SS has finally seen the point.
The NASA report was concerned only with design and manufacture reliability.
The figures would be somewhat different now with the recent Lycombing related fatalities, and grounding fiasco.
Like WC, these three problems I had were 'mechanics skill/procedure' related.
Definitely not covered by the report.
The fourth was magneto related, so could have been in either the manufacture/ design camp or the mechanics camp.
W C
Could you post how many hours per failure your experiences would average.