By Bjorn Fehrm
February 7, 2018, ©. Leeham Co: The President of Sukhoi Civil AirCraft (SCAC), Alexander Rubtsov (who is also the Sales and Marketing Manager of the civil aircraft division of Russia’s United Aircraft, UAC), told Flight Global at the Singapore Air Show there has been a decision to develop a 75-seat version of Sukhoi SuperJet (SSJ).
Sukhoi and United Aircraft have studied whether to develop a larger or smaller version of the SSJ. A Russian order for 100 of the smaller model tipped the decision to the 75-seat model.
In the original Superjet plans, three versions of the aircraft were planned: 65-, 75- and 95-seat versions. Finally, the 95-seat version was realized as SSJ100/95.
Sukhoi and UAC have explored larger versions of the SSJ100/95 for some time. Up to 120-seat versions have been considered. But the competition in the 100+ seat segment has become harder.
The CSeries, with advanced engines, aerodynamics and structures, is now operational both in a 100- and 130-seat version. Within weeks, the 100-seat version of the updated Embraer E-Jet, the E-190E2, is starting service with Norwegian carrier Widerøe. The 120-seat E-195E2 follows next year.
Building a competitive larger version would call for an injection of new technologies into the SSJ, to come to the operational costs of these aircraft. In the sector below 95 seats, there is no new technology aircraft in the market until the Mitsubishi MRJ70 and Embraer E-175E2 arrives 2021.
The present competition is the Embraer E-175 and the Bombardier CRJ700 and 900. Of these, the SSJ has the better cabin comfort (Figure 2) and engines which are half a generation newer (the SAFRAN-Saturn SaM146 is 10 years younger in design than the GE CF34-8 which is used on the E-175 and CRJs).
So, a shortened version of the SSJ would have an easier market than a stretched version.
The largest market for 75-seat regional jets is the US regional jet market. Embraer delivered 79 E175 76-seaters during 2017, of which 71 went to US regional airlines and eight to KLM Cityhopper in Europe.
The SSJ100/75 would be the right size to compete in the US market. The cabin of the original SSJ100/75 was 3.5m shorter than the SSJ100/95, which Interjet has equipped with 93 seats at a generous 34-inch seat pitch.
The loss of 3.5m means the loss of four rows of five seats each, bringing the capacity down to 73 seats at a 34-inch pitch. With modern slimline seats at 30-inch pitch and some reduction of galley space not needed at 76 seats, the cabin could take a three-class 76 seat US Scope clause-compliant cabin.
Ideally, SCAC doesn’t shorten the SSJ100/75 the originally planned 3.5m but rather 3m, giving the three-class layout some more space. The shorter fuselage would lower the empty weight by about three tonnes. According to Rubtsov, SCAC is studying whether to build a new smaller wing or to apply the engines from the MRJ or E-175E2, the Pratt & Whitney GTF in its 56-inch fan version.
While this will give weight savings and lower engine fuel consumption, it will delay the versions entry into service. The present wing only has 10% lower wingloading than the E175 and the same wingloading as the MRJ70. So a new wing is questionable. New engines would give about a 10% fuel consumption saving, but the question is what their weight would mean for the present US Scope clause limit of 86,000lbm Max Take-Off Weight. Would an aircraft with upgraded engines have weight margin left for adequate range?
The real challenge for the SSJ100/75 is not the cabin, wing or engines, however. Nor is it the fuel consumption or operating costs in general. Though Interjet has been generally happy with Service and Support from SCAC (there have been reports of recent engine spare parts issues), we have no reports from the other Western operator of the Superjet, Cityjet.
It will require the experience of a number of Western SSJ operators over several years to tell whether SCAC can deliver, service and support a regional jet to the level where it can compete in the US market.