TOKYO (AP) -- Nearly every navy with a presence in Southeast Asia is involved in the extensive search for the Malaysia Airlines Boeing 777 that disappeared early Saturday. Some details on the key responders and their capabilities:
The U.S. Navy is easily the biggest and best equipped Navy in the Pacific and was fast to participate. Two San Diego-based destroyers are searching areas where they were directed by the Malaysian government. As of Wednesday, the USS Kidd was searching in the southwest section of the Gulf of Thailand and the USS Pickney was in the northeast area, between Thailand, Cambodia and Vietnam.
The Kidd's two HM-60R Seahawk helicopters have been flying sorties from dawn to dusk in search of debris. According to the U.S. 7th Fleet, the helicopters can search a 400- to 600-square-nautical mile area during a typical 3?-hour sortie, depending on sea and weather conditions and the size of object it's trying to find. Its onboard sensors can detect small objects in the water, in addition to the crew using binoculars or the naked eye. The Seahawks also have forward-looking infrared cameras for night use.
A Navy P-3C Orion aircraft has been searching over both the Straits of Malacca and the Gulf of Thailand. The P-3C can search for extended periods and cover 1,000-1,500 square miles every hour. On-board sensors allow the crew to clearly detect small debris in the water.
Four Chinese naval vessels are joining the effort. The Jinggangshan is the largest in the Chinese navy and has a large flight deck capable of launching several helicopters. An air force plane was dispatched to search for signals from the flight's black box.
The People's Liberation Army Newspaper, run by the ruling party's military commission, said Beijing also sent four helicopters and four civilian search vessels. The Kunlunshan -- another amphibious landing ship with two helicopters -- arrived at the designated area in the Gulf of Thailand early Thursday morning.
China plans to expand the scope of its search in the northwest toward the Gulf of Thailand and to cover 5,000 square nautical miles (17,000 square kilometers) in the Gulf of Thailand, the military newspaper said.
"That is equivalent to a medium-sized city, and we must be meticulous in our work because of the higher demands to conduct the search in such a vast area," Liu Zhonghu, captain of Jinggangshan, told the newspaper.
On state-run China Central Television, PLA navy officers said the helicopters took off from the Jianggangshan and Kunlunshan to search, the ships were using underwater sonar and robots to detect the plane, and the crews have been surveying the sea.
THE PHILIPPINES & VIETNAM:
Despite its meager resources, the Philippine military immediately dispatched search and rescue vessels and aircraft into the South China Sea southwest of Manila within hours of the plane being reported missing Saturday.
The Philippines' largest and newest naval vessel, the BRP Gregorio del Pilar, a former U.S. Coast Guard cutter, was deployed on Wednesday to replace two smaller patrol boats that returned to port for refueling and resupply, said 1st Lt. Cherry Tindog, spokeswoman for the military's Western Command.
She said an air force Fokker 27 that searched on Saturday and Sunday was replaced by a navy Islander on Monday. A C-130 was deployed on Tuesday. The navy Islander and the Gregorio del Pilar were both searching on Thursday.
Tindog also said all fishermen and fishing boats in the area have been advised to help in the search.
Meanwhile, in Hanoi, Lt. Gen. Vo Van Tuan, deputy chief of staff of Vietnamese People's Army, told The Associated Press that Vietnam has dispatched for the first time a helicopter to scour jungles of U Minh in southern Vietnam after the massive sea search found no clues.
"We have instructed related regional military commands to deploy searches on land from the beginning," he said. "Now we use helicopters for searches in areas few people could access." He said the searches by helicopter will be widened to other jungles in the south central region.
MORE ON THE WAY:
Japan, which has been increasing its effort to participate in regional humanitarian missions, said it will deploy two C-130 transport planes and two P-3C aircraft to the area. A spokesman for Japan's Defense Ministry on Thursday said the transport aircraft are already on site and the P-3Cs will be deployed as soon as possible unless the situation changes.
Neighbors Indonesia, Singapore and Brunei have already provided ships, and Singapore is planning to add more aircraft. Thailand has contributed helicopters, while Australia has offered two P-3C aircraft and India is reportedly mobilizing coast guard vessels.
AP writers Didi Tang in Beijing, Tran Van Minh in Hanoi, Niniek Karmini in Jakarta and Oliver Teves and Jim Gomez in Manila contributed to this report.