Sukhoi engages in engine shuffle as Superjet limps to finish line

 - February 23, 2010, 5:03 AM

Sukhoi Civil Aircraft (SCAC) managed to fly the fourth Superjet 100 prototype for the first time on February 4, notwithstanding continuing delays associated with the airplane’s engines, built by the joint venture between France’s Snecma and Russia’s NPO Saturn known as Powerjet. During an impromptu program update issued to AIN on the third day of last month’s Singapore Air Show, a Sukhoi representative said the company removed the pair of SaM146 turbofans originally used on the first prototype–which at the time had flown some 280 times–and installed them on the fourth flying example, S/N 95005. By early last month Sukhoi had taken delivery of just six SaM146s over the course of nearly two years.

Assembled in Rybinsk by Powerjet partner Saturn, the engines have proved a proverbial thorn in the side for Sukhoi and the Superjet International partnership ever since the Russian engine maker encountered a brush with financial insolvency and a shift in management control last year.

In addition, Saturn had failed to meet quality specification for certain low-pressure components, most notably fan blades, forcing Snecma parent Safran to outsource their manufacture to French suppliers. Now Saturn needs to hire between 200 and 300 engineers to compensate for the resulting exodus of employees from the plant during last year’s financial crisis.

Happily for Saturn and the Powerjet team, the Russian government intervened with monetary support and Safran dispatched a special team of engineers to Rybinsk to help settle the technical difficulties. Still, according to the SCAC spokesperson, Sukhoi did not expect the seventh and eighth SaM146s to arrive at the Superjet’s final assembly plant in Komsomolsk-on-Amur, in Russia’s far east, until this month. With months worth of testing delayed due to the engine woes, Sukhoi now doesn’t expect to gain Russian certification for the Superjet until at least July. Even then, a lack of ready production airplanes means that launch customers Aeroflot and Armenia’s Armavia likely won’t take first deliveries until close to year-end.

While the first airframe sits idle, having finished its certification testing and now devoid of engines, the other three prototypes will need to fly 75 times each month for at least the next four months to achieve type certification. The fourth flying prototype–captained by Sukhoi Civil Aircraft test pilots Sergey Korostiev and Alexander Ivanov on its two hour, 45-minute maiden mission–has undergone all the modifications needed to match the final standard certificate configuration, according to SCAC.

As part of its certification campaign, S/N 95005 must undergo what Sukhoi described as a complex evaluation of onboard equipment and avionics. The airplane will also perform failure safety tests, fire protection trials and testing associated with its inert gas system for EASA certification. It will also serve as a pilot trainer for the type’s first customers, including Aeroflot. The first conference on crew training for Aeroflot took place last September, according to SCAC.

All told, the program has logged more than 1,300 hours and 500 flights since the first airplane performed its maiden mission on May 19, 2008, from Komsomolsk-on-Amur. After successful completion of factory flight tests, the airplane began its certification testing campaign on October 24 that year. The second prototype took to the skies exactly two months later, on Dec. 24, 2008. SCAC flew the third prototype for the first time on July 25 last year. The program has drawn firm orders for 122 airplanes, including 30 from Aeroflot.