Ukraine's air force is a relic of the Soviet era, with Russia equipped with far more modern and advanced aircraft.
Colonel Yuri Ignat, a Ukrainian air force spokesman, told Forces News Ukraine is "fighting with the equipment of the 70s and 80s".
Yet, Ukraine is exceeding expectations against the Russian air force, with Russia struggling tactically to quell those from Ukraine.
One reason could be the training help received by Ukraine after the Russian annexation of Crimea in 2014.
'Juice', a Ukrainian fighter pilot known by his callsign, told Forces News that Ukrainian pilots were not just taught the basics.
"From 2014, we are taught that we need to be very creative, we need to be tactically flexible," he said.
And it is that tactical flexibility – flying low, doing the unexpected – that's causing the Russians headaches.
The Ukrainian fighter aces have thrown out their flying rule book, while also knowing the Russian one inside out.
Paul Beaver, an air power historian, told Forces News there is no doubt Ukraine's air force is "on top of their game at the moment".
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"A lot of the senior people would've been trained in the Russian air force, they understand the tactics, the techniques and procedures that are used by the Russians," he said.
"My understanding of Russian tactics is it's very much by wrote, [the] way they fly is exactly as the manual says, they are not allowed to deviate.
"Ukrainians, on the other hand, are totally able to exploit every situation."
Ukraine hasn't been able to upgrade much of its air power, but it has been making the best of what it's got in terms of tactical usability.
Colonel Ignat said Ukraine "did not sit by idly" since the annexation of Crimea.
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"We understood that there could be such a scenario of events that happened, especially in the last two years. We have conducted many exercises with aviation, with anti-aircraft forces," he said.
Ukraine has been learning from the West with NATO countries, especially the UK and US, helping them better manage the aircraft they have.
But despite a great start, everyone knows daring flying, working miracles with servicing, grit and determination can only take you so far.
Ukraine has renewed its plea for either more Soviet-era jets or even F-16s to be made available to them to even up the fight.