Comments elsewhere corroborate what I already understood - Convair 340 ZS-BRV has done little flying in the last nine years (since 2009), with its very infrequent trips aloft comprising mainly moves from Lanseria to Wonderboom to Freeway and back to Wonderboom again for ongoing storage. I'm by no means suggesting the accident flight was the aircraft's first in recent days nor am I casting aspersions on the quality of the maintenance it had been subjected to ahead of the proposed ferry flight to the Netherlands, but the reality is that old piston engines such as the R2800 sometimes 'let go' unpredictably when they have been largely dormant and not run at demanding power settings on a regular basis for long periods. It may be of course that the powerplants were not a factor (albeit that video evidences points to engine problems) or they were changed ahead of its ferry to the Netherlands, in which case this post is meaningless.