Russia's first all-new passenger jet since the fall of the Soviet Union, a Superjet 100 aircraft, went missing on Wednesday about 40 miles (64 km) south of Jakarta.
It was carrying Indonesians, including journalists and businessmen, eight Russians, including embassy officials, pilots and technicians, two Italians, one French citizen and one American, said Vladimir Prisyazhnyuk, the head of Sukhoi Civil Aircraft.
"We haven't found survivors," Gagah Prakoso, spokesman of the search and rescue team, told Indonesia's Metro TV.
Radio contact with the aircraft was lost at about 0800 GMT on Wednesday after it descended to 6,000 feet (1,800 metres) near Mount Salak, which rises to 7,254 feet (2,200 metres) above sea level, a rescue official said.
A search resumed at dawn on Thursday and a rescue helicopter later spotted debris on the side of the dormant Mount Salak volcano, sending multiple teams on a trek across steep and heavily forested terrain to reach the site.
A picture taken from the helicopter appeared to show that the plane hit the top of an almost vertical wall of rock. Small pieces of white debris could be seen scattered down an exposed stretch of cliff.
"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.
AIRCRAFT FOR EXPORT
Sukhoi's chief civil test pilot, Alexander Yablontsev, and his co-pilot, Alexander Kochetkov, flew the plane, Superjet International, the Italian-led venture responsible for marketing the plane to the West, said in a statement on its website.
Yablontsev had accumulated 10,000 flight hours and commanded the Superjet on its maiden flight in 2008.
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.
The crash came 45 years after a Dutch-built Fokker F-27 flew into a hill in the Philippines on a promotional sortie due to probable pilot error, said the Flight Safety Foundation.
"There have been losses on demonstration flights and they are not generally the fault of the airplane. But without more information it is impossible to know the circumstances here," said Paul Hayes, safety director at aviation consultancy Ascend.
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 Sukhoi Superjet 100s.
"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 (purchase) 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 (SIFI.MI), as well as avionics and engine equipment from French aerospace firms Thales (TCFP.PA) and Safran (SAF.PA).
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.