The National Transportation Safety Committee (NTSC) has announced that it has successfully downloaded the cockpit voice recorder (CVR) data conversation of the Sriwijaya Air SJ-182 aircraft.
The plane crashed in the waters of the Thousand Islands, Jakarta in January 2021.
Chairman of the investigation subcommittee of the National Transportation Safety Committee, Nurcahyo Utomo, said the contents of the recording of the Boeing 737-500, that crashed shortly after taking off from Soekarno-Hatta Airport, could not be disclosed to the public during the investigation.
Sriwijaya Air’s CVR was discovered at the end of March after a nearly three-month search in the waters of the Thousand Islands. One of the black boxes was found in mud that was sucked up by the dredger.
“We’ve got two hours of recorded conversations including flight conversations of the captain and co-pilot. NTSC has successfully downloaded all four channels from CVR, but channel four on CVR was interrupted,” said NTSC Chairman Soerjanto Tjahjono.
Each channel needs to be synchronised with each other, as well as radio communication, along with the flight data recorder (FDR) for analysis. This will help determine the cause of the Sriwijaya Air plane SJ-182 crash.
An initial report by the NTSC released in February said the Sriwijaya Air plane experienced an imbalance in engine thrust. The problem eventually caused it to roll sharply and then fall into the sea. The report included information from the FDR.
The black box is generally divided into two parts, namely the flight data recorder (FDR), and CVR which records all the sounds in the cockpit. Both are inseparable so that all potential causes of accidents can be analysed.
The FDR device records things such as airspeed and aircraft, altitude, movement of the aircraft wings, automatic pilot use, and fuel gauges. Meanwhile, the CVR records conversations on the flight deck and sounds such as radio transmissions and automatic alarms.
Basically, a black box is a means of storing conversations that occur in the cockpit, between the pilot and his crew or the airport control tower or air traffic control.