Pilots and mechanics require guidance from the manufacturer in order to make safety judgments when conditions and anomalies occur, Inadequate guidance with which to fully assess the situation is a clear and present danger.
"The alternator was disassembled—found the ground brush (to be) 0.375 inches long. The field brush was completely disintegrated, with the spring contacting the slip ring. This alternator is only available from the manufacturer. There are no known third party overhaul facilities. The aircraft manufacturer service documents provide no service or parts data. There are no aircraft manufacturer inspection protocols beyond external security checks. Brush and/or slip ring inspection can only be accomplished by disassembly of the case. "I suggest a re-design to permit proper periodic inspection the brushes, make service and overhaul data available, and/or improve quality. Neither 'operation to failure' or 'periodic mandatory alternator replacement' is (acceptable)."
Not providing adequate and complete "Instructions for Continued Airworthiness" to maintenance assures that aircraft will remain in service with an inadequate level of safety.