The first Sukhoi Civil Aircraft Corp. Superjet 100 regional jet is believed to have crashed in Indonesia during a demonstration program.

Contact with the aircraft was lost as the aircraft was returning to Halim Pedanakusumah Airport in Jakarta around 20 minutes after takeoff. Last contact with the aircraft was around 2:33 p.m. local time with the aircraft descending from 10,000 ft. to 6,000 ft., the Indonesian search and rescue agency says. The crash site is believed to be in the vicinity of Mount Salak, with the agency giving the last know coordinates as 106 43’ 15” East and 06 43’ 08” South.

The aircraft had 44 persons onboard, including eight crew members. Search and rescue operations have commenced but are hobbled by the onset of darkness.

The aircraft was on an Asian tour to help drum-up sales interest in the regional jet. Several Asian airlines have already committed to the program, including Indonesia’s Kartika Airlines (two airline employees were on the flight).

The mishap aircraft is SN95004, which replaced SN95005 which began the tour. Prior to its arrival in Indonesia, the tour included stops in Burma, Pakistan, and Kazakhstan, and the aircraft was due to head to Laos and Vietnam after. At the outset of the tour, Sukhoi said chief test pilot Alexander Yablontsev and his co-pilot Alexander Kochetkov would be in charge.

The incident comes as Sukhoi was looking to move the program to a new level, with production slated to ramp up after several years of below-planned output. Moreover, the aircraft maker recently received the Mexican certification for the regional jet to allow Interjet, its first western operator, to commence use of the aircraft this year.

Aeroflot and Armavia are the only Superjet operators so far. The total in-service fleet has now reached seven aircraft.