The Home Run listening device on the flight deck utilizes the cockpit microphones that normally feed the Cockpit Voice Recorder (CVR), one of two black boxes armored to withstand heavy impact and thereby later give investigators significant clues to why the aircraft crashed. However, once hooked into Home Run, the CVRs are bypassed and voice transmissions are no longer recorded on the 30-minute endless loop recording tape. If Home Run is active for more than thirty minutes, there will therefore be no audible data on the Cockpit Voice Recorders.
No sensible engineer would have done it this way.
It is ALWAYS preferable to have as many redundant recordings as possible of an important event, and I would think that a hijacking is kind of important! Stopping the on-board recording is therefore completely stupid.
It also requires more electronics to cut off the feed to the CVR and switch it to the posited "Home Run" system, than to merely copy the signal.
This fact alone indicates the the writer of the article either knows incorrect facts about a real system and did not think about the design implications, or the system does not exist. |
