'Black box' definitions:

Definition of 'black box'

(from WordNet)
noun
Equipment that records information about the performance of an aircraft during flight

Definition of 'Black box'

From: GCIDE
  • Black box \Black" box`\ (bl[a^]k"b[o^]ks`), n.
  • 1. any electronic instrument or part of an instrument whose function is defined, but which is treated as a unit without consideration of the internal mechanisms; broadly, any device whose internal workings are considered as incomprehensible or mysterious by the user; as, to treat the meter as a black box and take its readings on faith. [PJC]
  • 2. (aviation) a device which maintains a record of cockpit conversations and the readings of many of the instruments on board an aircraft, continuously or at frequent time intervals during a flight. It is of rugged design to withstand a violent crash, and is used to determine the causes of aircraft accidents.
  • Note: They are often brightly colored to assist recovery, not actually black. [PJC]