What is the purpose of Black box in an airplane?

Updated: a day ago

When there is an airplane crash, who can help to explain the investigators what exactly happened?

  • Black box is a flight recorder which helps in the investigation of aviation accidents or incidents.

  • Black box is made up of two separate pieces of equipment,

Flight Data Recorder(FDR): Records flight details such as acceleration, altitude, airspeed, cabin temperature, outside temperature, flap settings, engine performance, etc., It can store up-to 25 hours of flight data.

Cockpit Voice Recorder(CVR): Records communication between the pilots, minor sounds like flipping switches, twiddling knobs inside the cockpit. Several microphones are built-in the cockpit and connected to CVR. It has the capacity to store recent 30 minutes of travel sound history. CVR stores information in loops where the old material is replaced when new material is recorded.

  • Data from both FDR and CVR are stored in Crash Survivable Memory Unit(CSMU).

  • CSMU is engineered to withstand extreme heat, tons of pressure, jarring crashes, salt water submerge.

  • CSMU components are mostly installed at the tail of the flight where the impact of a crash or an accident is less.

  • Black boxes are equipped with Underwater Locator Beacon(ULB). If the plane crashes into the water, ULB sends out a detectable ultrasonic pulse.

Although it is named "black box", it is actually painted in a distinct bright orange. Black boxes are invaluable tools for aviation industry. These lone survivors are responsible for cracking countless aircraft investigations.