flight data recorder

A flight data recorder (FDR) is an instrument that records an aircraft's performance and condition during flight. These devices are required on commercial aircraft by regulatory agencies to aid in the analysis of crashes or unusual events.123

An FDR is part of a larger system, often referred to as a "flight recorder," which typically includes a cockpit voice recorder (CVR) as well. The FDR logs numerous variables, including airspeed, altitude, heading, vertical acceleration, and pitch, along with hundreds of individual instrument readings and internal environmental conditions.2

The data is stored digitally on crash-survivable memory units, designed to withstand extreme impacts, temperatures, and pressures. While commonly called "black boxes," these recorders are actually painted a bright vermilion color for visibility. The development of flight recorders began in the late 1930s, with significant advancements made during and after World War II, leading to mandatory installation on airliners by the 1960s.2