One month into the war, Ukrainian officials say they have shot down around a hundred Russian jets and a further 120 helicopters, defying expectations that Moscow would quickly take control of the skies.

The exact details of how Ukraine has held back Russia’s air force are shrouded in secrecy, but is said to rely on “unique” tactics and high-risk missions. Ukraine has also benefited from a mixture of old air defence weapons, such as S-300 units, and Turkish Bayraktar TB-2 drones, as well as US-provided Stinger anti-aircraft missiles.

“Russian pilots fly more modern jets and they are capable of firing missiles at much further distances,” Andriy told CNN. “For example, in order for us to deter missiles that are fired at 80 kilometres distance, we have to approach them at 40 kilometres. If they’ve already fired a missile at us, we somehow have to have it intercepted along the way.”

Intensive training by Nato allies, notably the United States, also appears to be a factor. Coffee or Die magazine’s report said that Ukrainian pilots had frequently trained with the California Air National Guard’s air fighter wing.