Approximately 19% of aircraft operated by Russia’s 11 largest airlines are grounded in summer 2026, nearly double the typical 10% maintenance rate, driven by unresolved Pratt & Whitney PW1100G engine defects and sanctions blocking spare parts access. Non-state carriers face acute strain: excluding the Aeroflot group, nearly 30% of remaining major fleets are out of service, with S7 losing 33 of 104 A320neo jets and Azur Air clearing only 6 of 23 aircraft after regulator inspections. Western sanctions since 2022 cut access to manufacturers, forcing cannibalization and domestic repairs. Experts warn fleet availability will deteriorate significantly from 2027 as aircraft age and components reach end-of-service life, with Sukhoi Superjet 100s facing particular challenges.