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The flight data recorder (FDR) or Black Box is a flight data recorder used to record specific aircraft performance parameters that may help investigating aircraft mishaps. The FDR is also used to study air safety issues, material degradation, and jet engine performance. There are a large number of sensors located all over the aircraft that record parameters such as altitude, cabin pressure, speed, engine performance, hydraulic pressure, electrical systems, fuel etc. Modern boxes can record more than 700 parameters.The Black Box was invented in 1953 by Dr David Warren of the Aeronautical Research Laboratories in Melbourne, Australia and in production by 1957. In 1960, Australia was the first country to make flight recorders mandatory in aircraft.

A separate device is the cockpit voice recorder (CVR), which will record noises, such as cockpit warnings and conversations within the cockpit. There are several microphones in the cockpit that pick up conversations of the flight crew and other useful sounds such as alarms or sounds made when switches are moved. There may be up to four microphones in the plane's cockpit. Signals from these are sent to the cockpit voice recorder. Older voice recorder systems record sound onto a constantly running magnetic tape loop while newer systems use digital storage devices to hold much more voice data.

Some versions combine both devices in one unit. Although it is called "black box," aviation recorders are actually painted bright orange. This distinct color helps investigators to find out the black boxes following an accident. If the box gets submerged underwater (e.g. as in a sea crash), it automatically emits a locator signal once per second for 30 days. It is generally located at the rear end of the aircraft as this is the area most likely to survive a crash. Black boxes are designed to survive the severe physical conditions that occur during a crash.

The portion in the black box that contains information is protected with aluminium or titanium metal and insulated with thick layer of silica. This recorder can remain useable even 5000 pounds per square inch crushing force is applied. The data will remain intact even the boxes are placed in a fire (temperature of 2,000 degrees Fahrenheit or 1,100 Celsius) for an hour. These boxes are able to withstand submersion to cope with the crashes that end underwater.

After finding the black boxes, investigators take the recorders to a laboratory where they can unload data from the recorders and try to analyze the events of the accident. A team of experts consisting of representatives from the airline, airplane manufacturer and Government air safety agencies attempt to interpret the recordings stored on the cockpit voice recorder. A language specialist is often included. Experts will be able to analyze cockpit voice recordings for either the last 30 minutes of the flight or for up to two hours before it crashed depending on the model of the recorder.