There was a huge amount of lobbying in the 1970’s which says otherwise. The small Aircraft market is tiny and diverse as aircraft last a long time and many pas

There was a huge amount of lobbying in the 1970’s which says otherwise. The small Aircraft market is tiny and diverse as aircraft last a long time and many past manufacturers have failed. So, there wasn’t a viable alternative for many airplanes owners who couldn’t just swap to some other fuel or certified engine at the time. It’s been 50 years and people are still making the same arguments.