The word “error” might be a little misleading; fragments of conversation point towards the crash being the result of test pilot Alexander Yablontsev's attempt to show off the abilities of the Superjet to the dignitaries onboard. The Superjet was on a six-nation tour of Asia to drum up sales for the first newly-designed passenger jet to come out of Russia since the end of the Soviet Union. While flying across the rugged, mountainous interior of Java, Indonesia, the Superjet encountered a thunderstorm. Rather than trying to fly above the weather, Yablontsev instead requested that flight controllers allow him to descend to 1,800 meters; Indonesian flight controllers approved this odd request and moments later the Superjet flew into the side of a mountain. This decision has led to speculation that Yablontsev was somehow trying to show off the handling of the Superjet, not realizing that there were mountains in his flight path.
This theory seems partially confirmed by a snippet of recording from the black box just before the crash. According to a report in Russia’s Moskovsky Komsomolets, after Yablontsev made his course adjustment, a crewmember is heard to say something along the lines of: “commander, we can't go there, there's a mountain,” though the paper did not provide a direct quotation.
This is both good and bad news for the Russian aviation industry. On the plus side, it is proof that there is nothing mechanically wrong with the Sukhoi Superjet; the project on which Russia has basically bet the entire future of their domestic civilian aviation industry. But on the downside, Yablontsev's reckless decision to descend to a lower altitude while in a storm over unfamiliar terrain will do nothing to improve confidence in Russian aviation, which already has a reputation for lax safety procedures and has suffered a series high-profile crashes in recent years including one that have killed Polish President Lech Kaczyński and his diplomatic party and another that killed the entire Lokomotiv Yaroslavl hockey team.