- Alexander Viktorovich, at the start of Sukhoi Superjet 100 project it was planned that the jet must outmatch its rivals. However, it is still not evident. What are you going to do to gain advantage over Embraer 190?

 - We already have the advantage.

 - What exactly do you mean?

First of all, I’m talking about fuel efficiency. We decided to play to our strength – aerodynamic design. In addition, Russia has vast expertise in development of FCS control laws (Flight Control System). At that we needed this aircraft to have an edge over the existing or advanced aircraft, in particular, Embraer 190. And our aircraft really has the edge in terms of fuselage diameter, which granted the new standard of comfort in under 100-seat market.

The fuselage diameter increase provides more space for passengers and makes the jet’s comfort level comparable to narrow-body single-aisle airliners; however we had to pay the price for this improvement. Fuselage diameter increase always leads to the aircraft performance penalty. It is the price you have to pay for gaining the advantage, so we had to design a wing able to compensate the fuselage diameter increase. In fact our aircraft is a “wide-body” liner in its class.

Comparison of the appearance of Sukhoi Superjet 100 and Embraer 190 shows the difference: first of all, in terms of fuselage diameter, and second, - in terms of wing aspect ratio. Our jet has a very high wing aspect ratio – 9.9. Only Boeing 787 has higher wing aspect ratio. Such wing improves aerodynamics not only in cruise mode, but also during takeoff and landing, because the increase of wing aspect ratio improves lift-to-drag ratio and lift performance.

- SCAC is adopting practices of foreign airframers. Whose experience was the most valuable for the project?

- It is well known that at the start of the project we have been cooperating with Boeing, who acted as a consultant for us. Boeing’s experts told us: «Guys, your key task is to enter this market. It is hard and only a few companies have managed to do it, because the “entry fee” is rather high. Because this is a kind of an elite club of civil aircraft manufacturers and it has its own monopoly».

But we relied not only on experience of foreign airframers, but also on expertise of our aircraft industry. It should be noted that despite SCAC being a subsidiary of Sukhoi Holding Company, most part of the specialists involved in the development of SSJ 100 came from other companies. These people brought the best practices of Russian aircraft industry to Sukhoi Superjet 100 project. Employees from design bureaus of Tupolev, Ilyushin, Mikoyan (RAC MiG), Yakovlev, Myasishchev and even Lozino-Lozinsky (NPO Molniya) are working here. Moreover, hundreds of young professionals have been trained over the last years.

Taking into account the competitive environment we understood that if we develop “common aircraft”, we will have to follow the steps of Airbus (editor.: A300), which completed its first project just to establish an international cooperation and lay a foundation for development of profitable commercial projects. However, Airbus was supported by the international consortium having almost unlimited financial resources. We did not have any of the abovementioned advantages. That is why we couldn’t afford to develop a non-competitive aircraft.

Unlike our rivals, SCAC had an ace in the hole in the form of vast experience in the area of design of optimal transonic aerodynamic configurations in cooperation with TsAGI. Over the last 40 years TsAGI has been developing a technology of 3D optimization of airfoils intended for transonic flight. It is a unique technology and no other organization has mastered it yet. Even Boeing has not solved this problem in such formulation. We decided to use TsAGI’s expertise and worked closely with the institute right from the start of our project.

As a result we designed the wing with high aspect ratio having a very good speed performance. It was adjusted for cruise speed of 0,78-0,8 Mach. In fact this is the optimum, because we have the lowest fuel consumption per kilometer at these flight speeds.

- We often hear SCAC talking about SSJ100 having an advantage over Embraer 190. The company tells us about different percentage, but no one has ever explained the nature of this advantage.

First of all this refers to aerodynamics. The optimal Mach for Embraer is 0,76-0,77. Not a big difference if we consider the fuel consumption per kilometer. The difference becomes significant in terms of fuel consumption when we fly at the same speed. Both SSJ100 and Embraer 190 are the jets intended for common routes instead of highly specialized regional ones. And the most popular jets on these common routes are Boeing 737 and Airbus A320, which generally fly at the speed of 0,78 Mach.

And when Embraer 190 flies at 10000 meters or higher, it has to fly at non-optimal speed together with Boeing 737s and Airbus A320s. That is why its fuel consumption increases; you may see its characteristics in the Airport Planning Manual. If we see the decrease of range then we may talk about increase of fuel consumption by at least 3% (while the Mach number increases only by 0.01 – 0.02).

Second, besides high wing aspect ratio and moderate wing taper ratio we have also decreased the wing area as compared to our rival. Moreover, Sukhoi Superjet 100’s wing loading is higher as compared to Embraer (+14%). It allows us to implement the maximum lift-to-drag ratio.

Let me explain, lift-to-drag ratio increases in parallel with the lift force coefficient. For example, your aircraft has a wing optimized for lift force coefficient Су=0,5-0,55. In order to keep these values during flight at a given altitude and cruise speed you need a wing with a specific area. The wing area is chosen on the basis of two criteria: cruise flight and takeoff/landing. It looks like Embraer has chosen takeoff/landing criteria; that is why its jet has higher wing area as compared to Sukhoi Superjet 100. As a result after changing the flight level from FL350 to FL330 the fuel consumption of Embraer 190 increases by 7%. As for our jet – the fuel consumption increases by less than 3%. The combination of these factors, wing planform and better profiling provide better speed performance and advantage in terms of fuel efficiency over Embraer 190 on a real 500 miles route (-7%). And 7% is as much as the difference between current and previous generation of aircraft. The operators choose one aircraft over another when the difference in fuel efficiency between them is 5% or more. This is what refers to the fuel efficiency advantage.

- Then why when we ask about the advantages Superjet has over Embraer, we hear about overhead compartments and fuselage width instead of all the above-mentioned factors?

- Because the jet is made for passengers.

- The aircraft is also made for operators, who use them to earn money. First of all you must convince an airline to purchase the aircraft and only then the passengers will have a chance to benefit from its comfort. And you should speak about other factors instead of overhead compartments in order to convince a carrier.

- You have to use all the possible reasons to convince the carrier. However, strange as it may seem, first of all an airline looks at dispatch reliability, maintenance costs, etc. – and we have paid special attention to these areas in the network of our project. But it is not enough. In order to meet both necessary and sufficient conditions and sell the aircraft you must have an edge. I must admit that this jet has been developed for both Russian and global markets. That is why marketing research was focused on global market. Of course we took the Russian market into account too, that is why the jet may be operated at a temperature of -55 Celsius and higher, despite the fact that we had to make great efforts to achieve this milestone. It is not that easy, for example, B737-700 cannot be operated at such temperature.

And what is important for a carrier? Every airline is also a service provider. It must offer something special to its passengers to make them choose this specific airline.

- I think it is a matter of opinion. I am not sure that major part of passengers inquires about an aircraft model, while choosing a flight. First of all they choose a carrier and a ticket price. For example, if they choose Aeroflot, they are confident that the carrier will offer them a new state-of-the-art aircraft and a guaranteed quality of service regardless of whether it is a domestic or an international flight. And all the aircraft in a carrier’s fleet offer almost the same comfort meeting the requirements based on the specific airline’s business model and service standards. 

 - Exactly, an aircraft must fit into an airline’s fleet. At present most of the carriers operate Boeing 737 and Airbus A320 jets. These are the most popular narrow-body aircraft in the world. For an airline to provide nearly the same comfort, a regional aircraft must have a spacious fuselage, wide seats and spacious overhead compartments.

I’ve seen many times when people take their bags out of A320’s overhead compartments and then they board Embraer 190 and have to put their bag on their knees, because the overhead compartment is too small for it. Nevertheless, Embraer says that any hand-luggage, that fits the standard frame, will fit the overhead compartment of E190. It is not true and it leaves a bad taste in the mouth of the passengers.

Moreover, I must admit that Embraer has used this feature in its advertising campaign and managed to drive CRJ out of the market. Previously CRJ got lucky: there were no other regional jets and the carriers were interested in such vehicles. They had a business jet having a necessary size and capacity so they derived a regional jet from it and entered the market. Since there were no other jets in this segment the passengers had to take flights onboard CRJ. They had to put up with necessity to place their baggage in the baggage compartment and a small seat pitch, but at the same time they travelled fast. And suddenly a new jet having more spacious cabin and overhead compartments appeared, so they chose Embraer. Airlines began to abandon CRJ. We hope to use the same scheme in order to put competitive pressure on Embraer: passengers will come onboard and say: «Yes, this jet is more comfortable. Next time I’ll fly with this airline».

- Ok, let’s get back to technical advantages SSJ has over its rivals. Aerodynamics, comfort…what else can we add to this list?  

- We should give credit to our engine. The fact is that the engine has been developed especially for our aircraft. The performance specification for the engine has been elaborated by SCAC; I was taking part in this process in 2003-2005. The engine has been optimized in terms of both cruise and takeoff thrust. In other words: the engine’s specific fuel consumption (SFC) curve has a flat optimum at the bottom. It is very important to have a propulsion performance, which provides the lowest SFC during cruise flight. It the engine is oversized, the cruise flight zone will move to lower thrusts with higher SFC. If the engine is undersized – this zone will move to higher thrust and the SFC will increase.

CF34-10 engine installed on Embraer 190 has higher thrust as compared to SaM146. As a consequence it cannot have optimal fuel consumption on the given altitudes. I must admit that the jet developed by Embraer is good, but it may have been even better if they had optimized it accurately just like we and our partners from PowerJet had.

I remind you that the engine delivered by PowerJet was developed by Russia and France (the intellectual property is shared almost fifty-fifty between Snecma and NPO Saturn). They have implemented a number of technologies allowing us to have the lower cruise SFC as compared to CF34. For example, an active clearance control system – the technology developed for CFM56 engine. The same system was used during development of our engine; it grants lower fuel consumption as compared to engines not having this system.

SaM146 is fitted with wide-chord fan blades and a low-speed fan providing great characteristics in terms of foreign object damage susceptibility, moreover, the fan provides high efficiency at different speeds. Our engine has lower bypass ratio as compared to CF34-10, but this is our advantage, because such engine has better characteristics at different Mach numbers. For example, it has the advantage in terms of climb performance. Despite the fact that Sukhoi Superjet 100’s engine has lower thrust, it climbs   to the cruise flight level faster than Embraer 190. That’s because our engine has a more flat thrust-speed curve as compared to CF34-10. All these factors help decrease the fuel consumption.

Thanks to multi-objective optimization of our layout together with the powerplant we have reached a peak value of almost every parameter related to flight performance. In addition, these peaks are flat, thus, deviation from optimum performance will not cause significant increase of fuel consumption.

- Do I understand correctly that you’re talking about the jet’s potential, which has not been realized in operation yet? Experts believe that SSJ100 matches Embraer 190 in terms of operating performance, or at least, in terms of fuel consumption.

 - No, we have lower fuel consumption. We already have the 7% advantage and this fact is confirmed by aircraft operational data obtained, for instance, from Aeroflot.

- Is there any potential for further improvement of the aircraft performance?

- Yes, there is. We have launched a performance improvement program, which will take several years. The program includes improvement of the jet’s aerodynamics by means of decreasing a parasitic drag.

Parasitic drag consists primarily of pressure drag of the jet’s components not contributing to the lift. These are doors, steps, access doors, gaps, etc. The smaller an aircraft, the more this factor affects parasitic drag and we have to take it into account. In fact we have already reached acceptable level of this parameter: for such a small aircraft this coefficient does not exceed 10%. It is a very good result. Generally this parameter reaches about 15% for aircraft of such size.

For MiG-29 or Su-27 fighter the parasitic drag may reach 35% of the total drag. If we consider a larger aircraft, for example, Il-96 (the lowest parasitic drag among Russian-produced aircraft) has a parasitic drag of 5%. Large Boeing (777 and 767) and Airbus (330 and 340) aircraft demonstrate the same level of this parameter. Thus, our jet is somewhere in the middle.

However, we must understand that it is a double-edged sword: you may have an absolutely smooth aerodynamic surface, but it will dramatically increase the self-cost.

We are also considering installation of Sharklet of Whitcomb winglets. The advanced methods of 3D optimization allow using winglets at a brand new level. I mean if we compare winglets of Tu-204 or Il-96 with the ones we have (wind-tunnel data) you may see that the efficiency increased by 30%. I am talking about improving fuel efficiency by means of installing the winglets.

- There are different opinions about the efficiency of winglets. According to your assessment, how much will it improve the aircraft performance and fuel efficiency?

- As for winglets, which are being considered, we expect them to decrease fuel consumption by 3%. It is a significant decrease. Moreover, we have obtained a very interesting synergistic effect in accordance with the existing wind-tunnel data. We will also dramatically improve takeoff performance under conditions of high altitude and high temperature. Usually an aircraft is limited in terms of climb performance under such conditions; so we expect the increase of maximum takeoff weight by several tons. It is a very interesting result.

- You have mentioned Aeroflot. Can you announce the fuel consumption data obtained from this carrier?

- No I can’t because this is Aeroflot’s commercial secret. But I can tell you that Aeroflot is carrying out route planning using SITA system. The SITA uses data provided by the jet’s manufacturer - SCAC. The calculations made by Aeroflot show that the jet meets the claimed parameters in terms of fuel consumption. If the fuel consumption would have been 5, 10 or 15% higher (as some people believe) than we must have corrected the SITA data immediately, because route planning is a serious process controlled by the Federal Air Transport Agency.

- The engine and wing have been optimized. Isn’t it too high of a price for impossibility of developing an aircraft family?

- And who says we can’t develop an aircraft family? I remind you that initial family was supposed to have a very small size. The project was named RRJ60/75/95. In 2003 the first set of rated performance data included six books. We kept on elaborating them until 2005. Rated performance set includes data related to aircraft performance, handed over to carriers in order to analyze a potential route network. Until 2005 we have been elaborating all the six sets (60B/LR, 75B/LR, 95B/LR).

At that time aircraft seating between 60 and 95 passengers seemed attractive. In those days people were ready to pay just for possibility to perform flights. The price of a barrel of oil was lower. In mid 2000s its price increased 4 times and people started to count their money so we understood that 60-seat segment has no more room for jets – only turboprops.

After that the 75-seater became the flagship of our family. However, we have been choosing a model to promote. I might be wrong but I think that the decision to put the 75-seater program on hold and move to higher capacity was taken in 2005.

And this fact does not mean that we cannot move to even higher capacity. We can. The fuselage diameter chosen for RRJ is optimal for aircraft seating up to 130 passengers. The jet’s platform in terms of systems will remain in operation for at least 20 years. And I must admit that SSJ100 is the first aircraft manufactured in Russia to have an IMA-based avionics (integrated modular avionics). Using this platform we may develop the larger aircraft within a short time and expand our aircraft family.

Strange as it may seem, even SaM146 engines have enough thrust for an aircraft seating 115-120 passengers. However, they are not suitable for a 130-seater.

- But the possibility of developing the 130-seater has been discussed for several years. If my memory serves me right I heard about this aircraft for the first time in 2009. Don’t you think that “excessive” 2,5 tons of the aircraft’s empty weight are the reason why it is impossible to fit the 130-seater with SaM146 engines?

- You’re wrong. Let’s take a look at the existing design. The increase of aircraft’s empty weight was the price we had to pay for entering the global market. When a new airframer enters the market, he must announce an aircraft performance that makes everyone say “Wow”. Of course we knew the actual aircraft’s empty weight right from the start during its development. We would have been unable to design the wing, choose the engines and carry out strength tests (which must be completed prior to assembly of the first prototype) without knowing the empty weight. It should be noted that the increase of aircraft’s empty weight against the initially claimed value did not make any significant impact on the jet’s most important parameters – range and fuel efficiency.

By the way, our jet has great weight characteristics. The aircraft having the same passenger capacity as Embraer 190, larger fuselage diameter and the same design service life still has lower weight. Embraer190 is heavier by 650 kg. The empty weight of Embraer190 is over 28 tons, while the weight of Sukhoi Superjet 100 is slightly above 27 tons. At that the jet meets all the requirements in terms of strength.

And now let’s take a look at the existing platform. When you separate from the platform no one would believe that an aircraft with higher passenger capacity (+20%) has the same weight.

We have a durable landing gear, excellent double-strut gear legs, a real work of art. They are able to endure the roughest landing without any damage. Of course double-strut landing gear is heavier than a single-strut one. But when a single-strut landing gear is mounted on the aircraft it turns out that the hinge fittings need to be reinforced. As it turned out the single-strut landing gear together with reinforced hinge fittings are heavier than double-strut landing gear. Our landing gear has lower weight as compared to the single-strut one installed on Embraer 190.

- Is this landing gear suitable for 130-seat version of Superjet?

- No, it is not suitable for the 130-seater, but it is suitable for an aircraft seating 115-120 passengers.

- We are saying that NG version will be developed in future. What exactly is SSJ NG?

- NG is a 130-seater. However, this program has been put on hold until 2016. But no one said that we can’t develop an aircraft seating 115-120 passengers. It is a very good rival for Embraer E2, which is being developed. Taking into account the scope of modifications to be carried out by Embraer, the jet’s price will increase significantly. And even if we use SaM146 engine instead of advanced GTF, the difference in terms of self-cost will override the benefits of higher fuel efficiency.

- Will the market situation be so optimistic? Some people believe that the glass is half empty; the others believe that it is half-full.

- This is not optimism, it is reality. I understand that it is hard to believe that a new company established from the ground up, which has nothing in common with traditional civil aircraft companies, has managed to develop a good aircraft. But as I said before SCAC has been established on the basis of the whole aircraft industry.

Active staff recruitment was being carried out by SCAC in 2003. At first we had only a small group of enthusiasts, but then the program was launched and the number of employees started to increase. Honestly speaking, when I decided to join the company I just wanted to work, because I was tired of idleness and despair, which prevailed in RAC MiG in those days. And when I came to SCAC I saw a group of people with a twinkle in the eyes. And I joined them. This is the only reason why we have managed to develop the aircraft from scratch in 5 years. This is the pace of a well-established company, not a newly-established one.

- No, it is not hard to believe, because we are talking about plans and obtained results instead of an abstract belief. You said discontentedly that NG program has been put on hold until 2016, but I think it is a wise move. You have to design a new wing and it makes sense to wait until the composite wing production is launched and all the necessary technologies are mastered. Do you agree with me?

- It is clear that composites are very popular and they are believed to be an essential part of an advanced aircraft. However, after thorough analysis we may see that both metal and composite wings have their own advantages and disadvantages.

For example, Mitsubishi, who planned to use a composite wing in the network of MRJ project, (the company manufactures composite wings for Boeing 787 Dreamliner) decided to opt for metal components in most cases. That is because the aircraft’s size is very important factor in terms of effect caused by new materials.

Bird strike is one of the simulation cases. The thickness of Boeing 787’s body panel is higher as compared to panels of an aircraft of the same size as SSJ (provided that panels have the same strength). Boeing 787’s panel will endure the bird strike. However, the bird will penetrate through a thinner panel. And if we make a panel able to endure the bird strike, than the composite wing will be heavier than the metal one. Everything’s relative.

I think that our jet is technologically perfect. Why do you think Komsomolsk-on-Amur Aviation Plant keeps increasing its output?

- You’re talking about high production rates?

- Of course. After a total collapse and suspension of production the increase of the plant’s annual output by 100% is a very high rate. I can tell you that when the plant has competed the assembly of the first flight test aircraft (MSN 95001), very experienced employees of Sukhoi design bureau have inspected it and said that it is the most “flat” aircraft they’ve ever seen. That’s the result of implementation of new technologies. And every next jet gets better. The quality is improving.

- I would hardly say that this jet was “flat”.

- “Flat” does not mean that its surfaces are smooth. We say that the aircraft is flat based on symmetry of assembly and installation of its major components, for example, wings. The jet’s wingspan is 27.8 meters and you need to assemble the wing without any gaps accurate up to 0.1 degree; can you imagine the assembly and manufacturing accuracy?

- There is one more popular question: whether Superjet 100 is a regional or a short-medium haul aircraft? Judging by market orientation, this is a segment of Airbus A320 and Boeing 737; the similar jet having a smaller size.

- In fact – yes. Sukhoi Superjet 100 offers comfort and functionality similar to А320 and В737, however, it is smaller and has a shorter range. At present the emphasis moved due to world crisis. A hub system worked well: the regional aircraft transported passengers to the hub and the short-medium liners and long-haul aircraft transported them to their destinations. At present Boeing offers a point-to-point system allowing the carriers to optimize their fleet in accordance with a given passenger traffic. No one has abandoned the hubs yet, but the new market opportunities are now available.

I must admit that our jet may perform any of the abovementioned tasks thanks to its fuselage size. The airliner may act as a regional aircraft, because it has good fuel efficiency, good takeoff and landing performance, it fits the hub & spoke scheme providing a carrier with additional advantages in the area of comfort. The passengers will not feel the difference after moving from one aircraft to another. But the liner is also suitable for point-to-point scheme. It is not hard to spend 3 hours onboard SSJ 100. It offers low noise level inside the cabin, spacious seats, comfortable lavatory and a galley with hot meals. Our jet provides the passengers with comfort similar to single-aisle narrow-body jets. The vehicle’s range covers Europe and European part of Russia. Even basic version of SSJ is capable of performing flights from Moscow to any city of Europe and European part of Russia. The LR (Long Range) version offers a range of 4000 km and allows performing flights, for example, from Moscow to Novosibirsk (taking into account the head wind) or from Moscow to Cairo and nearby resorts.

The jet is able to carry passengers and their luggage for 1.5 – 2 thousand miles and offers the same level of comfort as Airbus A320 or Boeing 737. Such capabilities add   operation flexibility, which is a big advantage of our airliner over Embraer 190.

- And finally, could you to name more technical advantages of Superjet, besides the abovementioned ones?

- This jet has been developed from scratch by a new team, that’s why the boldest ideas, never used by the world-famous airframers for fear of challenging stereotypes in the area of piloting and maintenance, have been implemented during SSJ’s development.

For example, we have a great fuselage design. In terms of manufacturing technologies this is one of the world’s most producible airframes. The number of hours required for manufacturing a fuselage section is minimal. Fuselage sections were the first type of components to be manufactured by the Komsomolsk-on-Amur plant. It is a complex part, almost as complex as the wing, but we have started its production within a short time and achieved a good quality in terms of precision.

SSJ100 is fitted with one-piece machined joint-free upper and lower wing panels. Only the most advanced aircraft are fitted with similar panels. At present there is no other advanced technology in this area. Once again, I am talking about the manufacturing technology.

Speaking about the jet’s systems, all of them have been developed or modified especially for this airliner using the advanced components; they meet the most stringent requirements in terms of flight safety and environmental protection.

I would like to admit that the requirements have been elaborated by SCAC. Intellectual property created in the network of this project belongs to Russia not only in terms of wing and fuselage geometry. For example, we have three closed-type hydraulic systems; only few other jets are fitted with such systems.

We have the most advanced ice protection system in the world. We have met the requirements set by EASA after a crash of Airbus A330 in the Atlantic.

The glasses installed in the jet’s cockpit provide maximum visual angle and have the largest area in the world among civil aircraft. It is very important for regional jets, because they are operated from different airfields and sometimes they have to perform flights under poor-visibility conditions. The glass is heated, but at the same time it is absolutely transparent. This technology has been developed especially for our jet and at present Sully-Gobaine (France) is the only manufacturer in the world to supply the heated glass having such area and such a high level of transparency.

SSJ100 is fitted with an avionics suite based on technologies used during development of А380 and А400. This is the most advanced equipment and it will stay relevant for at least 10 years.

The aircraft control system has been developed almost from scratch especially for SSJ. It is the only regional aircraft in the world to have a fly-by-wire control system without mechanical redundancy and with a full set of functions in the area of flight envelope protection. Only A380 and A400 aircraft have systems of the same level. Have you seen the dimensions of our control system’s computing equipment? It is located in two small crates having a size similar to a good graphic station.

Flight control system architecture of Sukhoi Superjet 100 is divided into two levels: the first level assures a high level of reliability and provides flight without mechanical redundancy; the second one – provides the full set of algorithms for obtaining flying qualities. The computing equipment implements the control laws in full. This jet flies like asimulator. It is very easy to pilot the liner and it prevents the pilots from making mistakes that may cause an in-flight emergency or a crash. It is a unique architecture; no one has it – and this is a part of our standard specification.

Let’s talk about air conditioning system. There was much ado about it earlier. Have you ever performed flight onboard another Russian-produced advanced aircraft? Did you feel a temperature gradient, when you entered the cabin? It is colder in the rear and front parts of the cabin. It is a known defect, but no one has fixed it yet. Our passengers do not complain about temperature gradient despite the fact that it is harder to cool and heat such a small liner, especially when it is divided into two (or three) temperature control zones. The smaller an airframe, the more notable the gradients are.

The pressure control system is fully automated. It provides a constant differential pressure: regardless of the jet’s vertical speed your ears won’t pop during climbing or descending. And if we consider old Boeing aircraft, there are some special limitations in the Pilot’s Operating Handbook related to vertical speed during descending (they are connected with passenger comfort). The automatic equipment of SSJ100 solves these problems.

- That’s good, but the aircraft still has some “teething problems” …

- Yes, right now we have to deal with so-called “teething problems”...And it is natural. All the liners, even the ones developed by world-famous companies, have such problems? Have you ever read about the start of Tu-154 operation (written by Ershov)? This jet became the “workhorse” of Soviet civil aviation. «…A beautiful liner surrounded by technical specialists was nicknamed the “Aurora” – three smokestacks and it never moved …»? A new aircraft is not only new technical solutions, but also new aspects, and the operators need to get used to them.