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Regional Air Mobility: Why we don’t plan to operate flights under 20km

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Re: Regional Air Mobility: Why we don’t plan to operate flights under 20km

#171

Post by MrFlynn »

microcolonel wrote: post #118
Gibbon1 wrote: post #90

Earlier quoted context omitted.

California is building a high speed rail line. But there is an enormous amount of reflexive opposition from NIMBY's, Conservatives, and Libertarians. To tell you how bad it is there are 100 year old train tunnels between New York and New Jersey that must be replaced and Republicans have killed the projects to replace them _twice_ simply because they are rail projects and passenger rail is 'bad'

> California is building a high speed rail line. Allegedly. > But there is an enormous amount of reflexive opposition from NIMBYs, Conservatives, and Libertarians. The greatest obstacles to California's high speed rail project are vote-buying politicians and the voters who do not pay attention or understand what they are doing. Conservatives and libertarians may have a lot to say about it, I gather that's because it…

> > California is building a high speed rail line.

> Allegedly.

Not allegedly, it's actually being built right now. 119 miles of it in fact. It's not the whole system, but it's the IOS that they promised that they would build.

> the target speeds are disappointing and there are so many detours from any meaningful corridor...

The target speed is 220 mph between Gilroy and Burbank which is in line with the current highest speed HSR systems in the world. The route actually makes a fair amount of sense given that the cities in the central valley are not that small, especially since the stations in those cities are designed for trains to express through them. Rather, it makes more sense compared to the I-5 corridor which would have required branch lines to be built, not to mention the other fundamental issues that proposal had.

Re: Regional Air Mobility: Why we don’t plan to operate flights under 20km

#172

Post by looping__lui »

hindsightbias wrote: post #131
GekkePrutser wrote: post #59

Earlier quoted context omitted.

Totally agree about the certification. It's so annoying having to do stuff like managing the mixture. There is absolutely no chance I'm going to be better at that than even the most basic FADEC system. Every car since the early 90s has done away with the choke, but for some reason in a 2020-built C172 I still have to do this... :X I would argue that this insistence on safety certification makes actual flights less sa…

Lycoming/clones with fuel injection, you typically only mess with mixture when starting and stoping them. There is of course a minority religious sect within GA who follow lean-of-peak theory and mess with their mixture constantly for better mileage (and possibly better wear, but that can go either way).

I can recommend Mike Busch on that topic (like somebody did earlier).

Leaning is not only for better mileage. The engines usually do not like a fat mixture for prolonged periods of time... I can’t recall all the reasons, but I think a couple of mayor ones were: 1) lead in the avgas will foul the spark plugs for rich mixture settings which is a safety risk, 2) exhaust gas temperatures will be lower which can lead to a build-up at the exhaust valves which can lead to wear and failure and 3) you end up with more dirt in your oil which makes engine corrosion even a bigger possibility...

Lean if you love your engine. And read Mike Busch - because he has the facts better than I do...

Re: Regional Air Mobility: Why we don’t plan to operate flights under 20km

#173

Post by AtlasBarfed »

praveen9920 wrote: post #38
Jabbles wrote: post #35

I would have thought any new transport technology would be heavily automated - from a brief look these require 1 pilot per 4 passengers. Not that it would be easy, I'm just surprised something so ambitious doesn't also include automation. At first glance I would have thought automating a small plane would be easier than automating a car - for one thing there are fewer things to crash into.

One word: compliance. FAA has lot of restrictions to allow a planes to fly with pilot in it. Imagine convincing them that without pilot.

You know that passenger planes basically can land with autopilot now?

Re: Regional Air Mobility: Why we don’t plan to operate flights under 20km

#174

Post by scarier »

chris_va wrote: post #66

Most people do not have the years to devote to becoming a good pilot, much less get a new category cert, so I find that these sorts of prototypes have a very limited audience. "Or maybe you want to escape to Lake Tahoe for a long weekend? That would be less than an hour on a Lilium Jet" ... ah, mountain flying with batteries, what could possibly go wrong. Also, I find the lack of a vertical stabilizer this plane to b…

Yeah, I worry that a lot of the use cases are in the most complicated and dangerous flight environments (mountains, big cities), even before you consider things like weather, airspace management, power margin at altitude...

>Also, I find the lack of a vertical stabilizer this plane to be an odd choice.

Not to mention any form of traditional aerodynamic control surface: "With 36 single-stage electric motors providing near-instantaneous thrust in almost any direction, control surfaces, such as rudders, ailerons or a tail, aren't required."

They've really doubled down on their VTOL shindig. Seems like a pretty big gamble making an aircraft that's entirely dependent on its propulsion system for basic aerodynamic stability and control (I'm also curious if the wings would make noticeably less lift in a glide). "Intrinsically simple design," huh?

Re: Regional Air Mobility: Why we don’t plan to operate flights under 20km

#175

Post by noir_lord »

xnyan wrote: post #112
noir_lord wrote: post #49

Earlier quoted context omitted.

I wonder what would happen if the car (or something similar had never been invented) and someone came out with a modern saloon today. "It'll revolutionise personal transport but we estimate it'll kill 40,0000 people in a horrible way per year" Like many things that are harmful in some way cars got grandfathered in (as did alcohol and tobacco) - if someone came out with an equivalent of alcohol with the same side effe…

>banned any drug with a set of side effects The word you are looking for is pleasure. The only types of drugs that are 100% illegal are drugs that have no purpose besides making you feel pleasurable sensations. Horrible side effects (e.g. chemo) and high chance of addiction (opioids, amphetamines, etc) and more are all allowed as long as the purpose of the effect of the drug is not (solely) pleasure. Alcohol, and inc…

I know we had problems with "Bath Salts" and Spice (synthetic marijuana) which was ironically legal at the time and but much worse than the original.

I've no dog in the fight, I think people should largely be able to put whatever they want in their bodies but I choose not to.

There is an argument about individual harm vs societal harm but good luck settling that one.

Re: Regional Air Mobility: Why we don’t plan to operate flights under 20km

#176

Post by AtlasBarfed »

wahern wrote: post #138
looping__lui wrote: post #57

Earlier quoted context omitted.

Unrealistic business plan estimations not factoring in the true costs of operating an aerial vehicle... It’s a bit like “soon to be plane owners” that don’t quite pay attention when they are told the spark plug for their Cessna is 50USD, they need 8 for 4 cylinders and replace them rather frequently ;-) Changes when they realize that those companies chartering out planes for less than 200 USD/h probably don’t make lo…

> It’s a bit like “soon to be plane owners” that don’t quite pay attention when they are told the spark plug for their Cessna is 50USD, they need 8 for 4 cylinders and replace them rather frequently ;-) That's supposed to be the promise of electric aircraft: almost all serviceable parts go out the window, just as with electric cars. Construction and maintenance costs are reduced to a fraction of what they are for mec…

Some israeli startup is doing replaceable aluminum air batteries. Also there are probably low-cycle solid state lithium designs that can start to approach the needed density, it would take a really good recycling loop though.

Re: Regional Air Mobility: Why we don’t plan to operate flights under 20km

#177

Post by runarberg »

renewiltord wrote: post #162
runarberg wrote: post #132

Earlier quoted context omitted.

True. This kind of technology would be a game changer for poorer rural communities with limited infrastructure and vast distances. Places like Greenland or East Congo. But this article did not mention this benefit at all. All they seem to care about is getting rich people between places they already can.

This is just basic marketing. You sell to the guy who can buy. The Tesla company was started in 2003 to productionize the AC tzero. In 2005, the Roadster was conceived as the product it became and Tesla and Lotus tied up. The Secret Master Plan arrived in 2006. So yeah, that's just how it goes. Because there is an army of people who lament things targeted at rich people, but that army does not participate in progress…

That makes the current state of our humanity kind of sad, doesn’t it.

It is also not true. There are numerous innovations targeted for the betterment of us all. The three-point seat-belt is a quick one that comes to mind. The field of medicine has tax funded research innovating at a remarkable frequency, where the target beneficiaries is all humans who need it. Expensive infrastructures like roads, train networks, electric grids, and trash disposal systems are build around the world for everyone who needs, not just the once who can afford it.

But we do lament things that are target at rich people, because these rich people are literally destroying the world with their over-consumption. They certainly don’t deserve more nice things that the rest of the world is paying for.

Re: Regional Air Mobility: Why we don’t plan to operate flights under 20km

#178

Post by looping__lui »

renewiltord wrote: post #151
looping__lui wrote: post #126

Earlier quoted context omitted.

Let me rephrase: The innovation you describe (which is cool and needs certification) bumped the price for a new airplane from about 50k in the 70s (I guess we may be talking 200k in today’s money) to close to 1MM USD. And that innovation is “just” glass cockpit, and some more advanced avionics. Not changing the principles - you fly a bit faster, a bit safer but still need a license and do all the preparation and chec…

You only pay the R&D costs once. All you're saying is that you have to put a lot into R&D, but that's all on the I side of ROI. It was the same with SpaceX, the I part was huge. The question is whether you can make the R part work. And if you have scale, then the R part moves differently. It's the same with the first car you build. The first Tesla Roadster cost tens of millions to make. The second Tesla Roadster cost…

I think we have different mindsets here: !every! company in aviation, the automotive or transportation industry is worried about the “I” for the R&D.

If there is a factor 10 whatever uncertainty in this equation - you are essentially just gambling like an Options-Day-Trader on Reddit. I understand that investors see “the hockeystick” unlimited revenue upside and justify everything around that.

But I personally would not want to so business in the most over-regulated, slow-growing and low-margin industry with a “factor 10 investment uncertainty”; that uncertainty btw renders your investment null, void and lost if your plane doesn’t get certified. And you don’t even have certification guidelines.

Re: Regional Air Mobility: Why we don’t plan to operate flights under 20km

#179

Post by nradov »

gibolt wrote: post #106
GekkePrutser wrote: post #85

Earlier quoted context omitted.

> e.g., each Cessna pilot has to make sure he has 30+min fuel reserve Well, this is pretty much standard practice! Edit: Ah I misunderstood your comment. So yes it is standard. However I could see this not applying to these guys, because with vertical landing capability they should be able to support field landings with really minimal risk.

VTOL and several other major capability differences really should change the certification process. Current certifications a designed around certain engineering constraints. Nearly all existing planes operate with the same basic parts, thanks to the fuel. This dictates the possible drivetrains. Reduced complexity can lead to drastic reconsideration. While I don't expect change to be super fast, regulation tends to mo…

There is already a certification process for helicopters and autogyros, so VTOL capability alone is no reason for a different certification process. Helicopters require a 20 minute fuel reserve in VFR conditions and 30 minutes in IFR conditions.

https://www.law.cornell.edu/cfr/text/14/91.151

Re: Regional Air Mobility: Why we don’t plan to operate flights under 20km

#180

Post by [deleted] »

barbegal wrote: post #153

I don’t quite see how you can spend only $10 million in capex and get 1 million passengers per year. With 4 passengers per flight that’s about 700 flights per day or about 1 flight per minute. That’s a lot compared to existing heliports that handle 50 or so flights per day. Even with a 15 minute turnaround time you will need parking space for at least 15 aircraft.

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