(Reuters) – Wreckage of a Russian Sukhoi aircraft with about 50 people on board was found on Thursday strewn on a steep ridge on a mountain south of the Indonesian capital where it crashed during a demonstration flight. There was no sign of survivors.

The Superjet 100 aircraft, Russia’s first all-new passenger jet since the fall of the Soviet Union, went missing on Wednesday about 40 miles south of Jakarta. It was carrying Indonesian businessmen, eight Russians, including embassy officials, pilots and technicians, and journalists.

A rescue helicopter spotted debris on the side of the dormant Mount Salak volcano after the search was resumed early on Thursday.

An Indonesian air force unit was preparing to drop a team from a helicopter onto the ridge in search of survivors, air force spokesman Yunis said.

Soldiers, some carrying climbing ropes, also trooped up forested slopes towards the crash site, a Reuters witness said.

“The airplane crashed at the edge of Salak mountain … An investigation must be done immediately and thoroughly,” President Susilo Bambang Yudhoyono told a news conference.

Those on board included eight crew and 42 guests, according to figures from the Russian embassy, Sunaryo, chairman of Sukhoi’s Indonesian agent, PT Trimarga Rekatama, said.

A picture taken from the rescue helicopter that found the debris and seen by Reuters appeared to show that the plane flew into an almost vertical wall of rock on an inaccessible part of the mountain.

Small pieces of white debris could be seen scattered down an exposed stretch of cliff surrounded by forest. It would take at least six hours to walk to the site, rescue officials said.

Radio contact with the aircraft was lost at about 4:00 a.m. EDT (0800 GMT) on Wednesday after it descended to 6,000 feet near Mount Salak, which rises to 7,254 feet above sea level, a rescue official said.

AIRCRAFT FOR EXPORT

The aircraft made two demonstration flights on Wednesday.

It returned to Halim Perdanakusuma airport, east of Jakarta, after the first flight where some people got off because it was the time for Muslim prayers and then got left behind, according to Sunaryo. Others who had not planned to fly got on board.

Sukhoi, which has orders for 170 planes worldwide, plans to produce up to 1,000 Superjets, primarily for foreign markets.

It aimed to sell 42 planes to Indonesia, which is seeing a fast-expanding aviation market that aims to tap travel by a growing middle class in the world’s fourth-most populous nation.

Indonesia’s Sky Aviation signed a commitment last August to buy 12 of the Sukhoi Superjet 100s.

“We’re currently concentrating on the plane crash as some of our staff were in the plane. We are waiting for the investigation by the authorities, whether it’s human error or plane issues,” said Sutito Zainudin, general manager marketing of PT Sky Aviation.

“We will take further action about the Sukhoi after the investigation is completed,” Zainudin said. A state-run newspaper in Vietnam said Laos was the first country in Southeast Asia to have placed an order for the aircraft.

The jet was developed with Western design advice and technology from companies including Italy’s Finmeccanica, as well as avionics and engine equipment from French aerospace firms Thales and Safran.

Built in a converted corner of a Sukhoi fighter factory in Siberia, the Superjet was unveiled in 2007 as part of a drive to restore pride in Russia’s aviation industry, but it ran into a series of development delays.

The Superjet 100, with a capacity of 68-103 passengers, is already in service with Russia’s Aeroflot and Armenian carrier Armavia and is half way through a 15,500-km (9,630-mile), six-nation Asian tour to try to drum up more international customers.

The aircraft is being marketed internationally in partnership with Finmeccanica subsidiary Alenia Aeronautica.

SOURCE: REUTERS