A Deployable Flight Incident Recorder Unit (DFIRU) is pictured in a posed photo at the DRS Technologies facilities in Carleton Place, Ontario January 21, 2015. Flight recorders or 'black boxes', used in investigations of aviation catastrophes since the mid-20th century, have developed considerably over the years. While older recorders contained spools of magnetic tape, modern devices use crash-survivable digital chips. There have been increasing calls for commercial planes to be fitted with ejectable recorders that separate from the tail during a crash, technology already in use by military aircraft. The 'deployable black boxes' combine voice and data recordings and emit a distress signal to a global search and rescue satellite system. Picture taken January 21, 2015 REUTERS/Chris Wattie