Two rescue helicopters were flying close to the route the Piper PA-31 Navajo aircraft was taking before it lost contact with authorities Friday morning minutes after takeoff from an airport in the city of Samarinda on Borneo, said the airport’s chief, Rajoki Aritonang.
Aritonang said that satellite images showed the aircraft’s latest position on Friday afternoon was within the Kutai National Park, about 30 kilometers (18 miles) east of Bontang, a mining town, and that the plane was running critically low on fuel.
Rugged, forested terrain and bad weather prevented 75 rescuers from reaching the site by foot, and no trace of the plane has been found, said Indonesian search and rescue agency spokesman Gagah Prakoso.
The plane was chartered by Elliott Geophysics International, a Perth, Australia-based company, and failed to return from a surveying mission in Bontang.
It was carrying the pilot, two other Indonesians and the company’s Australian owner. They left Samarinda on Friday morning for a 90-minute flight to survey a coal mining site, Aritonang said.
Air flight is the main source of transportation on Borneo, the world’s third-largest island.
Indonesia, a sprawling archipelagic nation of nearly 240 million, has been plagued by transportation accidents in recent years, from plane and train crashes to ferry sinkings. Overcrowding, aging infrastructure and poor safety standards are often to blame.