Here is a question for anyone familiar with Flight Data Recorders and their characteristics.
How common is it for a FDR to miss a complete cycle of readings, i.e. to miss all the sensor readings for one recording cycle? I notice that this happened with the China 747 CI611 aircraft about 30 sec before the FDR stopped for good and the a/c broke up. No other readings were missing from t/o to the end of the recording. The trace below was extracted from the FDR data published by the ASC in Taiwan.
I suppose a missing cycle could also be due to an error in the read-back system, or damage to the tape. But just considering the FDR alone, how common is this sort of thing. Would a missing cycle be considered symptomatic of a power system problem?
Also, no transponder signals were received for about 2 mins earlier in the flight. The transponder was not intermittently on, it snapped off for two minutes, and then snapped on again, and stayed on for the rest of the flight. This could also be e receiver fault. What could such intermittent operation be due to, and is it common?