Sukhoi's civil aircraft division is concentrating on developing a composite wing for the proposed 75-seat version of its Superjet 100.
Speaking to FlightGlobal, Sukhoi Civil Aircraft president Alexander Rubtsov said the airframer is developing wing profiles for the shrunk twinjet.
But he states that a composite wing is considered the "main option" for the aircraft.
S7 Airlines is contributing to technical requirement guidance, and has tentatively committed to taking up to 75 of the type.
"Requirements from customers are very high," says Rubtsov. He says the quantity of composite used in the new aircraft is likely to be "significantly larger".
"We're at the stage of placing orders with our technology partners," adds Rubtsov. It has issued requests for proposals for the landing-gear, avionics, auxiliary power unit and other systems.
"Some systems [are drawn] from existing ones, some are new," says Rubtsov, who states that Russian suppliers could account for 50% of the aircraft.
Analysis of new materials, including composites and alloys, is being undertaken by Russian research institute VIAM. The Central Aerohydrodynamics Institute is also set to conduct flight modelling studies.
Rubtsov indicates that a 3m test section will be manufactured for stress and fatigue tests to assess the feasibility of the composite wing structure.
"We're talking with a number of airlines [on the 75-seat version]," he says. "The performance looking to be promising."
He states that United Aircraft and Sukhoi Civil Aircraft are aiming for a "unified" platform with the Irkut MC-21, such that both look "exactly the same" from the pilot's point of view – enabling easier conversion training – while the cabin interiors would feature the same design approach and level of comfort.
Bringing the two types together, he adds, will also lead to greater efficiency in sales and after-market support.
Sukhoi Civil Aircraft's newly-published annual report refers to a strategy of developing a 76- to 88-seat aircraft with a new wing but retaining the PowerJet SaM146 engine.
Rubtsov says the airframer's aim is to "significantly reduce the dry weight" of the aircraft, by 12-15%, and bring down fuel-burn and noise. The 75-seat variant would enter service around 2023.