CIGOMBONG, Indonesia (AFP) -- The wreckage of a Russian Sukhoi passenger jet was found Thursday on the side of a dormant Indonesian volcano and authorities said there was no chance any of the dozens aboard could have survived.

A helicopter pilot spotted the debris of Russia‘s first post-Soviet civilian plane scattered over rocks and trees on the sheer face of Mount Salak outside the city of Bogor, officials said.

The twin-engine Superjet 100 vanished from radar screens south of Indonesia’s capital Jakarta on Wednesday, 50 minutes into what was meant to be a short flight to show off its capabilities to prospective buyers.

Initial efforts to locate the jet proved fruitless but the crew of an Indonesian military helicopter discovered the crash scene after the search resumed at first light on Thursday, officials said.

They said rescuers were trying to get to the wreckage by land and air, but that heavy fog was hampering visibility for helicopters and that reaching the crash site could take several hours by foot.

National rescue agency spokesman Gagah Prakoso said there was no sign so far of any survivors, and transport ministry spokesman Bambang Evian said there was no chance anyone could have lived.

“Looking at the location... the chance of surviving is none,” Evian told AFP. “But we are still waiting for a miracle.”

Devastated relatives of those aboard the ill-fated aircraft gathered at the Halim Perdanakusuma airport in Jakarta -- used for military and some commercial flights -- where the Sukhoi had taken off the day before.

Some wept quietly as friends tried to console them, while others sat in a state of shock, staring into the distance. Authorities took DNA samples to help in identification if remains are found.

A teary-eyed Yenni Cipta, 38, recalled that when her father, an aviation worker, had said farewell on Wednesday he had jokingly told her children:

“Grandpa is going to a faraway place.”

Reports of the number on board varied, with local rescue officials saying the plane was carrying 46 people and Trimarga Rekatama, the company responsible for inviting the passengers, saying 50 were on board.

Those aboard were mostly Indonesian aviation representatives, but also included eight Russians -- four of them crew and four Sukhoi employees -- plus an American and a Frenchman, officials said.

The Sukhoi Superjet, a new passenger aircraft, is crucial to Russia‘s hopes of becoming a major player in the modern aviation market, and a major accident would be the first disaster involving the type.

National search and rescue chief Daryatmo, who goes by one name, said the helicopter pilot had sighted the Sukhoi logo among the debris.

“We spotted the fragments at the coordinates where we lost contact with the plane,” he told a news conference.

The mountainous Mount Salak region rises 2,000 meters above sea level, some 80 kilometers southeast of Jakarta. Indonesian officials have said the Sukhoi descended to about 6,000 feet shortly before it vanished.

The debris was found on the side of Mount Salak about 1,800 meters above sea level, said Lieutenant Colonel Mukhlis, a local military commander.

“We don’t know how big it is, what part of the plane, and the condition of the passengers,” he added.

The wreckage was spotted at about 9:30 a.m., but by 3:00 pm rescuers still could not reach the site.

“Helicopters still cannot reach the site because of heavy fog, and our rescue teams are on their way on foot,” he said.

The rescue agency‘s Prakoso said the operation could be deferred to Friday if the weather does not improve before dark.

President Susilo Bambang Yudhoyono told reporters that “all efforts must be made in this rescue operation... and the priority must be to save survivors, if any”.

The demonstration flight was part of an Asian tour to promote the aircraft, which is a joint venture between Sukhoi and Italy’s Alenia Aeronautica. It made its first commercial flight last year.

So far it is being flown by two airlines, Russia‘s Aeroflot and Armenia’s Armavia, but orders have reportedly been confirmed with more, including Indonesia‘s Kartika Airlines and Sky Aviation.