As divers searched the muddy bottom of Alabama's Mobile Bay, a salvage ship was dispatched Wednesday to the sunken wreckage of a U.S. Coast Guard helicopter that crashed on a training mission, leaving one crewmember dead and three others missing.
Officials said the search would continue through the night throughout the choppy bay in the hope of finding survivors.
The MH-65C helicopter crashed Tuesday evening near Point Clear, Ala. One crewmember was found unresponsive and later declared dead, the Coast Guard said.
The crewmembers were outfitted with survival gear called "dry suits" for the water which officials said was around 60 degrees Fahrenheit.
Chief Petty Officer John Edwards said all the crew members received extensive training in emergency escape. He declined to say how long a person could typically survive in a dry suit in 60-degree water, but said, "They look at beyond the survivability charts."
The man who died was a rescue swimmer, said Capt. Don Rose, commanding officer of Coast Guard Sector Mobile. Rose said rescuers tried to revive the rescue swimmer when they found him, but were unable to. The three missing crewmembers were the pilot, the co-pilot and the flight mechanic.
Names of the four crewmembers have not been released.
Divers swam to the wreckage in about 13 feet of water, but were unable to gain access to its fuselage.
A Coast Guard official told the Mobile Press-Register that the forward end of the helicopter is submerged in mud at the bottom of Mobile Bay and rescue divers have had trouble getting access to the crew cabin. Press-Register reporters at the scene saw the tail of the helicopter sticking out of the water. The aircraft appears to have crashed nose-first into the bay, the newspaper reported.
A privately owned 57-foot towing vessel called the Ben. R. Johnson was en route to the scene from Mobile, Edwards said. He said they did not expect to pull up the wreckage right away, but were keeping it cordoned off and secure.
Emergency responders from surrounding counties helped with the search Tuesday and Wednesday, heading out from shore in dozens of boats. Some were equipped with sonar and brought divers and search dogs. They said the water has been choppy.
The accident comes less than three years after an HH60 Jayhawk helicopter crashed off James Island in Washington state in July 2010, killing three Coast Guard crew members.
Tuesday's wreck also brought back memories in south Alabama of a 1981 crash of a Coast Guard helicopter near an airport in Mobile that killed all four people aboard.
The MH-65C, commonly referred to as the Dolphin, is a twin-engine, single-rotor helicopter often used in search and rescue operations. A Coast Guard website said the typical crew includes two pilots, a flight mechanic and a rescue swimmer.
The Coast Guard had major problems with engine failures in the French-designed aircraft and began replacing the helicopter's power plants in 2004, according to a report from the General Accounting Office. Pilots reported 67 cases of engine failures or other problems over a six-month period ending in February 2004, the report said.
The Coast Guard began an engine replacement program costing as much as $250 million to solve the problem, according to the report. Originally known as the HH-65, Dolphin helicopters with new engines, communication equipment and weapons were designated as the MH-65C, the type of helicopter that went down in Mobile Bay.
Edwards said the helicopter that crashed received the improved engine several years ago, but it wasn't immediately clear exactly when.
"They're new engines as far as engines go, but they're not brand-spanking new," he said. The improvements seem to have fixed the engine problems from years ago since no new rash of failures or crashes has occurred, he said.
The last deaths in an HH-65 were in September 2008, when four crew members died when a helicopter went down off the coast of Hawaii, according to a Coast Guard database. A rescue cable snapped during a training mission and metal flew into the rotor blades, an investigation found.
The aircraft that crashed Tuesday had departed the Aviation Training Center in Mobile on a training mission, Petty Officer 2nd Class Elizabeth Bordelon said.
Coast Guard officials say it went down about two to three miles southwest of Point Clear.
"Our thoughts and prayers are with the families of the crewmembers during this difficult time," Capt. Don Rose, commanding officer of Coast Guard Sector Mobile, said in a statement.
The Coast Guard said two helicopters, an airplane and several vessels were involved in the search.
National Weather Service officials said winds in the area Tuesday night were southeast at about 15 mph.
Associated Press writer Jay Reeves contributed to this story from Birmingham, Ala.