Originally Posted by
tdracer
...while the regulations may say a box can only be serviced by the manufacturer, the skills necessary are not particularly rare so as long as you're not worried about a western air-worthiness certificate, the capabilities to repair most of the black boxes is available.
It is not so much the skill set, but the data needed for the test bench setup that is lacking. These are all proprietary to manufacturers, and certainly not public. I'm sure the Russians have been actively trying to acquire some of these data, but I doubt they managed to get all. Of course reverse engineering is possible, but replication would require building up an entire industry food chain, not something that can be done overnight.