> At some point airplane owners need to be forced to upgrade their engines, or quit flying. It's not about the owners, at all. Airplanes already have a limit o

> At some point airplane owners need to be forced to upgrade their engines, or quit flying. It's not about the owners, at all. Airplanes already have a limit on how many hours their engines have, after that it needs to be overhauled or replaced. It's just that, for many planes, there aren't really any options available, as other engines are not certified for their planes. Even for the planes that _are_ certified and can be changed to use other fuels, most airports don't have them available (even "mogas", which is automotive gasoline with no ethanol, is difficult to find).