Air Ukraine has been or is being formed now by the CIA and western intelligence agencies, Ukrainian airline pilots and others are being recruited. Old C130, Caribous and other former military transports are being bought and assembled in western Europe for operations in Ukraine, many will be based in western Ukraine. They will fly at tree top level delivering arms and supplies to eastern and central Ukraine, landing on highways at night. They will be flying over friendly territory protected by stingers on the ground and drones in the air. They can insert significant forces and supplies into critical areas and can take out wounded and others. Kyiv is still not surrounded and they can land on highways close by and truck supplies into the city. They will be met by friendly forces and the whole thing is coordinated and networked via secure starlink internet connections.
Unless the Russians make significant advances soon and stabilize their lines, they are very vulnerable, only a third of the forces are combat troops and they are at the front, the rest is logistic support, soft targets for irregular forces armed from the west.