Russia’s MC-21 has been touted for years as a new-generation passenger aircraft to compete in a market dominated by existing Western airliners. But the aircraft that first emerged from the program and the one Russia is now preparing to commission are not the same technologically. The switchover of the MC-21-300 to the import-substituted MC-21-310 has been much more than just a simple engine swap. A lot of the aircraft’s equipment, the control systems, the cockpit hardware, and even the composite materials used in the wing have changed.
The difference was especially felt on 23 September 2026, when the MC-21-300 aircraft 73054 flew with journalists on a press tour of the Irkutsk Aviation Plant from Zhukovsky to Irkutsk. During the trip, Nikolai Fonurin, lead flight-test engineer of Yakovlev, told Rossiyskaya Gazeta correspondent Ivan Pyshchekin about the aircraft, its flight-test equipment, and variations between various MC-21 models.
The comparison is striking, because the two aircraft may look generally identical on the outside, and their basic flight characteristics are likewise quite comparable. The technology base under the common airframe, however, is significantly diverse.
MC-21-300: the original configuration
The MC-21-300 is the earliest version of the aircraft, having a considerable share of foreign equipment in its design. It was powered by Pratt & Whitney PW1400G geared turbofan engines and included foreign systems and components that were already built, tested, and integrated.
The advantage of this arrangement, said Fonurin, was that most of the equipment was already tried and tested. The engineers had to integrate and connect the many systems and tune them to work together as one whole aircraft.
Thus, the MC-21-300 set the standard by which succeeding models would be measured.
However, geopolitical shifts and limitations on access to foreign components have pushed Russia to start a much more ambitious program: the replacement of imported technological content of the aircraft with indigenous alternatives.
MC-21-310: hybrid to Russian systems
The MC-21-310 initially represented a transitional stage. Fonurin described it as a sort of hybrid, using both Russian and foreign equipment.
The new import-substituted MC-21-310 is a lot different. Most of its equipment is now domestically made.
That replacement program has impacted systems throughout the aircraft. In many cases, Russian equipment has been restored and revived in terms of technology before being integrated into the MC-21, Fonurin said.
Then the engineers had to make sure the individual systems played together in a contemporary passenger airplane.
“This is the difference,” Fonurin said of the procedure. The equipment had to be incorporated into the aircraft and taught to work together efficiently.
PD-14 and Pratt & Whitney
The most obvious technological change between the MC-21-300 and the MC-21-310 is the engines.
The MC-21-300 is powered by the Pratt & Whitney PW1400G, whereas the Russian MC-21-310 is powered by the PD-14 manufactured by United Engine Corporation.
But the real airplane behavior changes a lot less than you may think from the change of engine origin.
The two engines are in the same thrust class and have virtually the same thrust characteristics, Fonurin explains. The Pratt & Whitney engine is a little more economical, but the difference is said to be rather slight.
It is unlikely that passengers will notice the difference.
A passenger boarding an MC-21-310 without being told which engine is installed would be hard-pressed to tell the difference from the Pratt & Whitney-powered aircraft, Fonurin said.
The same is true more generally of pilots. There are technical differences, such as the way the engine rotational speeds are brought up and shown, but the operating regimes have been set so that the aircraft performs in much the same way.
The airplane powered by PD-14 has also proved its capabilities to fly such routes as Zhukovsky-Irkutsk, showing that the Russian engine essentially does not change aircraft range capability on such missions.
The wing changed too
The change is more than just the powerplant.
One of the biggest improvements involves the MC-21’s composite wing.
The MC-21-300 is made of imported composite materials, while the import-substituted MC-21-310 employs Russian composites.
This was potentially one of the biggest engineering hurdles because changing the material source may have impacted the aerodynamic properties and flight performance of the airplane.
Flight testing, however, has provided a different picture.
Fonurin says the aerodynamics and flight-performance parameters of the import-substituted aircraft have already been measured. The results are said to be essentially identical with those of the preceding arrangement.
Thus, replacing the composites did not create a fundamentally different airplane in the air.
The cockpit has changed substantially
The cockpit provides perhaps the clearest visual indication of how much the MC-21 has changed.
According to honoured test pilot Andrey Voropaev, the cockpit of the MC-21-300 represents what the aircraft looked like several years ago. The imported aircraft that replaced it has updated screens, different signals, and even separate control systems.
Another example is thrust levers. MC-21-300 still has French controls, whereas the import-substituted MC-21-310 uses Russian controls.
Even the displays have changed. Both variants use Ulyanovsk-made screens; however, the newer aircraft features a later version with richer colors and less reflection, which improves reading and crew perception.
A Russian MC-21 without changing the aircraft’s character
So the importance of the MC-21-310 program is not only the fact that Russia replaced the Pratt & Whitney engine with the PD-14.
The significance of the MC-21-310 programme is therefore not simply that Russia replaced the Pratt & Whitney engine with the PD-14.
The MC-21-300 and MC-21-310 remain very closely linked aircraft, and flight testing demonstrates that their fundamental flight behavior is very similar. The changes are in the systems, equipment, cockpit, control hardware, wing materials, and powerplant.
The change is nearly imperceptible for the traveler. But for the engineers who created, tested, and integrated the airplane, it is a tremendous technological transformation.
The MC-21-300 proved that the airplane could fly with an international supply of equipment. The MC-21-310 is designed as a demonstration that the same aircraft idea can be flown using a largely Russian technology base.
Fonurin believes much of the remaining difference is due to a relatively tiny variation in fuel efficiency, not a fundamental difference in the aircraft’s flying abilities.
The next big milestone is certification and entrance into service. The aim is to finish certification and put the domestically equipped MC-21 into commercial operation following years of swapping out imported systems and testing them on the ground and in flight.
You may recognize this airplane. It may feel familiar in the way it flies. But below, the MC-21-310 is a radically different industrial achievement than the previous MC-21-300.