Comparison of MC21 and A320 airplanes

1. IRKUT MC-21 analysis, Part 2
By Bjorn Fehrm
Introduction
Feb. 24, 2016, ©. Leeham Co: Two weeks ago we started our analysis of the new Russian
single aisle aircraft, United Aircraft’s Irkut MC-21. We looked at key design features and
compared these to the Airbus A320.
We also analyzed the passenger capacity where we found that the model which will start flight
testing, the MC-21-300, has a capacity between the A320 and the A321. The closest aircraft in
capacity and performance in the MC-21 lineup versus the competition would be the MC-21-200
and A320neo.
We have therefore decided to do our efficiency analysis between these variants.
Summary:
• The MC-21 has a wider fuselage than the A320. This is a positive as it allows passengers
to pass each other in the aisle of the cabin.
• The drawback of the wider fuselage is a bit higher aircraft drag.
• Coupled with a lower wing aspect ratio, the lighter MC-21 cannot open a fuel
consumption advantage over the A320neo, despite being a more modern design.
Discussion
In the initial analysis we found that the MC-21 is no copy of an existing Western aircraft. It has
chosen its own technical solutions. The fuselage has a slightly larger cross section than the A320,
something that allows a wider aisle, Figure 1.

2. Figure 1. MC-21 cross section with standard economy seating. Source: Leeham Co.
Irkut has aimed for an aisle where passengers can pass each other and squeeze past a serving
trolley. With equal seating width, the aisle will be 24 inches wide instead of the normal 19
inches.
The area of the cabin that seems less well thought out is the emergency exit concept. In the seat
capacity between 140 to 180 passengers, the preferred exit configuration has converged towards
two entry/exit door pairs front and rear, complemented with single or double overwing exits
dependent on passenger capacity.
The design drawings of the MC-21-200 and -300 show that the -200 will be a three door pair
layout with the second door pair behind the wing and that the -300 variant introduces a fourth
door pair ahead of the wing.
It might be that the certification authorities and airlines that participate in the development of the
MC-21 prefer such configurations. Emergency exit configurations which allow the higher seating
densities now being introduced for Western aircraft is something that can be introduced later in
the project.

3. We don’t have the empty weights for the MC-21 variants. We therefore let our aircraft model
estimate the likely empty weights based on aircraft dimensions and construction principles,
Figure 2.

5. Figure 2. Data and efficiency for A320neo and MC-21. Source: Leeham Co.
With the MC-21 dimensions, wetted areas/weights and the data for the Pratt & Whitney engine,
it is possible to make a first estimate of the fuel consumption for the MC-21. It consumes fuel in
the same ballpark as an A320neo. The difference of 0.8% one can ignore, the modeling is done
with estimated data for several parameters.
How come that the more modern aircraft does not have an advantage over the older A320neo?
The aircraft share the same engine, in this case, the Pratt & Whitney GTF 1100G series, so there
is no difference there. The MC-21 is somewhat lighter but the A320neo wing has a higher aspect
ratio thanks to its sharklets. Further, the larger fuselage diameter of the MC-21 results in higher
fuselage pressure drag.
With the dominant drag, which is generated by the aircraft’s wetted areas, being practically the
same, the similarity in the aircraft’s fuel consumption is not surprising.
We have not tried to go further and compare the Cash Operating Costs of the aircraft. Too little
is known about things like MC-21 maintenance concept and support network to make that
possible.
Next step
In the next article, we will take a deeper look at the Aviadvigatel PD-14. The PD-14 will be an
alternative engine to the Pratt & Whitney PW1128G for the MC-21.
The PD-14 is the first new Russian turbofan in over 30 years. A number of turbofan technologies
that previously were shared inside the Soviet Union, and especially with Ukraine, now have been
re-developed inside the Russian Federation. The PD-14 is therefore a very important project for
the rebirth of the Russian aeronautical industry.