>The inventor taught himself the basics of aeronautical engineering using YouTube and over two years built a single-seater helicopter using a car engine and scrap metal. I am speaking without enough knowledge. But I have to wonder if this serves as a harsh criticism of Youtube. I do understand Youtube is a mixed bag of resources. More structured learning might have resulted in better understanding of material strengt…
YouTube does occasionally take some of it down, but typically not until it's popular enough that it gets flagged by somebody that cares.