US bans maintenance and refueling of 100 planes in Russia's possession

and flying the aircraft? Is it just a war of words? I don't know.

Their jetliners have thousands of components that periodically break down and need replacement. Some of them aren’t vital, but with each successive failure there is a loss of redundancy, eventually resulting in an aircraft that isn’t safe to fly.

With no spare parts available, they can borrow parts from other airplanes, but there’s a built in limit to that. Additionally, these aircraft models depend on airspace and navigation databases loaded into their computers that are updated every 30 days or so. Without legal databases, they would be banned from flying in any other country’s airspace.