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ANALYSIS: Superjet primed for home stretch after false starts
- 19 AUGUST, 2016
- BY: STEPHEN TRIMBLE
- FARNBOROUGH
At some point in the next 12 months, Sukhoi Civil Aircraft (SCAC) will be ready to give the Superjet programme a gift rarely bestowed in the modern aviation industry: a second chance.
Sukhoi’s engineering staff have completed the preliminary design review of the SSJ100-SV, a 22-seat stretch of the original, 98-seat regional jet launched in 2000, confirms Alexander Dolotovsky, deputy to the SCAC’s chief designer. SCAC’s marketing team is now sharing the details of the stretched model’s preliminary design with potential customers. With both the Paris and Moscow air shows scheduled in 2017, Sukhoi will be ready next year to officially launch the SSJ100-SV to the commercial market.
No doubt, SCAC hopes the stretched model will enjoy more success. Over the same period when the Embraer E-Jet family has recorded more than 1,200 deliveries, SCAC has handed over to external customers only 75 SSJ100s that currently remain in service, Flight Fleets Analyzer shows. Another three SSJ100s are operated by the Sukhoi Design Bureau and 19 more are consigned to storage. Only 56 aircraft remain in the firm order backlog, with a stunning list of cancellations for 586 of the type over the past decade.
By any measure, that is an underwhelming record for a programme that Sukhoi launched in 2000 as part of a long-term plan to revive Russia’s commercial aircraft manufacturing industry. Although launched only one year after Embraer launched the E-Jet family, the Superjet entered service seven years after its Brazilian-made competitor.
That delay has only compounded SCAC’s dilemma in 2016 as the Superjet finally appears to be gaining some momentum in foreign markets, with Ireland’s CityJet now operating the type throughout western Europe. Embraer is now within two years of fielding a re-winged, re-engined and heavily updated version of the E-Jet, while the Mitsubishi Regional Jetapproaches an entry-into-service within the same timeframe.
A makeover of the Superjet was also needed to keep the type competitive in the global market. A cash injection last year by the Russian government retired the bulk of the $2.5 billion debt to SCAC’s financiers, giving the company the financial ability to respond to the new competition.
The SSJ100-SV, if launched next year, would enter a market that looks very different to that envisioned by SCAC in 2000 with the launch of the original Superjet. In some ways, the market shifts play to the Superjet’s advantages. In 2000, manufacturers generally saw a need for a product range between 65 and 90 seats. Sixteen years later, demand for 65-70-seat aircraft has evaporated, much like for the even smaller 50-seat jets. The 75-seat category still exists, mainly to support the US market, which has pilot union agreements that artificially limit the size of the regional jet fleet. Globally, demand has focused on the market above 80 seats, ranging up to 120 seats.
“There are different marketing assessments made by different marketing groups. Our marketing team, I think, is most conservative of them all and they expect more than 3,500 or 3,600 airplanes through 2032. That’s the total amount of market for the segment of 90-120-seat airplanes,” Dolotovsky says. “We expect we will be able to catch a reasonable amount from that market to support our production line.”
The competition does not intend to make that easy. Embraer is dramatically improving the E-Jet E2 family, with Pratt & Whitney geared turbofan engines, a higher-aspect-ratio wing, full fly-by-wire flight controls, a new actuation system for the control surfaces, and a longer fuselage to accommodate more seats for the E195-E2.
The Superjet is already equipped with a full fly-by-wire control system and a high-aspect-ratio wing. Although the company has more financial leverage than a year ago, SCAC has chosen to keep the design of the stretched model as common as possible with the original Superjet, Dolotovsky says. That philosophy should minimise training and maintenance costs for operators of the original version, but it also imposes some limitations.
In particular, the Superjet engine – the PowerJet SaM-146 – is not being replaced or augmented with more thrust. Instead, SCAC is adapting the power management system to provide more thrust for the stretched model on take-off, Dolotovsky says. Although the stretched model will be longer and therefore heavier, he insists the power management system changes will result in no performance penalty even during high-altitude and high-temperature take-offs.
SCAC also accepted other limits on changes to maximise commonality with the original model. The stretched version will use the same fly-by-wire system with control surface actuators, he says. Moreover, the existing, double-braced landing gear is strong enough to support the additional weight of the stretched version.
The most important change of a stretched version is a longer fuselage. In many stretch models, the manufacturer adds two “plugs” to the fuselage, one located forward of the leading edge of the wing and the second placed immediately behind the trailing edge. Instead, SCAC has chosen a different course for the SSJ100-SV. This stretch model will incorporate a redesigned and lengthened mid-fuselage section that accommodates up to five more rows of seats, Dolotovsky says.
The fuselage extension will not require SCAC to increase the size of the horizontal stabilizer, he says. The longer fuselage itself augments the moment arm of the empennage control surfaces, increasing their authority without needing to increase their size.
The original wing, however, will not survive the stretch project intact. The claimed 10:1 aspect ratio on the existing Superjet’s wing is one of SCAC’s proudest achievements, but it will not be enough to support the added weight of the longer fuselage. So SCAC is increasing the wing area of the stretched version to maintain the landing speed of the existing Superjet, Dolotovsky says. The aspect ratio of the wing also increasingly slightly to improve lifting efficiency in the absence of additional thrust from the engines.
Finally, SCAC is also incorporating a set of raked winglets to the original SSJ100 next year. The same design will be made available for the stretched version, as well as offered as a retrofit upgrade for the existing fleet, Dolotovsky says.
That package of changes is intended to make the SSJ100-SV competitive with the slightly larger E195-E2, but not in a classic comparison of fuel efficiency and trip cost. Instead, SCAC emphasises the Superjet programme’s advantages in other cost areas, such as lower acquisition and maintenance cost of the airframe and engines. In Sukhoi’s view, the five-abreast passenger cabin of the Superjet also creates “unbeatable” comfort, Dolotovsky says.
By stretching the Superjet now, SCAC also has the opportunity to re-set the supply chain for the regional jet programme. The Superjet was launched in an era when Sukhoi publicly embraced partnership with Western aircraft systems suppliers. Since 2014, however, Russian government officials have imposed an import substitution regime that so far has largely bypassed the aviation industry.
Interestingly, SCAC’s industry policy has not changed. In fact, the company prefers to keep the Superjet’s list of Western suppliers as intact as possible, as part of the goal to maximise commonality between the original and stretched variants.
“We don’t consider any changes or any tenders to change our suppliers for already existing systems,” Dolotovsky says. “We’ve not seen a need about that. We’re happy with our suppliers now.”
Dolotovsky also points out that suppliers at the component level are managed by the Superjet’s mostly Western-sourced, tier-one suppliers. Those tier-ones can choose to replace component manufacturers with local sources, or take advantage of Russia’s plunging labour costs by moving final assembly of major systems.