SureFly – a personal helicopter designed for safe and easy flight | Hacker News Reader

SureFly – a personal helicopter designed for safe and easy flight

workhorse.com

147 pointsprostoalex152 comments

A part of me thinks this is really cool tech and it would be amazing for anyone to be able to just hop aboard their personal helicopter and fly wherever they want, but then another part of me thinks of the future this would create, skies no longer clear, filled with objects buzzing around and what hell that would be, on top of the already stressful and crazy life we have now.

It's the kind of situation where I think I'd actually rather the tech never exist.

This would have to fall into the ultralight classification for someone to fly this without training. The FAA could easily classify this otherwise if they perceived any problem.

Also, getting your pilots license is nothing like getting a car license, the training is much harder and requires a certain amount of hours in the car with a licensed flight instructor before they can fly on their own (I believe it's 50 hours in the cockpit). It's also prohibitively expensive as you have to pay for fuel and time. You won't see a bunch of unmotivated teens flying these things any time soon. Having worked at the FAA on the regulation side of things, I can also tell you if that did become a problem airspace and licensing would change.

Its way to heavy to fly as an ultralight under Part 103, which has a 254 lb maximum dry weight. Its probably too heavy to fly as a light sport, which has a 1,200 lb max gross weight limit, compared to the SureFly's 1,500 lb max gross weight; if you derated the max gross to make it LSA legal, then you'd only have a useful load of 100 lb, including fuel.

You can get a private pilot's license with 40 hours total time. (Most people do it in around 60-80.) I don't have as good a feeling on the stats on time until solo, but the average is almost surely under 20 hours.

Agree that this isn't going to be a hobby for the average unmotivated teen.

I share this concern, and it will probably be awful in the beginning. However, that being said, I thought i'd hate living next to an airport, and I live by one right now. The sounds of planes over my head are often ignored and I enjoy looking up and seeing a plane coming in for a landing. So what I thought I would hate I actually grew to enjoy. People adapt, that's actually what we're really good at.

An average plane carries around 150 to 200 people and planes are used only for long distances. Living in a world where the affordability of these are like cars, would be far worse, I imagine.

Unlike cars, these machines would not be tightly packed into roads, concentrating the noise and pollution; likely they'd have to keep a serious distance.

Also, with a top speed of 70 mph and range of 70 miles, it does not look like a great daily-commuter vehicle. This device looks like a good fit for an expensive urban fast-jump service, or a good solution for places where roads are hard to build, like going to a forest hike or a mountain trip.

If you're outside 70 miles, you've got bigger problems. But considering that rush-hour traffic can bring average freeway speeds down to the 5 and 10 MPH range, I'd say this would be a huge improvement for daily commuting. At great expense of course.

The only thing is, something invented for a niche market on Sunday will be made much cheaper on Monday, will be widespread and causing mayhem by Tuesday, regulated to the hilt on Wednesday, the sole domain of big corporations by Thursday, and used for aerial assassinations at-will by the military by Friday.

(My little sequence there takes a cue from this talk, posted on HN yesterday: https://news.ycombinator.com/item?id=16106331 )

70 miles one way, so it's likely 35 miles round-trip after which you're dry.

Winged aircraft is so much more economical, but it's necessarily large.

Curses, foiled by the old "one way/round trip" trick!

I think there are a lot of places (SF, Los Angeles) where if you could travel 25 miles at a consistent 50 MPH speed that would be a huge improvement over many people's commute. It would be great for my commute personally. I can see reasons why this would not work as a commuter vehicle, but speed and range don't seem to be the issue.

70 miles by air is a long distance. You really want ~1 hour of reserve in an aircraft, but it said 70 miles per tank so you might have 70 miles with a 70 mile reserve.

Remember weight is the real limit. So, having a single passenger frees up ~150 lb for extra fuel.

I wouldn't worry about that. Most people can't even drive cars in "2D" safely, never mind helicopters. The general public will never be given the skies, unless the flights are automated.

It's much harder to hit something in the air.

As any pilot knows, the stomach unfriendly words from Tower are: "Caution, Wake Turbulence".

The air, being a sparse fluid, can change fast. Especially so if another aircraft has flown through it recently. It's not that there isn't anyone there, it's the air they left behind is all non-laminar now. Doubly being suddenly downwind of stationary objects like towers, wind farms, and mountains.

Also, quick point of caution: One reason early flyers died a lot because they flew so low. Even after a few meters of height, just about any crash is likely to be deadly. Paradoxically, the higher you fly, the better off you are (in certain cases). In flying, your height can be measured in 'mistake recovery time'. The higher you are, the more time you have before you hit the ground, the more time you have to fix a mistake. If your engine cuts out, you have a longer glide time to look for a lake. You can get a fuel pump restarted or unfrozen. You have more time to grab a parachute and bail. Etc. It took a long time and a lot of lives to realize this. As such, personal drone-choppers will be more dangerous and I fear we will have to re-learn the lesson of height being a friend in aviation.

It comes with a parachute

If anything, that makes it more dangerous. Besides a sense of 'false' security, chutes do take a certain amount of height to catch air and become safe. IIRC it's about 100m and turbulence will affect that in strange ways.

In the end, I still fear tech like this will not be as stringent as needed.

Which doesn't help at all when you hit wake on final. Chutes take a surprisingly long time to grab the air and slow you down.

But much easier to hit something on the ground (powerlines, houses, highways).

It's much easier to be cocky and negligent if the last 100 times you drove you never encountered something to hit.

Don't today's drones and airplanes demonstrate that automating flying is a lot easier than automating driving?

I work in the field. Basically, yes. On average it is easier to fly than it is to drive, mostly because there's far fewer things to crash into. But on the other hand, almost any failure can become catastrophic - falling out of the sky will usually have much worse consequences than, say, bumping into the car in front of you.

That might stop being true if the air is as crowded as the roads.

As long as they're all outfitted with transponders, and piloting is automated, I don't see that being an issue.

The air won't have pedestrians and bikes!

Para/hang-gliders, small drones, birds. There's plenty of stuff you don't want to hit :-)

Cue legislation to make kites, balloons and RC aircraft illegal

No they don't. Drones are generally only allowed to fly at very low altitude in most US airspace because they can't reliably see and avoid manned aircraft operating under VFR.

True. But there is a reason pilots are still a requirement.

I empathize but I think that attitude is an artifact of the age we grew up in. I'm sure equestrians felt the same way when those rackety automobile contraptions started zooming around.

I think everyone must have felt this way about automobiles. And by and large, it's worked out just as horribly as they imagined: our communities are divided by dangerous moats we call "roads" -- death traps which we must painstakingly teach our children to avoid, if we dare let our children wander outside on their own anywhere near them in the first place.

"more deaths per capita in horse accidents in NYC in 1900 than in auto accidents today"

https://legallysociable.com/2012/09/07/figures-more-deaths-p...

I don't get the point - are you suggesting we'd be better off without automobiles? Would we go back to horses? What about global logistics? Agriculture?

We'd be better off with dense cities where automobile is not the primary means of transportation. Like e.g. NYC or many European cities.

Cars and large trucks should mostly belong to highways and country roads.

NYC is a very far way from being a carless paradise. Yes, lots of people walk or take transit. But, especially in Manhattan, many streets are choked for a good chunk of the day.

Far more people use the subway than drive to work.

Only 28% of people in NYC commute by car/truck/van. 55% take public transit and 10% walk, 1% bike, 4% work from home, and 2% take a Taxi or other. https://www.nycedc.com/blog-entry/new-york-commute

PS: The van thing is also closer to a bus than a private car.

It's not a paradise, but it's a city where you can live nicely without a car, and without a slightest desire to own it. Public transportation (non-ideal as it is) and the occasional uber / lyft / cab trip cover the needs of daily commute. Also, walking is easy, and a lot of things are within an easy walking distance, not only on Manhattan but also in most of Brooklyn and Queens.

I live in a major city (Toronto) and don't own a car, but this is still something of a fantasy - major cities are incredibly reliant on automobiles for moving goods in and out of the city even before you consider moving people.

And with that said, Toronto is far from being a city where we could live without cars for human transportation - without Uber getting around would be hell.

Cars as a secondary transport are fine. In NYC I take a cab / lyft once in a while, but it's like 3% of my trips.

Delivery trucks are, or course, incredibly important in a city. But they are also much more efficient than cars moving 1-2 people, so they need a bit less road capacity.

Also, city traffic is pretty favorable for electric vehicles with recuperative braking, so the coming crop of city buses and delivery trucks is going to have a significant portion of all-electric or hybrid vehicles. This helps the air pollution problem.

Very much a personal opinion. I hate living in dense cites. Dealing with owning a car in the city makes it worse, but I prefer living in a less dense area and owning a car. In fact I own 5.

Not having to drive a car daily is freedom. Living in a city with functioning and affordable public transport is, well, a blessing of sorts.

I didn't read the comment as a suggestion of being better off without automobiles - merely an observation that the same reservations were felt by people transitioning from horses to automobiles...

It's not a binary choice between "current system" and "no cars whatsoever".

We might not be better off, but the rest of the planet sure as hell would be. Not to mention that the history of overpopulation would be very different without those things.

>I think everyone must have felt this way about automobiles. And by and large, it's worked out just as horribly as they imagined: our communities are divided by dangerous moats we call "roads" -- death traps which we must painstakingly teach our children to avoid, if we dare let our children wander outside on their own anywhere near them in the first place.

Yep, JFYI, an excerpt from "Autophobia":

http://www.press.uchicago.edu/Misc/Chicago/467412.html

Those rackety automobile contraptions! Don't get me started! :)

I am half serious though, cars are annoyingly loud and (obviously) dangerous. I'm loving the eerily quiet electric vehicles. And cities creating carless areas of town or carless days.

I don't know. Just because I haven't been exposed to it yet and it's not the new normal doesn't necessarily mean it's an objectively better world.

And speaking of automobiles, I feel like a lot of cities are actually fighting back against that now, creating pedestrian-only areas etc... I like the autonomy and mobility that cars offer as much as anyone else, but I sure do enjoy the peace of a quieter country side, and I'm afraid with this technology, even that would go away: there would be no place left to escape the madness.

In my opinion, progress is what makes the world a better place overall for humans, as in better quality of life, not what makes the world a shinier place with new toys, even though we might be getting better and better at creating those.

At the end of the day, the cons far outweigh the pros here for me.

I still feel that way about cars. Those horse riders were right.

On the other hand think about the positives: all the terrestrial traffic and distributed refueling and service infrastructure that might no longer be needed; it would revolutionize everything from personal transportation to shipping and logistics. And yeah it would require a vastly enhanced and much more autonomous traffic control system.

These helicopters still require refueling. In fact they're generally going to be less fuel efficient than passenger cars, even after accounting for traffic delays and routing.

If we can have self driving cars, sure these can be self flying then you don't have to worry.

With your AR eye glasses and earbuds, it can clean out the clutter showing you a clear blue sky and eliminate all the buzzing.

I wouldn't worry. Most people can't afford $200K cars that burn an entire tank of gas an hour.

I'm very skeptical of their claims of "unparalleled safety". Thanks to "autorotation"[1] regular helicopters can safely land in most situations even with complete power failure. The claims of safety of this craft seems to derive from N+1 battery redundancy which isn't that impressive. They say they have 8 independent motors, but don't say how many are needed to stay aloft.

[1] https://en.wikipedia.org/wiki/Autorotation

Small "personal" helicopters like the Robinson R22 are quite difficult to autorotate safely in a real emergency, due to low rotor inertia. [0]

For the SureFly, Hypothetically if loss of several motors caused the aircraft to be unable to maintain altitude, the aircraft would not suddenly drop like a brick, but drift down to a controlled landing.

[0] http://philip.greenspun.com/flying/robinson-r22

No, worse. That thing would turn into the tumble dryer from hell with partial power. It has no blade pitch control (like a helicopter does), requiring power on the motors in all four corners to maintain stability.

The real emergency situation to worry about would be a total power failure. Failure of the individual electric motors will likely be extremely rare but a battery fire or controller failure could send this thing falling like a rock due to the lack of auto-rotation. It has a BRS chute but that won't do anything in the critical ~500ft band above ground level, too low to deploy normally. Additionally, I hope they've figured out how to guarantee safe chute deployment while inverted because of the tendency to tumble with no/partial power.

BRS parachutes have been tested as low as 260' AGL at 187 knots (several times faster than this craft would ever go) and individuals have reported successful deployments below 100' AGL[0] The question of course is how quickly it can be deployed in this craft as the vertical speed will likely be much faster than a Cessna or Cirrus in the event of total power failure.

[0] https://www.flyingmag.com/g00/how-it-works-brs-aircraft-para...

I can't imagine an inverted deployment at 100' would end well...

For a drogue-deployed parachute, horizontal speed helps, as the required travel through the air is accomplished faster, and therefore with less drop. BRS parachutes use a rocket to fully extend the lines, but there is still the matter of inflating the canopy.

> For the SureFly, Hypothetically if loss of several motors caused the aircraft to be unable to maintain altitude, the aircraft would not suddenly drop like a brick, but drift down to a controlled landing.

Source? I'd think loss of two stacked rotors would lead to loss of control, tumble, and dropping like a brick (until BRS deployed), not controlled descent and landing.

there's a parachute

that's what I mean by BRS deployment.

https://en.wikipedia.org/wiki/Ballistic_Recovery_Systems

my mistake. thanks for the link

Robinsons in general have this problem (among others, such as their tendency to disassemble their own rotor systems in flight, and their incredibly awkward t-bar cyclic controls), but I'd still rather take my chances with a Robinson autorotation than rely on a ballistic parachute system.

That said, I would never willingly fly this thing or a Robinson, so I guess I'll never have to deal with either situation.

Electric motors are less complicated and more reliable than piston engines (as in small helicopters), I'd say (not sure about turbines). And then there's the ballistic parachute rescue system, though of course there's a minimum altitude you need for that.

The Volocopter (a competing concept that actually exists and has had manned flights since 2016) has 18 rotors (six arms with 3 rotors each in a single plane), opposite rotors driven by the same battery/drivetrain ensemble, from what I gather, and remains controllable with up to 3 rotors (at least) faulty.

I'd hope well engineered aircraft of this sort will surpass safety of traditional helicopters, but let's see.

Yet even with autorotation, helicopters are somewhere between 27 and 85 times more dangerous than cars (depending on your methodology) [1].

[1] http://www.slate.com/articles/news_and_politics/explainer/20...

They got a parachute, and with a rotor layout like this, attaching a parachute safely is pretty simple.

Going down on a parachute is not exactly comfortable, but at least you're not going to crash at the earth like a falling rock. It turns a catastrophic crash into an unpleasant but likely quite safe collision.

Could it be because autorotation requires a skillful, vigilant pilot, and the redundant systems of this machine help avoid urgent need for it?

Autorotation is often taught after only 8 hours of training. It is very feasible to have an AFCS that will do an autorotation, but it is harder to find a place to land.

There’s also a parachute.

Should be four or less considering each arm has two props. (Unless the motors aren’t powerful enough)

A lift/weight ratio of 2:1 would be quite remarkable, and the ceiling of a mere 4000' suggests that it does not have that sort of reserve, even at sea level and when being powered by the gasoline motor. Being anywhere somewhat hot or high would quickly erode that margin.

On the other hand, the chances of four motors failing in the time it takes to set down is probably not high. Back to the first hand, if you do have multiple failures, it is not likely to be an optimal grouping.

If all four on one side went out, I assume you'd be in big trouble.

I'd imagine if two stacked ones go out, you'd be in trouble (as the centre of gravity will not be exactly in the intersection of the two diagonals).

Actually that's a benefit of the quad-copter design. It can sacrifice an axis of control in that situation (a "minor" one, like rotation about the gravity vector). In this case it would likely make the passengers sick, but it would still be able to fly in a controllable fashion.

See this video: https://www.youtube.com/watch?v=ek0FrCaogcs

with the counter-set props probably less spin even

Yes, you go from 8 df in the control to 7 df (instead of from 4 to 3). So, you could basically "hang" the weight off the remaining diagonal, and then use the working off-diagonal rotors to keep roll/yaw/pitch in line. But then the rotors on the diagonal have to generate twice the force. I'd rather not be a pax in this when two rotors fail.

And if one on one side went out, you'd immediately descend.

For drone-style helicopters, I find the Volocopter (https://www.volocopter.com/de/) the most intriguing concept. The designers of the Volocopter took extreme care for redundancy. It can keep flying with up to 6 of the 18 rotors failing. Even the electric system and the controls have multiple redundancies. The first craft already got licensed for flying in Germany.

Much prefer the Volocopter as well. Better redundancy, further down the line (manned flights since 2016, negotiations with regulators progressing), not vapourware, more visually pleasing (though that's subjective, obviously).

In this design, I like the compactness (foldability), counterrotating rotors (for efficiency), the fact that the rotors are not in knee-height (like in this eHang 184 abomination), and the electric/fuel hybrid system.

BTW, I like PEVA as a name for this type of vehicle: Personal electric VTOL aircraft.

EDIT to add: Volocopter and eHang 184 have been around for years, and SureFly "reinvented" the helicopter? Right...

Video "tour" here (still doesn't show it flying): https://www.youtube.com/watch?v=elhiaxMiRuY&t=19s

Also, the inaugural flight at CES was scrapped due to a "light sprinkling" of rain: http://www.bbc.com/news/technology-42616034

It's frustrating, and a bit strange, that there's no (easy to find) video of it in flight.

Couple of people mentioning the Robinson R22 (a 2-seater small helicopter that costs about $280k.) I didn't see any mentions of the Yo-Yo 222 though, which seems very interesting and only costs €135k. The SureFly is substantially slower and has a lower payload compared to both.

It's worth noting, though, that any small aircraft will have very similar payloads (300-400 lbs max.) This will almost certainly not get better in the near future, even with battery improvements (you'll note that all current light aircraft, including this one, are gasoline powered.) Speed is also difficult to increase for VTOL aircraft like this one.

I build custom VTOL (and sometimes horizontal) aircraft, typically electric, usually smaller than this one. If anyone else here builds VTOL aircraft/large drones, send me an email! I'd be curious to talk to other HNers doing the same thing. (And if you're just curious about the subject in general, feel free to send me an email also - it's in my profile.)

> 1 hour of fuel

> 70 mph speed

This means that the maximum legal range with FAA-mandated fuel reserves is 46 miles (assuming no wind). Also despite shots of it on a driveway, it would most likely be impossible to actually take off or land on your driveway due to local ordinances in most cities. Oh and it doesn't appear to be properly equipped for IFR, so clear weather operation only.

Rotorcraft fuel requirements are different from airplanes. Under VFR it's first intended point plus 20 minutes, day or night.

thanks, will edit

Flying fixed-pitch copters is risky. The question is: more risky than driving in traffic? More than taking the bus or swimming or eating fatty foods or a hundred other things we do without blinking?

Still, it'll have to have a measured safety record before I'd want to fly it. Better yet, automate it to go from heliport to heliport in a crowded city, a sort of aero-lyft. So I don't have the chance to screw anything up. Because I'm thinking the human operator is going to be the root of any accident stats. Imagine a swarm of these over your city, with humans in control.

I think it'd be interesting if it were semi-automated. For example: Get in, start it up, hit the "Go" button, and it automatically hovers vertically to minimum cruising height (i.e. above all the houses, trees, power lines) before granting further control to the pilot^Wuser. Then, either GPS-powered destination selection or mobility with computer-stabilized limited degrees of freedom.

The fewer decisions the human in the seat has to make, the safer they are.

Can anyone verify if this thing is actually built and not just some rendering? The shallows in some of their pictures don't seem right so I was wondering if those are pictures of an actual craft or just a Photoshop.

There is a video of it at a trade show on YouTube. The craft definitely exists, whether or not it flies is a different question.

https://www.youtube.com/watch?v=Ll-3jDTibSQ

Yet another really big personal quadrotor-type drone. Its a lot like the eHang 184, from 2016.[1] That flies, but they don't trust it with a live passenger yet.

Here's one with a passenger, but they don't want to get any altitude.[2] There are five or six projects like this. Few have flown with a human on board yet.

[1] https://www.youtube.com/watch?v=qPARvS31Oq0 [2] https://www.youtube.com/watch?v=V3pi4HfQ0Gc

If they wanted to prove the design, why can't they offer package delivery services with the drones and ramp up volume to at least 100 flights a day until it's proven?!

If they've proven it works, they should get the money necessary to test it and deploy it. They need to get to market and see if it sells.

I think the problem is crashing over populated areas, even if it's not occupied? Hard to make deliveries if you can't fly over actual people.

But in any case, let me know when they are doing at least 10 flights per day (no days off for bad weather, they should be testing in multiple locations and climates too).

It would be difficult to get FAA approval to offer cargo delivery services with a large drone due to the risk it would pose to manned light aircraft flying under VFR. They would have to carve out controlled airspace in a specific area and temporarily ban VFR flights there.

Wait:

- Curb Weight: 1100lbs

- Max Takeoff Weight: 1500lbs

So... you, your passenger, and any cargo combined can't weigh more than 400 pounds? That's a pretty serious limit for people hoping to transport multiple adults. And "precision agriculture" or the sorts of practical uses they discuss all go right out the window.

400 lbs capacity for passengers / cargo is in line with an R22, a common 2 seater helicopter (389 lbs for Pilot, Passenger and Baggage). However the SureFly situation is likely worse than that. Typically the empty weight does not include fuel weight, which might be another 100 lbs.

It seems that SureFly has designed an aircraft with less than half the range of an R22, that can't autorotate, and costs roughly the same. The SureFly might be easier to fly though.

https://robinsonheli.com/r22-series/

> However the SureFly situation is likely worse than that. Typically the empty weight does not include fuel weight

Empty weight does not typically include usable fuel, but curb weight, which is what is cited here, generally does (though it's not a figure usually, IME, specified for aircraft).

I'm sure the Max Take Off weight is even lower at altitude and in warm weather. I've noticed most R22 pilots are pretty skinny.

You should look at the usable payload of a Cessna 150 or Piper Cub, and keep in mind that figure includes fuel, if you think that's low. Weight and balance is something you have to pay close attention to in aviation in general, and what your passengers are carrying does matter.

The BMI chart maxes out healthy weights at 192. So unless you have two NBA players or something, it should work well for most but perhaps not all healthy people.

Average weights (no median, sorry) from the CDC (https://www.cdc.gov/nchs/fastats/body-measurements.htm):

>Men: 195.7 pounds

>Women: 168.5 pounds

So this could carry an average man, average woman, and under 36 pounds. At that point, the weight of your clothing or a bottle of wine becomes very important.

Yes, I did say healthy, which a good half of the USA isn't.

but that still implies a 100m person market, just in the USA, and people in other developed countries tend to be closer to the "healthy" range. There are lots of healthy people out there.

In short, I don't think this will be the make-or-break for flying cars...

> a 100m person market

No, not really. Only extremely wealthy people can buy this. It's more like a 10,000 to 100,000 person market in the US I would guess.

Maybe the US version should have one seat :)

What chart are you looking at? BMI is based on height, so someone 6'4" tall has a normal healthy weight range up to 205lbs.

For quite a while, electric VTOL aircraft will be quite limited in what they can carry, I think, because the specific energy of batteries is just too far below that of gasoline.

Its perfectly fine for two adults + a bit of cargo for immediate use.

I thought gasoline turbine generators are sort of here (used in hybrid buses), womder why they stuck with piston generator.

Also, any ideas what battery pack you’d need to do the same 70miles?

My best guess is fuel efficiency at small size scales and is probably the same reason that make them economical in large buses, but not small cars. The usual intuition is explained using the Reynolds number, a dimensionless quantity that can help to predict the possibility of maintaining laminar flow or wether the flow breaks down into turbulence in the generator, drastically reducing efficiency in the compression-combustion-expansion cycle. As a side note, when I did a type rating on the Eurocopter AS350, I learned that the gas turbine could also run on normal automobile gasoline instead of Jet-A 1 for a limited amount of time in emergencies with drastically reduced limits on altitude, torque etc...

It's my understanding that most gas turbine engines can be convinced to run on a wide range of flammable liquids, with some impact to performance and longevity. That the AS350 is actually designed to do so is interesting.

It is cute to show it in a parking lot, but with those unprotected blades it is unlikely you will be able to operate it anywhere but on an airfield, helipad or private land, for safety reasons. And with four sets of contra-rotating blades (small, therefore turning fast) and a gasoline engine, it will be noisy as hell.

Guaranteed vaporware. If these guys had even a fraction of a clue they would have gone with a 6 rotor design.

I'm almost sure this is a champion satirical comment.

I'm skeptical of a company that is doing so many different projects, and none of them seem particularly well developed, far along, or consistent within the framework of some core vision.

That being said, I'm jealous. Where do people actually get money to finance these pet projects?

dumb question, but why would it not be a good idea to enclose the blades so anyone walking up to it won't be hurt? (just a simply loop / bumper arrangement?

on a side note, I hope to be around where a Blade Runner like Spinner is a thing or at least a possibility

What is the benefit of more, smaller rotor blades over fewer, larger ones?

I thought that the area of air that the blades worked on scaled with pi-r-squared, which favours fewer larger rotor blades, as seen on most helicopters?

I can't think of any benefits of this layout other than reducing the size of the landing field you'll need. And I guess less complexity on the part of the rotors, no tail rotor with associated dangers etc.

I can think of some significant downsides though.

1. This is fixed pitch, not collective pitch. That means any change in the attitude of the aircraft requires one or more sets of rotors to change their speed of rotation. This means that you need top notch electronic control systems, gyros etc. to mediate between pilot input and what the aircraft does. These electronic systems are sensitive and fragile and degrade with time. And when they let go, it's spectacular.

2. A loss of any one of the 8 motors is a Jesus Christ, yank the ballistic parachute moment. This is likely a hull-loss event as there will be all sorts of load-bearing parts with the job of absorbing the opening shock of the parachute. These will at minimum require inspection prior to the aircraft being certified airworthy again.

3. related to 2 above, this aircraft has no capacity for autorotation whatsoever. A traditional rotary-wing helicopter with collective pitch can autorotate safely in to a controlled landing in the event of an engine failure. If you lose an engine in this, and your ballistic chute tangles or doesn't deploy properly, you are proper fucked.

It's cool, and quad-copters are fantastic cargo and gp platforms. But I would never fly in one.

Expanding on your point #1: The inertia of large props means they can't change speed quickly, so there will be lag in the control inputs. (In toy quadcopters, electric motor torque is so high vs prop inertia that lag is a non-issue.) Collective pitch controls don't exhibit this lag. Electronic controls can compensate for inertia lag to some extent, but they have to be carefully designed using control theory, and if they fail the copter will likely be uncontrollable.

> A traditional rotary-wing helicopter with collective pitch can autorotate safely in to a controlled landing in the event of an engine failure.

But not in the event of a propeller or pitch-control failure. Also probably single propeller failure in this quad will mean "we lost 1/8 of power, we must land". Also if you lose gasoline engine, you have battery backup for 5min.

You are correct, much better lift, speed, economy from a single large slower moving rotor (or a pair of counter-rotating blades, cost/benefits described in other posts).

The reason all the cheap drones use 4 or more engines is that they can individually be very simple, with the motor directly driving a rotor. With no swashplate to alter blade pitch the mechanism is very simple. Short blades are easy to make for a required strength and stiffness, and the torque of electric motors is sufficient to rapidly change rotor speed to change lift for steering. The control system is simple. However efficiency is terrible, both in terms of lift, and maneuvering.

The energy to change blade speeds constantly to maintain attitude is a significant cost. But having low rotational inertia, frequent changes are required, especially in windy conditions. As blade diameter increases (and hence inertia) the resulting energy costs to change speed increase too, as does the size/power/weight of the motor.

With multiple smaller rotors you control by differential speed of the rotors, which are then fixed pitch, and much simpler mechanically. Smaller (lighter) rotors allow for quicker speed adjustments.

Coaxial counterrotating rotors, as here, have two further advantages:

1. they're much more efficient, as less energy is converted into (useless) air rotation.

2. in forward flight, one side of the rotor "sees" higher relative speed, thus extra lift, while the receding side sees less lift. That's cancelled out by the counterrotating rotor above.

Generally, larger diameters are good for hover performance and better autorotation, though autorotation is not really a factor for this design.

EDIT to add: Note that the total disc size of one large rotor is of course the same as the one of 4 smaller ones with half the radius.

Just reading through the about page... Where is the aircraft/rotorcraft experience in upper management? There are many reasons that helicopters are dominant at the scale of human transport (some of which have been brought up in this comment thread) and multicopters are prevalent at smaller (drone-size) scales...

All of this is to say I'm extremely skeptical.

All that is missing is mention of blockchain.

The fully electric Lilium out of Germany is a far more interesting project. Without a gas engine, the noise and cost problems are greatly mitigated.

I don't know how far away it is from commercialization, but it would appear that the the proof of concept is coming along nicely.

https://lilium.com/

Most of the work of the helicopters I see involve long flight times and/or the ability to carry some sort of not-insignificant payload (camera/sensors/pesticides/people).

This doesn't seem to address either of those situations very well. And with 1 seat to sell, you aren't going to be getting many short charter flights.

The rest of your comment seems right to me, but the title says "personal helicopter"; charter flights are not personal use.

Is there any data on the sound profile of this thing? As the rotors become smaller the disc loading increases, making them much louder and more shrill. If that's effectively mitigated here, this looks really cool; if not, I think it will be hard to negotiate take off and landing rights with most communities.

As well as being higher pitched, contra-rotating designs also produce more noise.

The sound field is non-uniform (mostly axial), and there are claims of being able to reduce it through special phasing of the two rotors, using different numbers of blades on each, etc. But I wouldn't be particularly hopeful.

How am I supposed to "store it inside a standard garage" if it doesn't have wheels to move it in?

It looks like casters could easily be added. Or you could even land it on a dolly.

A lot of light helicopters are transported on dollies or trailers.

Robinson light helicopters have mounting points on the skids where you can temporarily attach small wheels to move them around on the ground.

Why this and not single-rotor collective pitch? There's no good explanation in the marketing material.

Probably to make maintenance simpler? That's the most expensive part of operating a helicopter.

That's the whole point of these drone-like copters: instead of one engine and main rotor with mechanically complicated collective pitch, you have many fixed-pitch variable speed rotors sitting directly on an electric motor. The complexity thus wanders from hardware to control software.

Having written both (albeit only at a hobby scale), I'd argue that the control software for a collective-pitch helicopter is substantially more complex than for a quadcopter, and especially this style of over/under counter-rotating octocopter. To me this almost seems like an effort to simplify the automation and control software at the expense of safety and efficiency.

I do agree that the mechanicals are much simpler. I can see some maintenance and inspection safety gains but the airframe as a whole seems more dangerous. The over/under counterrotating prop design is both inefficient and prone to cascading failures mandating deployment of the airframe parachute.

Interesting. Now, clearly, humans can (with considerable training) fly helicopters with controls that influence the mechanics fairly directly (cyclic, collective, rudder, thrust).

Can humans fly quadcopters with controls that influence the mechanics fairly directly, or do they always require mediation via complicated control software?

Come to think of it, presumably you can (as you have 4df in the controls, and you could have rotors next to each other rotate in opposite direction, and then control the sum of all speeds (=height), sum of left vs sum of right (=lateral movement), sum of front vs sum of back (=forward movement), and sum of diagonal 1 vs sum of diagonal 2 (=rotation) independently, thus translating human inputs into your 4df. Nice!)

> simplify the automation and control software at the expense of safety and efficiency.

At any rate, I continue to think that the much simpler mechanics and motors are the main drivers. Let's see how the accident rates turn out, but I'm optimistic.

> The over/under counterrotating prop design is both inefficient

How is it inefficient? I understand that over/under counterrotating props are more efficient, inducing less air rotation.

Neat!

Although I think it only goes about half the speed, half the flight ceiling and a third the range of an average helicopter. Maybe if these guys get some market traction a ton of other entrants will come and the dream of personal flight will finally “take off”.

I wonder what maintenance requirements will be like.

> target price: $200,000

That's 148,019.4 GBP. The average wage here corrected for a proper living standard is about 22,000 GBP give or take.

If everybody that could afford this took that money and gave it to homeless foundations, what a world we could live in...

price could go down if more affluent people buy, eventually it can become something the average people could "afford"...there are of course other arguments against everyone owning their own flying machine.

Is that even the ethical approach here, though. If you can afford a flying machine, you can afford to keep a roof over a family for 3 years (Assuming two earners earning 22,000 GBP / year (Which is far more than my parents ever earned in their lives)). Or you could pay 6 people's expenses off for a year.

If you have that much disposable income, and you spend all of it on something that benefits only yourself, what does that say about you as a person?

2 props per arm, contra rotating. Eight motors...Gasoline Piston Engine drives dual generators...Dual Lithium Battery Pack...Full computer and electrical system redundancy...Ballistic Parachute...

for simplicity

> Flight ceiling: 4000ft

I’m wondering if that’s the absolute service ceiling or it’s legal operational ceiling due to its classification.

I suppose they won’t be selling them in Denver if it’s the former.

I don't recall there being anything special about 4000' from a regulatory perspective so I suspect that's the service ceiling.

I'm always extremely skeptical of these things. The engineering is difficult, but the person at the controls is an even larger problem.

“One hour of flight time available per tank of gasoline”

So like what, $70 round trip commute? Hmm.

I have to say, I've never worried about being hit by a helicopter while riding my bicycle.

Is this the next Uber vehicle?

Or Amazon delivery "drone"?

So what sort of fuel mileage does it get?

Well that's going to kill someone.

So cool, it looks like a huge drone.

As both a rotorcraft and fixed wing pilot, I really don't want this to succeed. Most people have no business on the road, let alone in the sky.

That's without even getting into the safety issues with this thing that are being conveniently glossed over in the marketing material, which would lead anyone who didn't know better to think a BRS is some kind of foolproof sure thing.

electric transmission vs mechanical and 8 tiny inefficient props?

1 hour flight with 30kg of fuel?

I can make something more efficient in a garage...

Well, Colin Furze can make it in his garage.

https://www.youtube.com/watch?v=soxxPyaAT1k

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