Investigation underway: A UPS cargo plane crashed shortly after taking off from the Louisville, Kentucky, airport Tuesday, leaving a fiery trail of destruction and a half- mile-long debris field. At least 12 people have died and others are injured, officials say, warning the death toll could climb as the investigation continues.
Black boxes recovered: An NTSB investigation team is on site at the crash location and has recovered the aircraft’s “black boxes” - the cockpit voice recorder and the flight data recorder.
https://www.cnn.com/us/live-news/ups-plane-crash-louisville-airport?ch=1
First, thanks for being curious. I’ll try to answer as best I can, but I am just a huge aviation nerd, so I’d welcome others to correct me if I misrepresent anything.
Could a quad jet run with only two engines, yes! But why? It would be the equivalent of you towing another car behind yours all the time, just in case the first broke. Not only are you putting more strain on the aircraft, but you’re hugely increasing drag and increasing your fuel and maintenance costs for very little benefit, so long as your primary vehicle is maintained appropriately.
Planes last 30-40+ years. Think if your next new car could last 40 years but it’s gas mileage doubled or tripled over your old car AND its maintenance costs went down by half. It’s not even a question to upgrade from a financial sense. That’s what the airlines see.
Next, can an engine be restarted cold? Yes, but it’s not like you’re just turning a key and away we go. Plus, during this startup phase, the pilots would still need to be actively troubleshooting the failed engine issue, so you’re only adding workload to the crew.
If I understand your comments overall, you’re uneasy with a twin jet because of engine reliability, and would like additional engine for safety, and that is an excellent suggestion. In practice, though, twin engines jets have their engine manufacturers to thank.
GE, Pratt and Whitney, and Rolls Royce (among others) have done amazing work to make these marvels run reliably. Old turbojets like on the 707 were low powered and relatively unreliable, which is why having 4 engines was done for safety. A modern turbofan can run for thousands upon thousands of hours with proper maintenance. And if one fails, the other is completely capable of powering the aircraft through all flight phases, from takeoff to cruise to landing.
Could there be a dual engine failure? Absolutely. But the odds are exceeding slim, and would almost certainly require outside influence. The latest planes have ETOPS 370 certification, which means that if one of the two engines fails, they can still fly on that single engine for six hours.
Imagine flying London to Los Angeles, and losing an engine over New York — they could just complete the flight and still be able to fly for over an hour. Not that they would, but just an example of the margins we’re talking about.
Twin engines are remarkably safe and reliable, and the data over the last 30 years backs it up. The longest flight in the world is done by a twin engine jet, for example. (JFK to Singapore.) In fact, of the top 20 longest routes, 18 are done by twin jets, and two by quads.
TL;DR: they’re safe, bro! Get on the plane and go somewhere fun! Sorry for writing a novel.