It's worth noting that all commercial aircraft that operate over water (so, the vast majority, excepting very small commercial aircraft and four-engine behemoths) have ETOPS ratings. [ETOPS, Extended-range Twin-engine Operations Performance Standards](https://en.wikipedia.org/wiki/ETOPS#:~:text=ETOPS%20(%2Fi%CB%90%CB%88t%C9%92,%2Dengine%2Dinoperative%20flight%20conditions.) specifies the amount of time the aircraft can operate on a single engine, measured in minutes. ETOPS-180 is a pretty common rating.

FAA is one of the better government agencies. In the US, they'd have to be tested and be shown to work on a regular basis in the same way that the emergency rafts and oxygen candles are tested.

It has nothing to do with website design. It's part of the HTTP protocol. A poor part in today's understanding and use cases, but in the 90s it would have made sense.

But why? There's no need for a PDF editor in a browser. This is just raising the size and lowering the performance of a browser for a feature that almost no one needs or wants.

Mozilla should probably build a PDF viewer/editor (Adobe sucks and Foxit has gone downhill in recent years), but it's not part of Firefox.