“They’ll be lucky to get a viable data recorder out of that debris field.”
There are several tests that make up the crash-survival sequence:
•Crash impact - Researchers shoot the CSMU down an air cannon to create an impact of 3,400 Gs (1 G is the force of Earth’s gravity, which determines how much something weighs). At 3,400 Gs, the CSMU hits an aluminum honeycomb target at a force equal to 3,400 times its weight. This impact force is equal to or in excess of what a recorder might experience in an actual crash.
•Pin drop - To test the unit’s penetration resistance, researchers drop a 500-pound (227-kilogram) weight with a 0.25-inch (0.64-centimeter) steel pin protruding from the bottom onto the CSMU from a height of 10 feet (3 meters). This pin, with 500 pounds behind it, impacts the CSMU cylinder’s most vulnerable axis.
•Static crush - For five minutes, researchers apply 5,000 pounds per square-inch (psi) of crush force to each of the unit’s six major axis points.
•Fire test - Researchers place the unit into a propane-source fireball, cooking it using three burners. The unit sits inside the fire at 2,000 degrees Fahrenheit (1,100 Celsius) for one hour. The FAA requires that all solid-state recorders be able to survive at least one hour at this temperature.
•Deep-sea submersion - The CSMU is placed into a pressurized tank of salt water for 24 hours.
•Salt-water submersion - The CSMU must survive in a salt water tank for 30 days.
•Fluid immersion - Various CSMU components are placed into a variety of aviation fluids, including jet fuel, lubricants and fire-extinguisher chemicals.
http://science.howstuffworks.com/transport/flight/modern/black-box5.htm
Did they do the “ 100% grade granite rockface at 435 knts” test. I know that FDRs are rugged and the storage media is well protected, but that sudden stop could of well exceeded 3400g.