Sukhoi Superjet: Great Expectations

Sukhoi Superjet in flight

By Vladimir Karnozov

In the year since type certification was gained, the Sukhoi Superjet 100 (SSJ100) has demonstrated mixed results.

As of mid-January 2012, the five SSJ100s delivered to Armavia and Aeroflot in 2011 amassed 1,940 flights and 3,650 flight hours. Of these, Aeroflot's four airframes were responsible for 1,418 commercial flights and 2,381 flight hours. The best monthly turnaround so far was demonstrated in September by RA89002, with 151 flights and 231.5 flight hours. By comparison, another modern Russian-built jet - the 68-seat Antonov An-148 in Rossiya's fleet - recorded a fleet-average monthly utilisation of 300 flight hours per aircraft, and 400 flight hours for the best airframe.

But Superjet's performance has been improving. In its first calendar month of operations following delivery on 9 June 2011, Aeroflot's first Superjet was flight-ready for 17 days, during which it logged 101 flight hours in 60 flights. The aircraft was grounded for 12 days in July following an in-flight malfunction of the air conditioning system. After operations resumed, the same airframe has routinely performed up to four round trips daily.

Initially, SSJ100s were flown mostly on Moscow-St Petersburg services. However, a series of technical issues and misfortunes prompted Aeroflot to move the new type from this high-gain route to less significant services. In December it began flying SSJ100s to Oslo and Budapest, as well as 11 domestic destinations served from Moscow-Sheremetievo airport.

As of January, 40 Aeroflot pilots, 24 attendants and 100 technicians had qualified on the type. While the technicians and maintenance workers found the SSJ100 a bit of a headache, the pilots have largely been impressed by the new Sukhoi.

Aeroflot SSJ100 detachment commander Eugeny Voronin praises the aircraft as easy to handle, with a highly ergonomic cockpit and good flight envelope protection system: "[This is] an efficient and reliable airplane with a big future," he says.

Commercial director Andrei Kalmykov adds: "We understand perfectly well that the airplane is in the initial stage of operations, and so we take special care about it."

In his public statement on Superjet, Aeroflot general director Vitaly Saveliev said: "These ­airplanes are becoming an important element in our fleet, helping us stay the most modern and technically advanced fleet in the whole of Europe. We use the SSJ100 primarily on domestic services, in a hope this type would help us maintain our leadership in that market sector. The SSJ100 demonstrates a large potential on our domestic services."

However, Saveliev's letter to the Russian government gave a more nuanced view of the SSJ100's strengths and weaknesses, noting that - pending resolution of some issues discovered during operational trials - Aeroflot was ready to firm up a follow-on order for 10 ­aircraft, in addition to the 30 already ordered, and would award Sukhoi with some additional contracts.

So far the PowerJet SaM146 ­motor has been Superjet's weakest link, with at least four known cases of non-scheduled engine removals.

At the MAKS 2011 air show, PowerJet chief executive Jacques Desclaux acknowledged the SaM146 had suffered surges on deliverable aircraft. One surge took place in July 2011 on Armavia aircraft EK95015, by which time the airframe had amassed 617 flight hours in 250 flights, since starting revenue services on 21 April.

In 2010 the Russian government provided a rescue package for the ailing engine maker NPO Saturn - the Russian 50:50 partner with Snecma on PowerJet. The rescue package included rouble (Rb) 8.5 billion ($291 million) in additional capital and Rb3.6 billion direct investment into boosting SaM146 production. The government money helped the ­manufacturer deliver its promise to decrease the SaM146's weight to meet Sukhoi's specifications and increase thrust by 5%.

The airframe also needs ­improvement. The SSJ100's operating empty weight is now 27.7t, which implies quite an effort to remove extra kilos and meet the ­original promise of 25.4t. Target maintenance is 750 flight hours for an A-check and 7,500 flight hours for a C-check, but early production examples have needed "extra" inspections after 200 landings, and have temporary restrictions of 4,500 flight hours and 3,000 cycles over five calendar years.

Also, the first 13 deliverable ­airframes - MSN 97007 through 97019 - will require a series of shop visits to check force-bearing ­structural members. Wing outer ­consoles need checks at 2,000 flight hours.

Separately, cylinders, locks and some force-bearing parts of the landing gear system have to be replaced after 1,700 landings.

Although Sukhoi has been ­criticised for its decision to produce 13 "half-able" airframes of the initial series before changing to fully capable versions, the former play a vital role in finding and eliminating teething problems.

Aeroflot agreed to accept them, but only temporarily.

At the Bahrain air show in January, Sukhoi confirmed early-production Aeroflot SSJ100s will be replaced with improved airframes starting later this year. Ex-Aeroflot airframes will be subjected to deep upgrades and modifications before being offered to other airline ­customers.

Aeroflot has dangled the prospect of a follow-on order.