Launch HN: Airhart Aeronautics (YC S22) – A modern personal airplane • Hacker News Board

Re: Launch HN: Airhart Aeronautics (YC S22) – A modern personal airplane

#611

Post by joshvm » Wed, Aug 07, 2024, 11:48 AM UTC

nunodonato wrote: post #423

birdlogic wrote: post #322

Earlier quoted context omitted.

Yes! As a PPL that recently picked up gliding, I hugely recommend it. It’s a proper sport with a super high skill ceiling, supportive clubs, and competitions/racing when you’re ready. In studying for the glider rating, you’ll cover quite a bit that’s also applicable to flying “power”. Plus, the economics are great. I bought a glider earlier this year for about 15k. I recently flew 5 hours from a $50 aerotow to 2500ft…

isn't gliding more dangerous that GA? I've been wanting to try it, but the idea of not having an engine if you really need one, scares the crap out of me. Would love to fly in a motorized glider

In some sense yes, you learn a lot about energy management and you are acutely aware that you have no engine. On the other hand you always have no engine, so you learn to fly and manage your situation accordingly. At the more expensive end of the spectrum, some racing gliders have "get me home" mini props.

When you train, you initially fly in the vicinity of your home airfield and the risk is pretty low unless you do something stupid. For cross country, you train to do field landings and those are common enough in competition season. Basically you learn how to land out in situations where you can't sustain flight. You also tend to not fly over places that would make it difficult (eg built up areas or controlled airspace). Landing is always a decision made with plenty of time to spare, flown as a normal traffic pattern and usually starting the final glide with a lot of height. Competition pilots get more... close to the wire, but single seat gliders just want to stay airborne.

I don't know the accident rate proportionally, but glider related fatalities are extremely rare. In GA if you truly lose your engine, you have fewer options and you have to think a lot faster. While gliding you do also fly with a parachute, though there is scepticism about how effective it would be for a low altitude ditch.

Lots of pilots don't bother with cross country and just mess around their local airspace - still great fun.

Re: Launch HN: Airhart Aeronautics (YC S22) – A modern personal airplane

#612

Post by epolanski » Wed, Aug 07, 2024, 1:27 PM UTC

dartharva wrote: post #392

yard2010 wrote: post #372

Earlier quoted context omitted.

Only in the beginning and it's not linear. One track can be used by an infinite amount of people with very little to no congestion, unlike roads.

You also can't travel anytime you want. What happens when a doctor has to reach his hospital for a critical emergency but the next train is scheduled in half an hour?

He takes the car?

We're in a discussion about flights replacing 100/400 miles trips.

Re: Launch HN: Airhart Aeronautics (YC S22) – A modern personal airplane

#613

Post by entropie » Wed, Aug 07, 2024, 1:48 PM UTC

FabHK wrote: post #602

entropie wrote: post #600

Earlier quoted context omitted.

I think I did not. https://i.imgur.com/4Ik69ki.png

True. Next, don't forget that airplanes cover about 3x the distance as cars per hour. So, per mile they are on par with bad cars, and about 2x normal cars.

> Cruise Speed 148 KTAS is equivalent to approximately 170 mph or 275 km/h.

if the consumption is 7 times as high (very conservative calculation) and the speed is about twice as high, we are still at a modifier of 3.5. right?

Too much for me. We should be aiming for the absolute minimisation of fossil fuels.

Re: Launch HN: Airhart Aeronautics (YC S22) – A modern personal airplane

#614

Post by jki275 » Wed, Aug 07, 2024, 2:10 PM UTC

stetrain wrote: post #507

jki275 wrote: post #316

Earlier quoted context omitted.

Public transit exists in the US. I take a train to work. But the problem you're not understanding is that we're not Europe. We don't all live in cities within a couple of miles of our workplaces. Even me, I've got a sixty mile commute, I'm fortunate that there is a commuter train -- but I still have to drive five miles to get to the station. There's no other way, it's not even safe to walk if I felt like walking five…

The US used to have dirt roads and no highway system. It also used to have streetcar networks in most major cities and suburbs. And shops you could walk to from your house. Amsterdam used to have a city center full of cars, parking lots, and no bike paths. Things can change. It’s harder for them to change when we sit around and say “It’s just the way it is, it’s not going to change”

I think you're not really understanding the scope of the problem.

We have a train network. Amtrak is barely used, costs more than flying, and you still have to rent a car at the end of your multi-day trip on the train. The US is HUGE.

I lived in a mass transit society (Japan) for years. It's fundamentally different, in ways that aren't changeable.

Re: Launch HN: Airhart Aeronautics (YC S22) – A modern personal airplane

#615

Post by stetrain » Wed, Aug 07, 2024, 2:23 PM UTC

jki275 wrote: post #614

stetrain wrote: post #507

Earlier quoted context omitted.

The US used to have dirt roads and no highway system. It also used to have streetcar networks in most major cities and suburbs. And shops you could walk to from your house. Amsterdam used to have a city center full of cars, parking lots, and no bike paths. Things can change. It’s harder for them to change when we sit around and say “It’s just the way it is, it’s not going to change”

I think you're not really understanding the scope of the problem. We have a train network. Amtrak is barely used, costs more than flying, and you still have to rent a car at the end of your multi-day trip on the train. The US is HUGE. I lived in a mass transit society (Japan) for years. It's fundamentally different, in ways that aren't changeable.

I understand the scope of the problem. Saying nothing can change is also wrong.

We literally built a nationwide interstate highway system in this country which included bulldozing downtowns and spending the equivalent of hundreds of billions of dollars to do it. That wasn't that long ago, we're the same country in most ways.

It's a political problem at all levels. Not a technology or physics problem.

Looking at the full scope of the country and saying because the overall problem is large we can't take any steps to improve it is defeatist.

Re: Launch HN: Airhart Aeronautics (YC S22) – A modern personal airplane

#616

Post by FabHK » Wed, Aug 07, 2024, 5:32 PM UTC

entropie wrote: post #613

FabHK wrote: post #602

Earlier quoted context omitted.

True. Next, don't forget that airplanes cover about 3x the distance as cars per hour. So, per mile they are on par with bad cars, and about 2x normal cars.

> Cruise Speed 148 KTAS is equivalent to approximately 170 mph or 275 km/h. if the consumption is 7 times as high (very conservative calculation) and the speed is about twice as high, we are still at a modifier of 3.5. right? Too much for me. We should be aiming for the absolute minimisation of fossil fuels.

Speed is thrice, thus modifier = 2, or so.

Look, this is peanuts compared to everyday consumption by the world.

> We should be aiming for the absolute minimisation of fossil fuels.

Should we? We could easily do that. Just stop cars and busses and trains and planes and heating and the production of medicine and everything else.

Oh, our life would be much worse.

As a matter of fact, we should not aim for "the absolute minimisation of fossil fuels". Not at all. It is dispiriting for me to learn that you believe such primitive nonsense.

Seriously, you need to learn the basics of economics and trade-offs and all that.

Re: Launch HN: Airhart Aeronautics (YC S22) – A modern personal airplane

#617

Post by denton-scratch » Wed, Aug 07, 2024, 6:04 PM UTC

nikitaga wrote: post #380

TylerE wrote: post #212

Earlier quoted context omitted.

One key difference I see between something like this and an ultralight is the danger to people on the ground. A few thousand pounds moving at up to 200mph or so (potentially 300+ after structural failure) is a lot of kinetic energy.

Definitely not "key". On the ground fatalities are very rare, perhaps 1%-2% of all general aviation fatalities [1]. One massive restriction on ultralight airplanes is that you can't carry passengers. Again, on paper, because of risk, but it ends up having some controversial effects. If you want to occasionally carry passengers, as many pilots do, you can't fly a cheap, simple, light, and slow ultralight aircraft. No,…

> One massive restriction on ultralight airplanes is that you can't carry passengers. Again, on paper, because of risk, but it ends up having some controversial effects. If you want to occasionally carry passengers, as many pilots do, you can't fly a cheap, simple, light, and slow ultralight aircraft.

Ineresting. I get a ride as a passenger in an ultralight two-seater. The pilot was a Vietnam vet. It was in Virginia, and we overflew part of the Great Dismal Swamp, which has alligators.

Re: Launch HN: Airhart Aeronautics (YC S22) – A modern personal airplane

#618

Post by vdqtp3 » Wed, Aug 07, 2024, 10:41 PM UTC

callalex wrote: post #280

amluto wrote: post #275

Earlier quoted context omitted.

> I'm going to be calling my local government representatives to raise it back up by two with taxes and fees. Sometimes I think this sort of approach is why so many people on the right are sick of global warming. Sure, global warming is a serious problem, but that doesn't mean that taxing things you don't like is wise, fair, effective, or in any other respect a good idea. If you have a problem with emission of gasses…

Burning fossil fuels is the problem. We can argue until the cows come home about things like plastic straws and bags, but the fact is that burning fossil fuels is rapidly destroying the planet and no amount of burning is sustainable. Banning that is table stakes.

I'll take the "ban fossil fuels" comments seriously when nuclear energy is back on the table.

Re: Launch HN: Airhart Aeronautics (YC S22) – A modern personal airplane

#619

Post by vdqtp3 » Wed, Aug 07, 2024, 10:45 PM UTC

n_ermosh wrote: post #28

bronco21016 wrote: post #23

So basically a GA Airbus. I think this is a pretty cool project, and while it may not achieve the lofty goals you’ve set forth, any improvement in safety is worthwhile. As other commenters have point out though, where this stuff falls short is ultimately still the human. Ok, great… your aircraft won’t stall in Normal Law. However you’ve now lost a generator and a whole FCC and you’re in direct law. The 400 hr pilot h…

Thanks! you're totally correct that emergencies are where the real issues lie. That's why we've built in multiple layers of fault tolerance so that a generator failure or a flight computer failure doesn't immediately revert you to a direct law control scheme (I'm assuming you're familiar with Airbus control laws given that you're using those phrases) On top of everything, small GA aircraft have the luxury of being to…

> ones who haven't flown in 3 years and jump into a plane for an IFR cross country to an airport they've never been to before

So, pilots who aren't legal to fly?

Re: Launch HN: Airhart Aeronautics (YC S22) – A modern personal airplane

#620

Post by vdqtp3 » Wed, Aug 07, 2024, 10:54 PM UTC

n_ermosh wrote: post #542

dorfsmay wrote: post #324

Earlier quoted context omitted.

How do you make it easy to stay proficient? For example you say your plane will never stall, will your pilots train stall recognition and recovery regularly? How will prevent something like what happened to AF447?

We'll still encourage and require the same proficiency checks that pilots do today. Our hope is that GA pilots will no longer need to do things like train stall recovery. We are moving into an era of aviation where aircraft (not just airplanes) will be complicated enough that computers have to be in the loop to handle things like that, because it allows us to create more interesting aerodynamic aircraft that are more…

> Our hope is that GA pilots will no longer need to do things like train stall recovery.

I hate everything about this thought process. Every pilot should know how to handle stall recovery, for the same reason that every driver should know how to handle loss of traction whether they have traction control or not. Driving the skill bar to the bottom intentionally will just result in more and more people flying without a clue what they're doing, just like we have on the roads today.