Eager to further his education but unable to afford university fees, he was admitted as a cadet in the twelfth entry at the Polish Air Force academy in Dęblin.

[2] In the middle of a fortnight's leave prior to his first posting, he received orders to report to his unit immediately in the general mobilisation as the clouds of war were gathering and said his goodbyes to his family.

On 17 September pilots were informed at a briefing that the Soviet Army had crossed the border and was moving westwards through Poland and that, to continue the fight, they were to fly to Romania and make their way to France.

By road and rail they travelled to the port of Balchik, which was then part of Romania, avoiding internment and being provided with false papers by the Polish embassy, and they then sailed with many other airmen on the SS Patris to Marseille.

Together with several thousand other Poles he made his way to Saint-Jean-de-Luz in the Basque country and was evacuated aboard the Arandora Star to Liverpool, where his first task was to start learning English.

By August 1940 the Polish Air Force already had more than 8,000 men on its strength in Britain and eventually it consisted of sixteen fighter and bomber squadrons had been formed which were operationally subordinate to the RAF.

He described the experience as follows: "We were over twenty thousand feet with France below us when I heard on the RT [radio transmitter] that enemy aircraft were approaching, and later there were reports of attacks and warning shouts - somebody was fighting somewhere.

I thought we were moving about a bit nervously when I remembered the golden rule: never fly straight and level for any length of time - and so I too weaved behind my energetic leader, trying desperately not to collide with anybody and not to lose him.

As a staff officer he was forbidden to fly operational sorties but he had just received permission to retrain on the latest model of Spitfire when the war in Europe came to an end.

One of the aircraft he flew, Spitfire MkVB BM 597 is still flying in the colours of 317 Squadron: he was reunited with it at RAF Northolt on the occasion of the 70th anniversary of the Battle of Britain in September 2010, Kornicki then being 93.

He was posthumously promoted to the rank of Generał Brygady by the President of Poland, Andrzej Duda, in a ceremony held at the Polish Embassy in London on 3 December 2019.