Gen. Eduardo Mosqueira said Uruguay, Argentina, Brazil and the United States had each lent planes to the search following Monday's disappearance. At least 13 aircraft and several ships were scouring the area where the plane was believed to be when radio contact was lost.
"We'll continue searching 24 hours a day, both night and day, with the resources at our disposal," Mosqueira told The Associated Press.
Officials said the plane had taken off in favorable conditions Monday afternoon, though it was flying in an area notorious for rapidly changing conditions, with freezing temperatures and strong winds. Seven hours after contact was cut off, the air force declared the plane a loss, though there was no sign of what happened to it.
The C-130 Hercules carried 17 crew members and 21 passengers, including three civilians. They were en route to check on a floating fuel supply line and other equipment at the Chilean base.
President Sebastián Piñera said via Twitter that he was with his defense and interior ministers at the air force headquarters monitoring developments.
"My thoughts and prayers are with the families of the 38 crew members and passengers," said Piñera, who cancelled a trip to attend Tuesday's inauguration in Argentina of President Alberto Fernández.
The three civilian passengers included a 24-year-old who was embarking on a research project and two employees of a private company. One passenger was a woman.
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.
The plane took off at Monday afternoon from the southern city of Punta Arenas, more than 3,000 kilometers (1,860 miles) from the capital of Santiago. Contact was lost at 6:13 p.m., the initial announcement said.
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.
"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 6 meters (20 feet) high.
Holding out hope of survivors, officials said the plane was equipped with four rafts that could hold up to 20 passengers each if it went down at sea.
The four-engine C-130 is a "military workhorse" first manufactured and flown in the late 1950s.
While the missing plane is more than 40 years old, "Well maintained, the age of the airplane should not necessarily be a problem," said former US Airways pilot John M. Cox, who is CEO of the consulting firm Safety Operating Systems. "A well-maintained airplane can fly 50-plus years. They're designed that way."
Answers to what may have gone wrong could be in the plane's flight data recorder, he said, but finding the wreckage in the sea could prove to be a large challenge for searchers.
Chile maintains a scientific base on Antarctica, conducting research on climate change and medicine. Military planes provide the only travel possibilities, frequently transporting civilians.