Originally Posted by
CPRich
I think it's best summed up in one part of his response.
Just about every airport on the planet is built in a certain way. Are you going to now train every pilot in 2 ways of doing something? Only have certain pilots that could land at this one/subset of airports? Rebuild every airport overnight?
The gasoline engine is far from the best solution for driving. Many better solutions have arisen over the decades. But the road/gas station/gas pipelines/regulatory/etc. infrastructure make it much, much more difficult than "let's just start throwing hydrogen fuel cells in every car" and everything is good.
I have a bigger problem with it--it makes you put the plane down at a much more precise point than a normal runway. If you have 10,000' of runway and need 6,000' that means you can put it down anywhere in the first 4,000'. With this you have a much narrower window and thus much less ability to land in bad conditions. It would also probably be basically unusable to low-time GA pilots.