Variables collected by these devices might include the (*) DC bus status.  
Krishna M. Kavi argued that these things should be replaced with a "glass" alternative stored in the cloud and powered by Ku-band technology.  The largest manufacturer of these devices, Florida's L-3, assures buyers that theirs are C121b compliant.  Some of the first of these devices were named HB for co-inventors Francois Hussenot and Paul Beaudouin and used photographic film as a medium.  Later devices of this type were called the Red Egg.  In the 1960s, the Australian government became the first to mandate the use of these things. Variables collected by these devices might include the (*) DC bus status.  EUROCAE ED-112 requires that they be heat resistant up to 1,000 degrees Celsius.  Many of these devices can send ultrasound signals for 30 days. They're often colored orange. For 10 points, name these devices which might capture cockpit audio and are designed to survive plane crashes.
Krishna M. Kavi argued that these things should be replaced with a "glass" alternative stored in the cloud and powered by Ku-band technology.  
airplane black box [or flight data recorder; or FDR; or CVR; accept cockpit voice recorder before "audio" is mentioned] 