7. Inspections of flight recorder systems
7.1 Prior to the first flight of the day, the built-in test features for the flight recorders and flight data acquisition unit
(FDAU), when installed, shall be monitored by manual and/or automatic checks.
7.2 Annual inspections shall be carried out as follows:
a) an analysis of the recorded data from the flight recorders shall ensure that the recorder operates correctly for the
nominal duration of the recording;
b) the analysis of the FDR shall evaluate the quality of the recorded data to determine if the bit error rate (including those
errors introduced by recorder, the acquisition unit, the source of the data on the aeroplane and by the tools used to
extract the data from the recorder) is within acceptable limits and to determine the nature and distribution of the errors;
c) a complete flight from the FDR shall be examined in engineering units to evaluate the validity of all recorded
parameters. Particular attention shall be given to parameters from sensors dedicated to the FDR. Parameters taken
from the aircraft’s electrical bus system need not be checked if their serviceability can be detected by other aircraft
systems;
d) the readout facility shall have the necessary software to accurately convert the recorded values to engineering units
and to determine the status of discrete signals;