The MC-21-310 program holds a unique place in the annals of Russian civil aviation. Unlike the earlier post-Soviet airliners, which relied significantly on Western avionics, engines, and materials, the MC-21-310 is in the process of being certified as an almost entirely domestically produced aircraft. This transformation, prompted by the necessary substitution of imported components, drastically changed the scope, timeline, and complexity of its flight-test campaign. Consequently, the quantity of test flights and total flight hours have emerged as the most indicative measures of the program’s genuine maturity, exceeding mere chronological milestones.
Although the MC-21 family has been flying since 2017, the current certification process is not an additional stage of previous efforts but rather a new program built upon an existing airframe. The aircraft now incorporates Russian avionics, domestically manufactured composite structures, locally produced systems, and the PD-14 engine, all of which must be validated collectively as a unified, viable platform. This requirement has rendered the MC-21-310 the most extensively tested Russian passenger aircraft of the post-Soviet period.
The Scale of Flight Testing in 2025
The year 2025 represented an important phase in the certification procedure of the MC-21-310. Throughout the calendar year, four experimental aircraft engaged in the certification program completed 126 flights, totaling 418 hours and 9 minutes of flight time. These figures are noteworthy not just due to their sheer magnitude but also because of the intrinsic characteristics of the flights themselves. Each sortie was carried out within a rigorously regulated certification framework, featuring comprehensive onboard instrumentation and post-flight analysis intended to verify the performance of newly substituted domestic systems.
Unlike first demonstration flights that concentrated on fundamental airworthiness, the 2025 flights were aimed at validating performance boundaries, system redundancy, failure management, and integration performance. The four aircraft involved, with tail numbers 73051, 73054, 73055, and 73057, were designated for separate testing duties. Some flights prioritized aerodynamic performance and handling characteristics, while others emphasized avionics reliability, stability of the power supply, or environmental control performance across different altitudes and temperatures.
The total of 418 flight hours includes several individual test points gathered under real operational conditions. For certification authorities, these hours offer statistically significant evidence that systems operate predictably not only during brief validation intervals but also throughout extended cruise phases, protracted descent procedures, and repeated cycle operations that more accurately emulate airline service.
Flight Hours as an Indicator of Certification Level
In modern aircraft certification, the number of flight hours is often as significant as the total number of flights. Short flights may assess individual parameters; however, extended flights uncover system interactions and underlying issues that manifest only over an extended period. The MC-21-310’s 2025 campaign intentionally highlighted protracted mission profiles, comprising lengthy navigation flights across various regions of Russia. These flights imposed continuous demands on inertial navigation systems, communication apparatus, electrical power generation, and environmental control systems.
The prolonged flight durations further enabled engineers to monitor the PD-14 engines under steady-state cruise conditions for extended intervals. Engine performance during extended operation is essential for verifying fuel efficiency, thermodynamic stability, vibration levels, and digital control logic. Through the accumulation of hundreds of hours within a single year on the entirely import-substituted configuration, the program substantially diminished the technical uncertainties that frequently endure until the later stages of certification.
Certification Standards and Regulatory Realities
Despite a large number of flights in 2025, certification authorities have underscored that only a subset of these sorties directly contribute to formal certification credits. According to Rosaviatsia, the revised type certification for the MC-21-310 necessitates 293 specialized certification flights. As of late November 2025, only 23 of these had been formally recognized for certification of the domestic configuration.
This discrepancy is not indicative of slow progress but rather illustrates the organized framework of certification programs. Many flights are conducted for preparatory purposes, verifying fundamental safety and system performance prior to regulatory approval for the closure of formal certification milestones. In the case of the MC-21-310, this phased approach is particularly crucial, as nearly every key onboard system has been redesigned or replaced in comparison to earlier MC-21 variants.
Major Milestones in Late 2025
Several significant milestones were accomplished toward the end of 2025, fundamentally transforming the flight-test program. In October, the second entirely import-substituted MC-21-310 prototype, tail number 73057, conducted its maiden flight in Irkutsk. This event signified the shift from dependence on just one aircraft to a more resilient multi-aircraft test fleet capable of conducting concurrent testing.
In November, aircraft 73057 was transported to the Zhukovsky Flight Test Center, where formal certification trials are carried out under strict regulatory oversight. Its introduction facilitated the acceleration of the test program, allowing multiple aircraft to be concurrently assigned to various certification duties.
December saw one of the most challenging flight phases of the year: extended-range navigation testing flights between Zhukovsky and Irkutsk. These flights verified the performance of domestic inertial navigation systems and high-frequency communication equipment across intercontinental distances. The successful outcomes of these missions confirmed that the navigation suite of the MC-21-310 is capable of sustaining precision and dependability well beyond the boundaries of regional test airspace.
Finalization of Critical System Testing
By the end of 2025, multiple critical onboard systems had finalized their initial certification testing phases. These comprised the new wing mechanization system, the digital power supply architecture, the air collision avoidance system, the ground proximity warning system, the wheel brake control system, and the cabin air conditioning system. The successful completion of these tests enabled engineers to transition their focus from fundamental functionality to long-term reliability and resilience against failure.
This transition is essential because certification is not entirely dependent on systems functioning under optimal conditions. They are required to show consistent and reliable behavior during partial failures, degraded operational modes, and challenging weather conditions. The considerable flight hours accrued in 2025 established the foundation for the more rigorous evaluations planned for 2026.
The 2026 Flight-Test Campaign and Final Certification Effort
Looking forward, the MC-21-310 program advances into 2026 with the objective of conducting approximately 90 to 110 additional certification flights. These flights are anticipated to be among the most technically challenging within the overall program. Testing will primarily evaluate safety margins throughout the entire operational envelope, encompassing engine performance under extreme climatic conditions, landings in adverse weather, and comprehensive substantiation of landing gear and braking systems.
The PD-14 engines will be subject to rigorous evaluation, with tests scheduled in both chilly and hot conditions to verify their dependable performance throughout Russia’s varied climate regions. Navigation and flight control systems will undergo rigorous redundancy assessments to confirm that the aircraft can safely withstand multiple simultaneous failures without compromising control or situational awareness.
The testing of the domestic airliner is scheduled for completion by the end of 2026, enabling Rosaviatsia to grant final certification approvals in time for commercial operations.
Production Readiness and Industrial Parallelism
Although flight testing remains ongoing, progress on the industrial aspect of the MC-21 program has proceeded in parallel. The Irkutsk Aircraft Plant presently has twenty MC-21 aircraft at different phases of completion. This encompasses a backlog of fuselages and main components adequate to sustain the initial production run upon completion of certification.
The first 18 aircraft have already been contracted and are scheduled for delivery following the formal approval of certification results. This concurrent approach reduces the interval between regulatory approval and the initiation of airline services, drawing on lessons learned from previous Russian aircraft programs that experienced extended delays following certification.
Structural Testing Beyond the Flight Envelope
Flight hours alone are insufficient to verify all dimensions of an aircraft’s safety, especially when new materials are used. Approximately 40 percent of the weight of the MC-21’s structure is composed of polymer composite materials. Transitioning to domestically manufactured composites necessitated comprehensive ground testing to verify their strength and durability.
The N.E. Zhukovsky Central Aerohydrodynamic Institute carried out a comprehensive series of static experiments on domestically produced composite floor panels. These assessments replicated operational loads, impact damage, and the redistribution of long-term stresses within the fuselage. Results verified the precision of the computational models and substantiated the structural robustness of the new materials.
Certification Progress and Cost Efficiency
By the end of 2025, overall certification progress for the MC-21-310 was estimated to be approximately 70 percent. Simultaneously, the Ministry of Industry and Trade announced initiatives to streamline production expenses through the engagement of alternative suppliers and the implementation of innovative management approaches. These initiatives are intended to diminish labor intensity and ensure price stability as the program progresses from testing to full-scale production.
Conclusion: The True Significance of the Data
The 126 flights and over 418 flight hours of the MC-21-310 in 2025 are not simply statistics. They constitute one of the most comprehensive and systematic certification initiatives undertaken by Russia’s civil aviation sector in decades. Coupled with an ambitious 2026 flight schedule, comprehensive ground testing, and concurrent production planning, these figures exemplify a strategic approach aimed at delivering a mature and dependable aircraft rather than an expedited solution.
If the program advances according to schedule, the MC-21-310 will begin airline operations in 2027 not as an experimental platform, but as a completely validated aircraft supported by extensive engineering analysis and numerous meticulously conducted test flights.