Russian airlines could run out of necessary parts within a matter of weeks, or fly planes without having equipment replaced as frequently as recommended to operate safely."The priority of the Russian government doesn't include consumer safety and reliability," said Charles Lichfield, the deputy director of GeoEconomics Center at the Atlantic Council, an international think tank.…

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Planes could be seized

Some of the companies leasing planes to Russian carriers are Chinese, and China has yet to impose any sanctions of its own. But it is possible that even Chinese leasing companies could feel compelled to try to take possession of the Boeing and Airbus jets they have leased to Russian airlines, Aboulafia said. That's because those Chinese companies don't want to risk any trouble buying planes from Airbus or Boeing in the future.

"These are western jets. I'm not sure how Chinese firms will treat the sanctions," he said. "And the more important thing is these jets won't be supported with parts and maintenance any longer. It's a real issue if they lose their certificates of airworthiness, which can happen if proper records aren't kept, or especially if they're cannibalized for parts."
China has already indicated it won't ship parts for those planes to Russia, according to a report on Russian news agency TASS which quoted Valery Kudinov, head of the aircraft airworthiness department at the country's Federal Air Transport Agency.

Russian President Vladimir Putin has signed a law allowing Russian airlines to keep foreign aircraft for use on domestic flights, according to state news agency TASS.

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Taking ownership of foreign aircraft will only have limited effect, though. Sanctions forbid maintenance, updates, support or the supply of spare parts for planes. Modern passenger jets require high levels of maintenance and flying them could pose risks to passengers.