Comment by corodra | Hacker News Reader

Comment by corodra | Hacker News Reader

Flying cars have been functional since the 90s. There are more problems to this concept.

A. Imagine DUIs in widely available flying vehicles.

B. Autopilot is still dogshit. That's the truth.

C. If you're old enough, you'll remember when a commercial airline would be high in the sky and you'd still have to pause talking to someone on the ground. Now, even though they will be quieter, electric and all, but high speed rotors still make noise. Lots of it. Add lots of these in lower altitude. Good bye quiet spaces.

D. Maintaince. Oh my shit, few people properly maintain their ground cars. Wtf do you think is going to happen to a flying car? Difference is, you don't roll to a stop on engine failure. You crash into a home with someone's family in their teaching their toddler to walk.

E. You think those trucks through crowds were bad a while ago? This is borderline democratizing terrorism.

F. Mile per watt is going to be way worse than a car. Itll take way too much energy in comparison. Those power conglomerates are going to want their pound of flesh.

I remember C. Why did that stop? Are planes required to fly higher now, or did they get quieter?

High-bypass turbofans, or just turbofans in general.

In the early days of jet airliners, you had high-velocity exhaust providing all of the thrust. With turbofans, you have much more thrust coming from low-velocity bypass. This is quieter in itself, but also 'shrouds' the high-velocity exhaust.

As bypass ratios get higher, engines generally get more efficient and quieter. The challenge in doing this is mostly engineering the large fans.

Okay, then... am I crazy for noticing jet engines on airliners are significantly larger these days compared to 20 years ago? You did say larger fans. I always thought I was crazy when I noticed planes were quieter until Neil degrades Tyson mentioned it.

You’re not crazy. The engines are bigger and quieter.

Definitely not crazy, and the engines are getting larger. The 737 MAX issues stem the packaging issues of putting larger engines on an airframe that wasn't really designed for them.

The largest commercial jet engines are actually about as wide as the fuselage of the 737! The first jet engines were less than a meter wide.

Neil degrades Tyson talked about this on the Joe Rogan show. Jet engines became more efficient and were mandated to be quieter. I'm not sure about altitude because I live near a major airport. Always have lived near airports. The general noise is flat out less.

As far as E, not sure you could do more damage than a box truck would do. If you tried to fly into a crowd somehow you would crash and probably only hurt people within a relatively small radius.

Access to more crowds though. Imagine someone crashing into an Oktoberfest tent

Um... should I tell you about a little known event called 9/11?

Let's just add, oh, I don't know, 100 pounds of a fertilizer bomb like the Oklahoma city bomber. He used a lot more, but 100 is still crazy dangerous. Add you have a vehicle that laughes at bollards, gates and fences.

You do know, bad people actually do exist. Trusting tech companies and scifi hopes and dreams really isn't an effective strategy.

Which you can already do with existing small helicopters for rent, general aviation airplanes etc. Flying cars aren't a new threat in this respect.

Current pricing and registration are the current barriers to entry, especially training. It's not straightforward easy to fly a helicopter or small airplane. Not crazy difficult. But harder than a ground vehicle. Making it too easy and affordable and making them crazy plentiful in the air so they can't be tracked easily, that's the danger.

With big box cars, you can at least set up large concrete barricades to mitigate these on crowds.

With flying cars, you'd never be able to guarantee the safety of any outdoors event (and in either case, it doesn't have to be the result of terrorism, a drunk driver or a midair collision can still cause these problems)

I mean, anti air artillery. Lots of fiery death explosions and collateral damage. But we'll live in a world where the Gulf War air raids are the norm.

Bollards and concrete planters can stop a tractor-trailer going 60 mph. Dead stop. They are fully passive defenses. And minimum collateral damage.

Anti-air artillery is not a reasonable civilian defense system. It's just silly, not in any way relevant to the discussion at hand, and you know it. Stop trolling and move on.

Eh? I'm the one who did the ABC list. While yes, I'm in half jest, its partially serious. Because that's what will happen unless there are better safety alternatives.

How about remote shut off and control by a gov body? Too expensive and a wonderful vector for remote hacks.

FAA tracking and interception on deviated courses? Holy crap I doubt they can scale fast enough if buying and using flying cars "takes off". See what I did there? Also interception will lead to the same fire ball of death problem.

No fly airspace, which would become nearly every metro and suburb the same day. Thus making the flying car useless.

Unless we do SAMs or antiair, the flying car will be dead in the water. And still would be. It's too large of a premeditated and accidental disaster precursor.

If they're k12 rated. Most bollards are not k12, especially in cities due to shallow dig depths. Even if the bollard or planter themselves are k12. Normally they're never dug deep with supports because contractors are lazy assholes if you don't stand over their shoulder. And those that are k12 are expensive as shit. I actually work in protective design. That, and I think I'm funny so :P

Bollards and concrete planters are excellent for stopping a lot of mass going very fast, this is true.

One thing to keep in mind about the threat of "flying car attacks" is that weight requirements of staying in the air generally remove the "mass" part of the equation.

Someone could pack a flying vehicle full of explosives, but explosives that pack a big punch and that are compact & light weight are pretty regulated. Explosives that are easy to acquire tend to have more weight (fuel oil & fertilizer, for example). You could only pack so much in a vehicle before it couldn't take off anymore.

In general, I don't think flying cars would be any more of a risk than light aircraft, which have been around for decades without very many incidents of successful terrorism.

As an example, about a decade ago, and anti-tax nut flew a light aircraft into an office building that housed local IRS offices in Austin. It caused a lot of damage, but not serious structural damage and there were no fatalities other than the pilot.

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