Let's just say this isn't the kind of publicity that the Russian aerospace company Sukhoi was looking for.

BBC:

A new Russian passenger jet carrying 46 people has gone missing on a demonstration flight in Indonesia, after taking off from Jakarta.

The Sukhoi Superjet 100 disappeared from radar screens 50 minutes into what was meant to be a brief flight.

An eyewitness reported seeing a low-flying plane flying towards a mountain but did not hear any explosion.

Aerial searches for the plane have been hampered by darkness and wet weather.

But rescuers have continued looking for the plane on the ground.

The plane, which took off at 07:00 GMT, is believed to have had about four hours' fuel aboard, the BBC's Karishma Vaswani reports from Jakarta.

Gagah Prakoso, spokesman for Indonesia's national search and rescue agency, said 46 people had been aboard the plane, which vanished from radar near Bogor, a city in West Java province.

He told BBC News it was unclear who was on board because they were people invited by Sukhoi, but they were "likely to be reps of Indonesian airlines".

Eight of those on board are Russians, according to Russian blogger Sergey Dolya, who was accompanying the Sukhoi delegation and broke news of the plane's disappearance.

It doesn't look good:

"At 14:50 it dropped from 10,000ft [3,000m] to 6,000ft," the agency told AFP. Its location was described as being near Mt Salak (7,200ft, 2,200m).

Rear Marshal Daryatmo, chief of the national search and rescue agency, said the crew had not had time to explain why they wanted to change course.

An eyewitness reported the plane passing low over his house headed for the mountain, but no explosion was heard.

Sukhoi is a military plane builder. The Superjet is it's first effort to crack the civilian aviation market.