The Chilean Air Force said Monday that it had lost contact with an Antarctica-bound plane with 38 people on board. Rescuers from multiple countries searched the area Tuesday in hopes of finding survivors or clues about the plane's disappearance. 

The plane departed at 4:55 p.m. local time from Punta Arenas and lost contact with operators at 6:13 p.m. local time, officials said. More than seven hours after losing radio contact with the C-130 Hercules, the Air Force declared the plane had crashed but said the search for wreckage continued by both Chilean and partnered forces, in the air and on the water, "with hope of finding any survivors."

The Air Force said it was contacting family members of those on board the plane "to keep them informed of this sad situation which affects both the Force and the nation." The Air Force on Tuesday released the names of the plane's 17 crew members and 21 passengers.  

Of the passengers, the Air Force said in a tweet, 15 were members of the Air Force, three were from the country's army, two were private citizens from the same company and one was from the University of Magallanes in Punta Arenas. The crew were members of the Air Force.

The plane was traveling to Antarctica to help maintain facilities at Base Presidente Eduardo Frei Montalva, a Chilean base on the northern tip of the continent, according to the earlier statement. The plane was scheduled to arrive at 7:17 p.m. local time, according to a projection released by the Chilean Air Force on Twitter. 

President Sebastián Piñera said on Twitter Monday that he was with his defense and interior ministers at Air Force headquarters monitoring developments. 

"My thoughts and prayers are with the families of the 38 crew members and passengers," Piñera said in a Tuesday tweet, adding that he had canceled a planned trip to attend Tuesday's inauguration in Argentina of President Alberto Fernández.

The two pilots had extensive experience, according to the Chilean Air Force, which said that while the plane was built in 1978, it was in good condition. The Air Force said it flies this route monthly.

Drake's Passage, the sea between the southern tip of South America and Antarctica, is infamous for severe weather conditions, including ferocious storms. But the Air Force said late Monday that the weather was good when the plane began its flight, or the mission would not have been carried out.

General Eduardo Mosqueira of the Fourth Air Brigade told local media that a search was underway and a ship was in the general area where the plane should have been when contact was lost. "Antarctica is different. It's hard to fly because of changing conditions," said Mosqueira, who added that he had personally flown to the continent with one of the missing pilots.

The aircraft would have been about halfway to the Antarctic base when it lost contact, Mosqueira said, adding that no emergency signals had been activated. On Tuesday, crews encountered low visibility and waves up to 20 feet high.

Holding out hope of survivors, officials said the plane has four rafts that could carry up to 20 passengers each if it went down at sea. The Chilean Air Force said planes from Argentina and Uruguay were assisting with the search.