- Fransiskus Subihardayan hung onto water hyacinths in Lake Toba
- He was found after two days; the four others in the helicopter are still missing
Fransiskus Subihardayan, 22, had stripped down to his underwear and entwined himself in the volcanic lake's water hyacinths in his efforts to keep afloat, said Bambang Supriyadi, an official from Indonesia's national search and rescue agency.
The other four people aboard the helicopter also survived the crash Sunday and had initially been in the water with Fransiskus, he told search and rescue officials. But they gradually became separated, leaving him hanging onto the hyacinths alone in Lake Toba, in North Sumatra province.
A search team found Fransiskus waving amid the plants early on Tuesday afternoon and took him to a local hospital. Supriyadi on Wednesday described the survivor's condition as weak but somewhat better than when he was first discovered.
He suffered no major injuries during his ordeal, with only some small sores on his feet, the official said.
Search continues in region's largest lake
Supriyadi said that initial investigations, including Fransiskus' account, indicate that the helicopter lost power when it hit turbulence over the lake.
It stayed afloat for a few minutes after hitting the water, allowing Fransiskus and the others on board to open a door and jump out.
About 800 searchers are taking part in the continuing hunt for the other four people who were on board the helicopter. The search teams include navy, police and army personnel as well as local residents.
The helicopter was on a local charter flight operated by the company that owns it, Penerbangan Angkasa Semesta. On board were a pilot, an engineer, Fransiskus and two other passengers.
Ringed by volcanic mountains and with a big island at its center, Lake Toba is the largest lake in Southeast Asia.