But we do know that NTSB investigations of accidents that occurred during a ten-year span beginning in 2012 cited powerplant failure as the principal cause of 2050 of those accidents, and further, that 214 of those accidents resulted in one or more fatalities.
Well, we started with 77 fatal accidents, then it was 214 fatals, now it's 2050 total. Maybe we should stretch the timeline back to 1903 to get some really startling figures to prove we must come up with better powerplants.
You did not address the Lycoming iE2 I posted, nor the SMA, nor the Austro. All modern designs. We "should" build better engines? Yeah, and we "should" stop all auto accidents by making cars totally idiot-proof, too. "Should" and "can" are two very different things, and we cannot now build far better engines and still be able to afford them. Lycoming sells very few iE2s and SMA's engines are rare indeed. The only one I ever encountered was the one I worked on. Even then, nice new designs like that will still fail if the pilot runs out of fuel, a common thing, or is too cheap to keep it maintained.
Here are some articles on the reasons for engine failure. You'll note that almost all are due to incompetence or stupidity on the part of the pilot, and I think we can admit that such pilots might be better off staying on the ground.
https://www.aviationsafetymagazine.com/features/why-engines-fail/
https://www.avweb.com/flight-safety/accidents-ntsb/why-engines-quit-failures-are-avoidable/
An excerpt from that second article:
Mechanical failure persistently accounts for about 15 percent of all crashes in general aviation, but not all mechanicals are engine related. Let’s put the standard risk metric on it. In 2016—the most recent year for which we have complete data— engine-related accidents amounted to 0.21 accidents per 100,000 flight hours, which is about 25 times lower than the overall accident rate. And considering that up to half of all engine failures are avoidable human-induced calamities, the risk could be even lower than that. But to avoid doing the stupid stuff, you have to know what the stupid stuff is and that’s what we’re covering here.
Engine failure accidents are 0.21 per 100,000 flight hours. That means, on average, you would have to fly 476,000 hours before you had an engine failure accident. I don.t think I could drive for half a million hours before my car quit for some reason.
That second article also pointed out that accidents often happen after engine failure due to pilot error in the forced landing. They'll often try to turn back to the runway, or try to stretch the glide to reach the airport to save the airplane, or get preoccupied with trying to restart the engine instead of flying the airplane all the way to the landing, whatever that landing looks like. Stalling and spinning in kills way more folks than crashing under control. Again, incompetence.
AOPA did a study maybe 20 years ago. The causes, in order of most common to least, looked like this:
1. Carburetor Ice
2. Fuel Starvation
3. Water in the fuel
4. Practice Forced landings (factors include cold engine, carb ice)
5. Oil starvation
Carb ice was, by far, the most common cause. NTSB often finds "nothing wrong" with an accident engine, and many of those engines are carbureted. Any ice that caused the failure is long gone by the time they get to the airplane, so they cannot blame carb ice, but they will say that "conditions at the time were conducing to carb icing."
Fuel injection systems fixed that long ago, but that system costs more money. Despite that, most new aircraft now are fuel-injected. Some legacy designs like the Aviat Husky, or the Citabrias, still sport carbs, to keep the airplane as affordable as possible. Anyone buying one needs to read the POH/AFM and learn from it and avoid the dumb failures. But so many won't do that.
Fuel starvation (or exhaustion) is just another dumb mistake. It happens way too often. Water in the fuel is inexcusable. Poor maintenance of fuel caps and a lack of diligent sumping is responsible for that. Most Mogas has ethanol in it now, and it absorbs water and takes it through the engine harmlessly. Before that, water often caused car trouble. Ethanol cannot be used in aircraft engines. They weren't designed to handle it, nor were their fuel systems.
Practice forced landings sometimes turn into the real thing. The POH/AFM is full of advice about that, yet it still happens.
People are lazy. Oil starvation is also another stupid thing. Failing to check the oil, or failing to maintain those oil hoses, does it.
Pilots have been dumbed down by all the automatic stuff in their cars, and so now they blame the old tech in the airplane for their problems. Somehow now it's the aircraft and engine manufacturers' fault. This is completely consistent with the attitude of current generations:
It's always someone else's fault.
I'm not a Luddite. I have been in aviation for 50 years. It has made me a realist. Commercial pilot, aircraft maintenance engineer. I have seen numerous attempts at new engines. I have watched the agonies that those folks go through, the vast amounts of money they spend on it. And I have watched flight training get weaker and weaker as young instructors pass on their ignorance to the students. The FIRST thing that needs to be addressed is pilot competence. Without that, they will find many ways to wreck the airplane. Period.
And the pitiful stuff I have found, as a mechanic, on airplanes owned by cheapskates has given me a real clear idea of what sorts of pilots crash when the engine quits.
If you know of a way to build a much better engine, show us. But I don't think you're an engineer or mechanic or homebuilder of engine conversions at all. It's real easy to criticize, much harder to offer workable solutions. This is not a new attitude; we encounter it regularly here and over on HBA. Building a better engine that doesn't cost far more than what we have has already been shown to be impossible.