You're *assuming*, aren't you, that this was the result

of a _single_ failure?  Could have been a whole bunch of

things went to &#^!, and the "failsafe" failed, too.

 

Dale R.

 

It may semantics; but I’d say if everything went out at once, with no ability to retrieve power, then, by definition, that was a ‘single point’ failure.  It may not have been apparent on the schematic.

 

Al