Two Navy sub-hunter P-8 Poseidon aircraft and rescue submersibles on board a chartered ship continued to assist in the search for the missing Argentine submarine with 44 sailors on board that last sent out a message nine days ago, U.S. Southern Command said Friday.
The P-8s were flying out of Commandante Espora airbase near Bahia Blanca, about 355 miles southwest of Buenos Aires, while the UUVs, or Unmanned Underwater Vehicles, and side-scan sonar equipment were on board the chartered Norwegian ship Skandi Patagonia in the South Atlantic, said Navy Cmdr. Erik Reynolds, a SouthCom spokesman.
The continuing search was being conducted against fading hopes that the crew of the 216-foot, diesel-electric ARA San Juan may have survived what Reynolds described as a "hydro-acoustic anomaly" that was recorded by undersea monitors, just after the last message from the sub on Nov. 15.
The German-built submarine had been en route from the Ushuaia, a port at the Tierra del Fuego southern tip of South America, to Mar del Plata about 250 miles southeast of Buenos Aires when the last communication was recorded.
Shortly after the last message, the Comprehensive Nuclear-Test-Ban Treaty Organization, based in Vienna, said that two of its hydro-acoustic stations detected an "unusual signal" deep in the Atlantic near the submarine's last known location about 270 miles off the Argentine coast.
The Organization, which monitors for nuclear events, said an analysis of its data showed that the signal was consistent with an explosion. The U.S. Navy has reached a similar conclusion from its own analysis, Reynolds said.
Capt. Enrique Balbo, a spokesman for the Argentine navy, told reporters Thursday that "According to this report, there was an explosion. We don't know what caused an explosion of these characteristics at this site on this date."
He said that the search assisted by the U.S., Chile, Brazil and Britain would continue amid mounting anger from the families of the crew over previous false reports that the location of the submarine may have been detected and that additional communications had been received.
The families' ire has been heightened by revelations of the parlous state of Argentina's military since the sub went missing. Argentina's fleet of four P-3 Orion sub-hunters, which could aid in the search, have been grounded because of poor maintenance.
Last week, the Navy ordered the Undersea Rescue Command [URC] based in San Diego to deploy to Argentina to support the search.
Three Air Force C-17 Globemaster III and one U.S. Air Force C-5 Galaxy left San Diego on Nov. 18 with a Submarine Rescue Chamber [SRC} and a Remotely Operated Vehicle [ROV] aboard for Commodoro Rivadavia in Argentina's Patagonia province about 1,080 miles south of Buenos Aires.
The Navy also deployed a Pressurized Rescue Module [PRM] and supporting equipment on board additional flights.
The SRC is a rescue chamber designed during World War II, which can rescue up to six persons at a time and reach a bottomed submarine at depths of 850 feet, SouthCom said in a statement. The PRM can dive down 2,000 feet for docking and mating with a submarine settled on the ocean floor, and can rescue up to 16 personnel at a time.
Both the SRC and the PRM are operated by two crew members and mate with the submarine by sealing over the submarine's hatch, allowing sailors to transfer safely to the rescue chamber.
-- Richard Sisk can be reached at Richard.Sisk@Military.com.