JAKARTA (AFP/REUTERS) - An Indonesian passenger plane carrying 54 people lost contact with air traffic control on Sunday during a flight in the rugged and remote easternmost province of Papua, the country's search and research agency Basarnas said.
The Trigana Air ATR 42 turboprop plane lost contact just before 3pm local time after taking off from Sentani airport in Papua's capital Jayapura on a flight to Oksibil, due south of Jayapura, the agency said on Twitter.
"We can't confirm it has crashed. We can say contact has been lost with the plane," Basarnas chief Bambang Soelystyo told Reuters by phone.
"It's a Trigana airline plane carrying 54 people, including five crew. We are working to get more details."
According to the official Basarnas Twitter account, the aircraft belonging to Trigana Air Service was carrying 44 adult passengers, five crew members, and five children and infants, and the flight was scheduled to take about 45 minutes.
It had left Jayapura about half an hour before it disappeared, Basarnas added.
Transport Ministry spokesman J. A. Barata confirmed the plane had lost contact, and said it was supposed to arrive at Oksibil airport just after 3pm.
Ten minutes before it was due to land, the plane contacted Oksibil control tower asking to descend, Captain Beni Sumaryanto, Trigana Air's service director of operations told AFP.
But the plane never arrived.
Half an hour later, Trigana Air sent another turboprop plane over the same route to look for the missing aircraft, he said.
"But the weather was very bad, it could not find it and the plane was turned back to Sentani," Capt Sumaryanto said.
He added: "Oksibil is a mountainous area where weather is very unpredictable. It can suddenly turn foggy, dark and windy without warning.
"We strongly suspect it's a weather issue. It is not overcapacity, as the plane could take 50 passengers."
Mr Barata told AFP: "We are not sure what happened to the plane yet and we are coordinating with local authorities.
"The weather is currently very bad there, it's very dark and cloudy. It's not conducive for a search. The area is mountainous."
Basarnas' Jayapura office was coordinating the search, a separate tweet read as dusk set in in the tropics. Search efforts are being hampered by failing light as night falls.
It was not immediately clear if search efforts would continue into the night in the densely forested mountainous region where the aircraft was travelling.
The Jakarta Post reported that the plane is being piloted by Capt Hasanuddin and co-pilot Aryadin. The other three crew members are mechanic officer Mario and female flight attendants Ika and Dita.
Air transport is commonly used in Papua, Indonesia's easternmost province, where land travel is often impossible.
Small aircraft are commonly used for transport in the remote, mountainous province, and bad weather has caused several accidents in recent years.
On Wednesday, a Cessna propeller plane operated by Indonesian company Komala Air crashed in Papua's Yahukimo district, killing one person and seriously injuring the five others on board. Officials suspect that crash was caused by bad weather.
According to the Aviation Safety Network, an online database, the ATR 42-300 had its first flight 27 years ago.
ATR is a joint venture between Airbus and Alenia Aermacchi, a subsidiary of Italian aerospace firm Finmeccanica .
Trigana Air is a small Indonesia airline established in 1991 that operates domestic services to around 40 destinations in Indonesia. It has been on the European Union blacklist of banned carriers since 2007.
Airlines on the list are barred from operating in European airspace due to either concerns about its safety standards, or concerns about the regulatory environment in its country of registration.
The airline has a fleet of 14 aircraft, according to the airfleets.com database.
These include 10 ATR aircraft and four Boeing 737 classics. These have an average age of 26.6 years, according to the database.
Trigana has had 14 serious incidents since it began operations in 1991, according to the Aviation Safety Network's online database. Excluding this latest incident, it has written off 10 aircraft.
Indonesia has a patchy aviation safety record. An AirAsia passenger jet crashed en route from the Indonesian city of Surabaya to Singapore last December, killing all 162 people on board.
The crash prompted the government to introduce regulations aimed at improving safety.
Indonesia's President promised a review of the ageing air force fleet in July after a military transport plane crashed in the north of the country, killing more than 100 people.