Some six weeks after Brussels Airlines prematurely ended SSJ100 operations due to what it called long downtimes and aircraft complexity, Sukhoi Civil Aircraft (SCAC) found itself addressing further aggravation, this time involving the alleged use of poor quality titanium parts in roughly a quarter of the active Superjet fleet. On Wednesday, Russian media reported that about 50 aircraft might have developed micro cracks in landing gear and engine and flap attachment points allegedly made of uncertified titanium alloy. An airworthiness directive issued by the Russian civil aviation authority Rosaviatsiya on December 29 appears to support the claims.

The directive advised SCAC to perform inspections of affected aircraft to assess the manufacturing quality of the SSJ100 structural members possibly made of “titanium alloys of unconfirmed origin.” The order calls for inspection when the aircraft in question undergoes scheduled maintenance checks upon logging 750 flight hours or within 100 calendar days. According to the directive, metal supplier VSMPO-Avisma had failed to timely confirm the manufacturing quality of titanium ingots supplied to SCAC and its industrial partners.

In reaction to the order, SSJ100 chief designer Vladimir Lavrov drafted a schedule of inspections on a total of 48 airframes, including 15 in service with Aeroflot, eight with Azimuth Airlines, nine with Yamal Airlines, and four with IrAero. Inspections using endoscopes started in late January.

Reacting to publications in the local media, SCAC issued a statement on February 19 indicating it had addressed concerns about the questionable quality of the metal in the Superjet parts. The company’s statement refers to a February 6 Rosaviatsiya airworthiness directive that indicates that the manufacturer had inspected all the suspect titanium parts and confirmed their quality. The directive also refers to the results of tests performed on the chemical composition of the suspected titanium ingots at the VASO factory in Voronezh, which confirmed compliance to the recipe prescribed for the particular alloy in question.

In its own statement, SCAC pointed out that the inspections performed on the fleet involved only a one-time visual assessment of certain structural members during routine maintenance. The manufacturer claims that it found no evidence of any use of substandard quality materials. Effectively, the inspections rendered the aircraft “fully compliant” to specification and in good working order.

In December, the manufacturer pledged to fight parts counterfeiting through the introduction of a so-called Aircraft Electronic Passport (AEP). “Regretfully, counterfeiting is still alive,” said SCAC CEO Alexander Roubtsov at the time. “Surely, the electronic 'passportization' will help us fight it.”