Ukraine: Are arms shipments from the West making a difference?

Justin Bronk, a research fellow on airpower at the Royal United Services Institute, says there's been visual confirmation of at least 20 Russian aircraft shot down in Ukraine so far - both helicopters and jets. That's significantly fewer than claimed by Ukraine's ministry of defence, which says it has downed 48 Russian planes and 80 helicopters. Yet even the lower number shows Russia's struggled to gain supremacy in the skies.