Understanding the black box and why it can be so difficult to locate
The earlier days of black box technology well behind us, the magnetic tape recording medium has since been replaced by solid state memory to record data. Today, black boxes used on aircraft regulated by the Federal Aviation Administration has to meet some exacting specifications. FDR equipment must be able to record data for 25 hours consecutively and be able to withstand extreme conditions like impacts up to 3,400 Gs and fires lasting 30 minutes and reaching temperatures of 2,000°F. It can also resist water pressures at depths up to 20,000 feet. The CVR equipment must meet the same extreme condition specifications and record up to two hours of sound. Further, the black box equipment is mounted in the tail of the plane, which typically suffers last in an impact, giving the black box the best chance of survival.