From wikipedia
On 9 May 2012 a Russian Sukhoi Superjet 100 airliner, on a demonstration flight with 37 passengers and eight Russian crew members on board, crashed after it took off from the Halim Perdanakusuma Airport in Jakarta, Indonesia, killing everyone on board. About twenty minutes after the take-off, the crew requested permission to descend to 1,800 metres (5,900 ft), which was granted. This was the last contact that Air Traffic Control had with the aircraft, which was then about 139 kilometres (75 nmi) south of Jakarta, in the vicinity of the 2,211-metre-high (7,254 ft) Mount Salak, a mountain higher than the requested flight level.[198] After an extensive search, rescuers concluded, based on the widespread debris field on the side of a ridge, that the aircraft directly struck the rocky side of Mount Salak and there was "no chance of survival".
An official inquiry into the crash found that the plane's automatic collision avoidance system was working, but had been ignored by the pilot, who was possibly distracted by his conversation with a potential customer for the aircraft.