Sadeghi, a researcher of the project told ISNA "The FDR system is comprised of different parts including the recording system and the data-converting computer.”
"There are two types of recorder for aero planes. The first type is the protected one which resists difficult circumstances and stays unharmed after the crash. There is another system, the unprotected one with the same function as that of the protected type and installed parallel with it which cannot resist damages,” said he.
He added "Despite the FDR which takes a lot of time and effort to read, this type of recording system uses the stand-by system known as QAR.”
Sadeghi said the purpose for the parallel installation of the latter type of recorders with the FDR to be the convenience to check plane function and pilot behavior in each flight. "The DCVR and DFDR data are checked and analyzed after each flight so that mistakes are discovered and advices are given to the pilot,” he added.
He then pointed out that the cabin conversation and flight data recording are done digitally in this system and said "Previous recorders used tapes and then metal plates and they would encounter lots of problems. In this version we have utilized latest technology in which data are recorded on to a memory card with a much higher reading speed. It can read the data for 50 flight hours in 3 to 4 minutes.”