dynamics

How does SSPRAM (solid state pre recorded announcements and music) work? is it equipped with a subsystem to detect phase of flight to automatically make appropriate announcement?

The mean time between failure of CSD which have been installed on specific airplane of model 737-300 was 14 days whereas the mean time between failure of another CSD with same P/N, installed on another airplane of model 737-300 with approximately the same Utilization (the same TFH/TFC) is 12 months??!!!! Do you have any idea on the reason for such a different level of reliability 

The problem is that mean time between failure of CSD which have been installed on specific airplane of model 737-300 was 14 days whereas the mean time between failure of another CSD with same P/N, installed on another airplane of model 737-300 with approximately the same Utilization (the same TFH/TFC) is 12 months??!!!!

What is SSPRAM?

I believe some failure modes of constant speed drive maybe attributed to unacceptable impedance of the supplied circuit

How can I measure the impedance of the circuit which is supplied by either generator 1 or generator 2 under full load condition?