at Polish School in Lyon–Bron Airport.

[6] During the battle, his plane was badly damaged, Falkowski had to jump with a parachute and broke his leg on landing.

During one flight over the Netherlands, on 9 March 1945, he was hit by flak, due to the failure of the aircraft, Falkowski had to save himself by jumping with a parachute once again.

In the 1960s he wrote an autobiographic book, Z wiatrem w twarz (With the wind in my face), edited in Poland in 1990.