Editing Flight recorder (section)

=== Flight data recorder ===
{{Redirect|Flight data recorder|the song by +/-|Xs on Your Eyes}}
[[File:Black box.aeroplane.JPG|thumb|A typical flight recorder]]
[[File:Grossi-7.png|thumb|Cockpit voice recorder and flight data recorder, each with an [[underwater locator beacon]] on the front]]
[[File:Underwaterlocatorbeacon.JPG|thumb|An [[underwater locator beacon]]; the [[ballpoint pen]] provides scale]]
[[File:Two-In-One Data Recorder.JPG|thumb|A cockpit voice and data recorder (CVDR), with its attached ULB visible on the left side of the unit]]
[[File:Flightrecorders.JPG|thumb|A flight data recorder and a cockpit voice recorder installed on their mounting trays in the rear fuselage of an aircraft]]
[[File:东航MU5735班机第二部黑匣子寻获现场 Second Black box of crashed flight MU5735 retrieved 1.jpg|thumb|The flight data recorder for crashed flight [[MU5735]].]]
A flight data recorder (FDR; also ADR, for ''accident data recorder'') is an electronic device employed to record instructions sent to any electronic systems on an aircraft.

The data recorded by the FDR are used for [[accidents and incidents in aviation|accident and incident]] investigation. Due to their importance in investigating accidents, these [[ICAO]]-regulated devices are carefully engineered and constructed to withstand the force of a high speed impact and the heat of an intense fire. Contrary to the popular term "black box", the exterior of the FDR is coated with heat-resistant [[safety orange|bright orange]] paint for high visibility in wreckage, and the unit is usually mounted in the aircraft's [[empennage|tail section]], where it is more likely to survive a crash. Following an accident, the recovery of the FDR is usually a high priority for the investigating body, as analysis of the recorded parameters can often detect and identify causes or contributing factors.<ref name="TSO-C124b-3B"/>

Modern day FDRs receive inputs via specific data frames from the [[flight-data acquisition unit]]s. They record significant [[flight]] parameters, including the control and [[actuator]] positions, engine information and [[Timestamp|time of day]]. There are 88 parameters required as a minimum under current US federal regulations (only 29 were required until 2002), but some systems monitor many more variables. Generally each parameter is recorded a few times per [[second]], though some units store "bursts" of data at a much higher [[frequency]] if the data begin to change quickly. Most FDRs record approximately 17–25 hours of data in a continuous loop.{{citation needed|date=March 2014}} It is required by regulations that an FDR verification check (readout) is performed annually in order to verify that all mandatory parameters are recorded.{{citation needed|date=May 2015}} Many aircraft today are equipped with an "event" button in the cockpit that could be activated by the crew if an abnormality occurs in flight. Pushing the button places a signal on the recording, marking the time of the event.<ref>{{cite web|url=http://www.industrial-electronics.com/aircraft_18b.html|title=Aircraft Electronics + Electrical Systems: Flight data and cockpit voice recorders|website=industrial-electronics.com|publisher=A Measurement-Testing network|access-date=March 27, 2019|archive-date=November 11, 2018|archive-url=https://web.archive.org/web/20181111062649/http://www.industrial-electronics.com/aircraft_18b.html|url-status=live}}</ref>

Modern FDRs are typically double wrapped in strong [[corrosion]]-resistant [[stainless steel]] or [[titanium]], with high-temperature [[Thermal insulation|insulation]] inside. Modern FDRs are accompanied by an [[underwater locator beacon]] that emits an ultrasonic "ping" to aid in detection when submerged. These beacons operate for up to 30 days and are able to operate while immersed to a depth of up to {{convert|6000|m|ft|sp=us}}.<ref name="OSA"/><ref name="SSFDR" />