The new MC-21-500 airliner will not be a direct descendant of the import-substituted MC-21-310, according to Frequent Flyers. In their opinion, this is a completely different aircraft, which is called the MC-21 only because it is also a "21st century mainline aircraft."
The new aircraft will receive its own wing, center wing section, and engines. So, you shouldn't expect the effect of simply "stretching" the existing narrow-body MC-21s.
And here the name MC-21 may just reflect unification with other aircraft in the family: just as the Boeing 757 and 767 have many identical components and assemblies, a control system and cockpit, identical flight characteristics and procedures.
Such unification is a great advantage for operators. At the same time, the current global trends towards the growth of traffic volumes on medium-haul aircraft are such that machines with 250-300 seats will become the basis of the passenger fleet in 15-20 years.
The role of the PD-26 engine in the project, which will be built on the basis of the PD-35 gas generator, is unknown. The PD-35 itself has no application now - projects such as the Russian-Chinese CR929 aircraft or the twin-engine Il-96 have not been developed.
Earlier www1.ru reported that Russia is completing the construction of 7 new aircraft, 3 helicopters and 6 aircraft engines.