Rescuers conduct search operations at the site of plane crash in Tengxian County in southern China's Guangxi Zhuang Autonomous Region
Highlights
- One of the black boxes, believed to be the cockpit voice recorder, was found on March 23
- Investigators said the outer casing of the black box was damaged
- The orange cylinder of the black box was, however, found relatively intact
Hours after the first black box was recovered from the crash site of the China Eastern passenger jet, the search area was expanded for the second black box on Thursday. One of the black boxes, believed to be the cockpit voice recorder, was found Wednesday in southern China, where the plane with 132 passengers onboard had crashed earlier this week. Investigators said the outer casing of the black box was damaged, however, the orange cylinder was relatively intact.
Meanwhile, the search for the second black box was hindered by continuous rainfall in the area.
Searchers have been using hand tools, metal detectors, drones and sniffer dogs to comb the heavily forested and steep slopes. They have found some wallets, identity and bank cards, along with human remains.
The Boeing 737-800 was cruising at 29,000 feet (8,800 meters) when it suddenly nose-dived into a remote mountainous area on Monday, setting off a fire in the surrounding forest that could be seen in NASA satellite images.
No survivors have been found.
Police tape cordons off debris at the site of a plane crash in Tengxian County in southern China's Guangxi Zhuang Autonomous Region
Investigators have said it is too early to speculate on the cause. An air-traffic controller tried to contact the pilots several times after seeing the plane’s altitude drop sharply but got no reply, officials have said.
The China Eastern flight was headed from Kunming, the capital of Yunnan province, to Guangzhou, a major city and export manufacturing hub on China’s southeastern coast.
China Eastern, headquartered in Shanghai, is one of China’s four major airlines.
Why is black box relevant?
Airplanes are equipped with sensors that gather data such as acceleration, airspeed, altitude, flap settings, outside temperature, engine performance, and cabin temperature and pressure. Magnetic-tape recorders can track about 100 parameters, while solid-state recorders can track a lot more.
The black box is generally kept at the backside of the airplane from the security point of view. This box is made of titanium metal and is enclosed in a titanium box which gives it the strength to withstand any shock if it falls in the sea or falls from the height.
Recovering the black boxes — usually painted orange for visibility — is considered key to figuring out what caused any plane crash.
Cockpit voice recorders can capture voices, audio alerts and background sounds from the engine or even switches being moved.
After finding the black boxes, investigators take the recorders to a lab where they can download the data from the recorders and attempt to recreate the events of the accident. This process can take weeks or months to complete.
Also Read | China plane crash: One black box found in severely damaged condition
