Crippling sanctions over Ukraine invasion - Western governments have closed off their airspace. Planes owned by Russian firms & planes registered in Russia banned in multiple jurisdictions. The West is also on the lookout to seize leased planes operated by Russian airlines. Russia's industry partnerships have collapsed; maintenance agreements are also at risk. Aircraft manufacturers Boeing, Airbus, & Embraer have pulled out - they'll no longer sell spare parts. Some analysts say Russia may ground few aircraft & use them to ensure spare parts for the operational jets. Russia may also ensure spares & components through suppliers & partners in third countries.