Why is AirAsia black box soaked in fresh water after salvage?

After the QZ850 black box was picked up from the Java Sea, they were immediately put in fresh water barrels to be taken to the Indonesian capital for analysis.

According to Airliners, after successfully recovering the black box of aircraft in particular and the electronic devices in general were soaked for a long time in seawater, people often immediately put them in fresh water barrels.This is a common process to curb metal corrosion, while diluting salt and other chemicals that come into contact with objects during the seabed.

So, after being salvaged from the Java Sea on January 12, the device recorded the flight data of the QZ8501 flight, the AirAsia plane crashed on December 28, killing all 162 people on board. Put in a transparent container containing fresh water to take from Pangkalan Bun search center on Borneo island to capital Jakarta.

The flight logger for QZ8501 flight was placed in a transparent container containing fresh water when arriving at the airport in Pangkalan Bun.(Photo: Channel News Asia)

If the plane's black box is left to dry naturally without intervention, its parts, from chips, electronic circuits to joints, capacitors . will start to corrode, leading to damage, in the worst case, is completely broken before moving to the laboratory to conduct analysis. Keeping the device in the water helps to delay the corrosion process because the amount of dissolved oxygen in the water is lower than the amount of oxygen in the air, so the oxidation process is slower.

Cockpit recording device (CVR) and flight data recording device (FDR) , two devices together called black boxes of aircraft, are water resistant but they are not always waterproof All, especially after the accidents, the protective cover of the black box is more likely to be pierced under the force of impact.

When the black box is delivered to the laboratory, experts here will take measures to ensure they are not further damaged. If the plane crashed into the sea and was submerged in water, similar to the case with AirAsia airline QZ8501 more than 2 weeks ago, they will be placed in the chiller to remain in the state. damp, prevent the black box from drying out, affecting the data recorded inside.

Experts will download data from two black boxes to recreate the situation and conditions on the plane when an accident occurs. This process usually takes several weeks or months to complete. However, it may only take a few minutes to read the necessary data if the black box status is good. Black box manufacturers often provide investigators with a black box reading system and the necessary software to analyze data taken from them.

Both cockpit recording and flight data are invaluable for the investigation of the cause of aircraft accidents. This is often the only thing that survives in every tragedy and provides an important clue to investigators, so preservation should be focused on the smallest detail.