That would be a highly interesting evaluation. I worked in the Aerospace&#x2F;Defense industry in the 1980s, and it seemed to me that &quot;we can&#x27;t change X, X is &#x27;flight certified&#x27;&quot; was a huge excuse for not innovating, or maybe a huge roadblock to innovation. So it&#x27;s big news in 2016, when Boeing is hinting about stopping 747 production, an aircraft that made its first flight in February of 1969, 46 years before. I&#x27;m guessing that &quot;flight certification&quot; is the largest factor in keeping airliner technology in the 1960s.