Let the wreckage and the black box “talk”

  The passenger plane built with modern technology is a relatively safe means of transportation. This safety is full of the painstaking efforts and sweat of engineers. However, air crashes cannot be completely avoided, and they happen occasionally all over the world.
  When an air crash occurs, its investigation is a complex systematic project, which requires in-depth and comprehensive analysis from many aspects such as aircraft airworthiness maintenance, flight operations, air traffic control, weather and environment, and a large number of experiments if necessary. Validate assumptions. Air crash investigations sometimes last for a long time, as long as more than ten years, and there are not necessarily clear results. This type of investigation is generally carried out in parallel from three aspects: one is to find the black box, because it is a reliable data basis; the other is to investigate the scene, collect and organize all the wreckage at the crash site, and restore the relative orientation of the aircraft. The state of the accident at the moment”; the third is the peripheral investigation of the accident, such as investigating all personnel related to the accident, and obtaining all relevant information, archives and documents.
  No matter what geographical environment the plane crashed in, after the plane crash, the search and rescue team often searched for the black box in the wreckage of the plane for the first time. The black box is so crucial to solving the mystery of the air disaster that it is designed to be one of the strongest parts on the plane. Its storage unit can withstand high-speed shocks of more than 400 km/h, and can also withstand high temperatures of 1000 ° C for more than 1 hour. In many air accidents, the fuselage of the plane is often broken into pieces, while the black box remains intact.
  The black box consists of two parts, the flight data recorder (FDR) records flight data and some aircraft fault information; the cockpit voice recorder (CVR) records the sound in the cabin, as well as the communication between the crew and the air traffic control department. These two are important basis for judging the cause of the air crash, and their importance is self-evident. The FDR installed on Boeing 737NG series aircraft can record hundreds of thousands of flight data. It is recorded from the time the aircraft is powered on and ends when the aircraft is powered off, consistent with the CVR. Based on this data, investigators can roughly simulate the various readings and actions of the aircraft in flight.
  The wreckage of the plane could tell investigators more details. For example, sometimes there is a problem with the maintenance of the aircraft, and sometimes there is a problem with the design of the aircraft. After investigating the wreckage of the plane, investigators can determine when it fell off the plane based on its mass, aerodynamic characteristics and wind speed at the time of the incident.
  The investigation of an air crash should not only find out how the accident happened, but also check whether the same situation could have occurred on other planes in order to prevent the same accident. As the documentary “Havoc in the Sky” elaborates: “It’s not difficult to do any investigation and point the finger at a person, but we have to find out why the accident happened and how to prevent it from happening again.”