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Comment by bmcusick | Hacker News Reader

It was 13 years from the Wright Flyer to the first commercial fixed-wing aircraft. And that was still very dangerous. Jet engines (which really introduced the safety we are used to in airlines) took 50 years.

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Jet travel brings improved speed and comfort, not really improved safety. Prop planes, as a technology, are very safe. It is a lot easier to land a prop with a failed engine or another part -- due to is low speed one can land small props with a high chance of no injuries on unprepared surfaces such as grass fields. For jets, if you have a failed engine and no landing strip you are likely toast (although there are some well publicized exceptions).

The great flight safety numbers of modern jet travel are due to the fact that commercial traffic is heavily regulated end to end, from production to operation, licensing and maintenance. None of this is specific to jet travel, it is just that speed and comfort pushed props mostly out of the business.

It is very counter-intuitive, but speed increases safety in an aircraft type both as a function of hours and as a function of miles. This is an empirical fact that's true for both military and civilian aircraft, I was looking for the US Air Force chart on this, but couldn't seem to find it. Not to discount other factors, but the OP is correct that speed increases safety. Maybe someone with more Google skills can find this chart.

Speed + altitude combine to give you options, options are what makes an in-flight issue survivable.

What you describe has nothing to do with jet versus prop, it's just big versus small. Small planes can land in small, unprepared fields, which are common in many parts of the world, whereas large planes can't. You could make a small jet-powered Cessna that would be just as capable of landing in such small places, while offering more safety due to better reliability of the engine. And an airliner-sized prop plane would be no more capable of landing in a hayfield than a 737 would be.

Sure, big vs small is a better way to slice it. In fact fast vs slow is likely a better distinction still. But jets are more practical for fast(er) planes.

You're not really looking at an apples to apples comparison. The last generation of piston engine airliners (the only ones really comparable to the jets that replaced them) used massive turbocharged radial engines that were notoriously complex and unreliable because of all the power being squeezed out of them. Today the vast majority of "prop planes" used in commercial airlines are actually turboprops. Piston engines are basically relegated to small private planes.

Why do you say that jet engines introduced safety? If anything, jet engines were very unsafe for a long time. I would argue better manufacturing, redundant parts, better flight training, and quality assurance that led to the safety I expect when flying today.

Every screw on a Boeing aircraft has a documented specification for the torque used to install it. That’s why I feel comfortable to fly as much as I do.

Pre-Jet flight wasn't exactly a suicide run. A turboprop plane with dual engines was as safe as a jet, fixed for a number of factors.

The larger benefit with jets is being able to fly much higher and faster and being able to hit the 30,000-35,000 sweet spot where the air is thinner, the plane is above storms, and jet fuel efficiency for typical planes is pretty good. The larger 'innovation' on the success of jets is the lowered cost per seat. Props at 10k altitude burned a lot of fuel and were slow which hurt their ability to get more fares. Safety didn't hold back the industry. Cost and speed did.

edit: applies to non-turbo prop as well

Turboprops were developed after jets.

But yeah there were other reasons planes got much safer after around the 1950s.

In fact, turboprop (and turboshaft which is the same thing, but for applications other than fixed-wing aircraft propulsion) is jet engine designed such that it produces mainly mechanical power instead of thrust.

Most commercial airliners use turbofans which are similar in that majority of their thrust does not come from the engine's jet exhaust.

Turboprops were developed in the 20's

https://en.wikipedia.org/wiki/Turboprop#History

and used in popular prop airliners like the Lockheed Electra:

https://en.wikipedia.org/wiki/Lockheed_L-188_Electra

I'm guessing you're thinking of turbofans.

The Electra flew after the Comet.

and the DC-3 and Boeing 247 and 307 before the Comet.

I don't know why you're arguing we had jet airliners before propliners. In general, props greatly predate jetliners for civil aviation.

The DC-3 wasn't (originally) a turboprop.

Wright were 1903 and first jet was 1938 I thought. Are you meaning that it was 50 years before jet engines commercial flight?

This analogy can't work in 21st century. First this is linear thinking, it does not take exponential progress into account. Second, in the case of Autonomous vehicles, the problem is purely software related and does not have any limitations in terms of hardware.

>does not have any limitations in terms of hardware.

That seems a little strong. Lidar tech, for example, seems to still be a differentiator between competitors.

Good observation. Compounding progress in other sensors (high-resolution stereo cameras, GPS, radar/proximity) has also been important, but none more so than lidar. Also, increased on-board processing power for computer vision/machine learning. In the early 2000s we had nowhere near the onboard compute that we have now.

The problems are more than hardware and software.

Hardware and software is designed against ethical, legal and liability standards. This is illustrated by the high number of rear end collisions that robot cars are prone to vs human drivers.

Experience in the field doesn’t happen exponentially. Development of law relating to these matters doesn’t happen exponentially.

I don't know, it looks like it's holding true so far. If it was 13 years from the Wright brothers to the first commercial flight and now we're seeing 10 years from the "Wright brothers" of self driving cars to so far not having a commercial product.

Why do you think we are experiencing exponential progress in the area of self driving cars? Why do you think that the Wright brothers era weren't experiencing exponential progress with respect to the technology they needed to make commercial flight?

Finally, with hardware we normally only have to worry with 3 dimensions plus time. I guess fluid dynamics is kind of complicated, but we can at least put the thing into a wind tunnel. With software things can get more complicated because they're not constrained by physics anymore. But at least we have debuggers. With self driving cars we're going to have a support vector machine or a neuro net or something like that running. Some of these techniques can't even be debugged ... they just work or they dont. I'm not sure being free of the limitations of hardware is an asset.

You can debug AI's by putting them in simulators and running them through many scenarios. What Google does.

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