SSJ-115, SSJ-130 and plans for the future
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A possibility to make a 115 seat aircraft based on the same wing, the same engines design would be a great advantage to air carriers. As was said before SSJ-100/115 could be “squeezed” into MTOW LR-class. It means engine, wing, landing gear would be the same for a new aircraft. SSJ-100/95, SSJ-100/95LR and SSJ-100/115 would make a pretty large family. Let’s have a look on Embraer – are they scared off by requirement to add extra emergency door?

Eugeny Kovalenko: It’s possible to invest into MTOW LR version, but take-off weight will increase, and so landing speed and noise level. One should add to that an increased air consumption for (СКВ), which cannot be achieved with current engine model. The wings will need re-fit as well. In general, the scope of work is comparable to development of 130 seater from scratch, at least as it was originally conceived. Embraer has fitted E190/195 with new wings, new engine and new landing gear. As for extra emergency door – it is not a problem by itself, but because of RRJ-60 design legacy we have to equip it with air inflated escape chute.

Can it be fitted into main hull? The same way as on B767?

Eugeny Kovalenko: That’s exactly what we plan for 130 seater. But we cannot just simply shove it into the hull, one should think about it. In case of 115 seater – this is not a main reason against such modification.
User sadif: May be that’s why Dolotovsky only mentioned 115 seater and switched to 130-er, which requires new wing, new engine, new empennage. He said Sukoi designers will be more conservative than Boeing Dreamliner team on carbon composite applications. One should see how this wonder-wing will be re-shaped if needed.

Did I get it right, there is no place for 115-er in current family? Pity…

Eugeny Kovalenko: 115-er is the most controversial version. Europe AC did not welcome it because additional 15 passengers need an extra flight attendant (the 3rd one) as per EU regulations. They were interested in 130-150 seater. America kept quiet on the issue. Inauguration of ERJ-195 with 115 passenger capacity changed the situation. Do not trust market gurus and AC wish lists. As one truly said: we give you not what you want but what you need. Because of that we had pros and cons in this part of the project. Keeping in mind enormous stress of certifications we limited ourselves with empty talks…

Then project’s foes were right and originally planned family of 60-/75-/95 played a dirty trick on the project, and today 95-er does not have a chance to evolve?

Eugeny Kovalenko: Why foes? I have written that. On design stage 75-er was nominated as a base model, and that was approved by ACs. Because of that the wing was a compromise between 75-er and 95-er, luckily with some emphasis on 95-er (which terminated 60-er). In those time 100% unification of wings, engine and gear was a major objective. For soft surface runways we proposed 4 wheel gear. As for further development if we assume Embraer’s approach (new engine, new wing, and new gear) everything is feasible. Now this idea is being employed in NG project. With such approach and 115-er will be completed. But this means extra money, extra labour…

What is the legacy of 60-er? As far as I know a height of landing gear leg is less than E-190. How this problem was solved?

Eugeny Kovalenko: Because of short nose (60-er) we had to move engine closer to the wing (not the best solution to improve aerodynamics) in order to provide free access to the front cargo hatch. To decrease interference between wing and engine nacelle, the engine was lowered. But because there should be a minimum gap between engine and the ground (no one wants to knock off airstrip landing lights) we made the gear leg longer. This way we found ourselves off the required height limits for several cm. And these formalities are beyond our control. As for Embraer, its height is less for almost the same amount. I mean height of back edge of the wing at junction point, where passengers should jump off in case of emergency.

User В: Eugeny Nikolaevich, thank you for info on 115-er, it’s fascinating. If you can share anything else, I would appreciate greatly. Amount of necessary changes pushes 115-er off the “old generation” family. It’s a pity… I mean first try became a valid attempt but not a fantastic leap forward. No one had expected that design errors of 60-er at very early stages would affect the project path for so long! It’s true that small miscalculation at the beginning sometimes would result in great consequences. And situation with new engine pylons became clear at once, and the reason why the top management does not harry up with new building program in KMC. Never mind, looks like your NG will be a real sweet baby! And then all “child diseases” of the project will stay in the past. Good luck to you! (And to all of you too!)

98 passengers were evacuated in 73 seconds instead of 90 sec as required. I think there is a time reserve for 108 and 115 passengers even without additional emergency exits on the wings?

Eugeny Kovalenko: Besides time limits there is minimum required distance to the emergency exit, and with 110+ seat capacity there is a legal requirement for certain number of exits. So 115 seats setup (unlike 108-110 seats) changes the picture drastically.

Eugeny Nikolaevich! Did I get it right GSS had taken decision to evolve 130 NG into 115NG and dump current generation 115-er? And second question: what will happen to 100-95 project? (and SAM-146)

Eugeny Kovalenko: About 130NG–>115NG, yes, we think about it. But one should judge what is better: 130NG—>115NG or 130NG—>95NG. There is good saying: I should have been smart BEFORE as my wave is smart AFTER. The life proved that efficiency of family is higher if passenger capacity between models is more than 30%. This way the 115-er has a chance for production life only if its development is cheap. But development of 115-er as an offspring of 100-er with new outfit (new engine, wings etc) – is just money burn. Such investment would never pay back in full. Embraer decided not to run for 100% unification and created 2 families E170/175 and E190/195. This allows quick changes in design within each family. We followed different path and now life corrects us (see proverb above). Today we work on 103 seat model, with 30 inches space between seats. Model with 108 seats requires more air supply which is beyond current capacity of SaM-146. All these designs (103-108 seats) require minimum changes, and if there is a big order we will consider them. About skeleton chairs: they are lighter but much more expensive (made of carbon). Engine SaM-146 has good prospects for further development in models with 103-108 skeleton chairs.

Is it possible to create 115-er "old-gen" with new pylons and shortened Gear Legs? Without changing the wings? Will it cause troubles with inbalance or anything similar?

Eugeny Kovalenko: New pylons require changes in wings profile otherwise we face additional losses in aerodynamics. Shortened legs require changes in cinematics (not to drop off from the landing gear bay) and changes in wings design at least, because landing gear legs position will be changed.

Finally SSJ fans got to know that changing aircraft seat capacity is a serious work. “Bad wishers” had expressed misgivings about 115-er project feasibility, but fans shouted “Shut up! You know jack shit in SSJ design!”

Eugeny Kovalenko: Why some people want see only crap everywhere? In 737 development Boeing has changed wings, engines, not just stretched the hull. Is it a sign of dwarf mind? Our position on 115-er was expressed in yearly 2006, when a discussion sparked on the issue. The discussion stopped and then started again, and we again explained hopelessness of this idea. And this goes and goes on. New 130-er will not compete against 100-er (but that is more than possible between 100-er and 115-er). The 100-er totally fulfilled our expectations, I believe it faces long production life!

29 Jan 2019 06:44


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