Wuzhou, March 27 (BNA): Chinese authorities have recovered the second black box of a China Eastern Airlines plane that crashed into a mountainside last Monday, with 132 people on board, state media said.
The recovery of the flight data recorder (FDR) from the crash site follows the cockpit voice recorder (CVR) recovery process.
This is how the black box reading process works.
The black squares are not actually black but are high definition orange. Experts disagree on how the nickname originated, but it has become synonymous with searching for answers when planes crash.
Many historians attribute their invention to the Australian scientist David Warren in the 1950s. They are mandatory.
The goal is not to establish legal liability but to identify causes and help prevent accidents, according to Reuters.
Older devices recorded limited data on wires or chips. Modern uses solid state memory.
The recordings are placed inside crash survival containers that can withstand 3,400 times the force of gravity upon impact.
Both black box recordings recovered from the crash of the Ethiopian Airlines 737 Max in March 2019, like the East China plane, it covered the ground at a very high speed.
It weighs about 10 lbs (4.5 kg) and contains four main parts: a housing or interface designed to secure the device and facilitate recording and operation, an underwater positioning beacon, and a basic housing or “survivable memory module” made of stainless steel or titanium And inside there, the recordings are on chips or old formats.
There are two types of recorders: CVR for pilot and cockpit sounds, and FDR which captures information on parameters including altitude, airspeed, heading and engine thrust.
Technicians remove the protective material and carefully clean the connections to make sure they don’t accidentally erase the data. The audio or data file must be downloaded and copied.
The data itself means nothing at first. It must be decoded from raw files before converting to graphs.
Investigators sometimes use “spectral analysis” – a method for examining sounds that allows scientists to pick up on barely audible alarms or the first transient fault of an explosion.
Chinese accident investigator Mao Yanfeng said both the black boxes of the East China plane were manufactured by Honeywell, without naming the two models.
He said the CVR installed in the rear of the passenger compartment had a two- to three-hour recording time, with four channels including the captain and first officer, and one backup channel and one for ambient noise in the cockpit.
The East China plane crashed 66 minutes after takeoff.
Mao said the FDR at the back of the charging compartment has a 25-hour recording time, including about 1,000 data parameters.
CVR was first detected, and sent to an institute in Beijing for decoding.
Mao said the recording materials from the CVR apparently survived the accident and are in relatively good condition.
It may take 10 to 15 days for an initial analysis, and it may take longer before the final conclusion is presented in the report.
FDR will be sent to Beijing for checks.
Interim reports of crashes are posted after a month, but they are often sporadic. Deeper investigations take a year or more to complete.
Experts say that air accidents are usually caused by a combination of factors.
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