VTOL On Demand Mobility

Found out more about the Tri-Wing from the German flying model forum I got the video from:

"It is the result of intense development of own software for the flight controller and a lot of work around the homemade EDF units including very smart directional thrust control units. There are a few other tricks like ultralight fuselage covered with thermo-vacuum formed 1.5mm Depron etc.

Maker and pilot is Dietmar Metz.

It is a model of the collaboration of Porsche with Lucasfilm named Tri-Wing S-91x Pegasus Starfighter."

What I find interesting about it is how controllable it is and how little turbulence it stirs up when it is flown in the tent. A helicopter or V-22 model that size would stir up a lot of air and be blowing lightweight airplanes off tables as well as the rotor blades being too dangerous to be allowed near people. This model uses 3 tiny electric ducted fans and thrust vectoring flaps. I don't know how well this model would do man sized, but you already know how much trouble a V-22 causes when it crashes a picnic.
 
We finally get to hear what the Lilium evtol prototype sounds like on approach. Pretty quiet.

So what was the ballasted weight? Was the microphone muffled or suited to far field recording? Has the sound track been post processed?

Remember this is a company with a reputation for years of corporate deception;-predicted in service dates missed by large margins, range claims outside the laws of physics, claims of wing born transition demonstrations which were obviously hover taxing (it was just a simple quadcopter), claims that within two and bit. years it’s certification/safety will match a civil aviation standards, I.e a loss model of one in a ten power nine, and claims that that their technology will quickly yield a viable seven a seater.

A sudden burst of honesty?, quite out of character. It’s astonishing that this far into the program there hasn’t been a genuine wing flight transition which suggests there’s obviously deep concerns if it’s fundamentally capable of doing such. And again if this ends in a drama what will that do to their SPAC valuation? …. Best not try eh.
 
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The USAF awarded Jetoptera, Inc. a Direct to Phase II Small Business Innovation Research (SBIR) contract. Jetoptera will design, build out and test an Upper Surface Blown Wing (USB) equipped, powered high-lift test article integrating Jetoptera’s Fluidic Propulsive System (FPS™), to characterize and further demonstrate the potential of FPSTM to create a signature managed propulsion for VTOL aircraft. The experimental data will be used to deliver a conceptual design of a High Speed Vertical Take Off and Landing (HSVTOL) aircraft.

 
The USAF awarded Jetoptera, Inc. a Direct to Phase II Small Business Innovation Research (SBIR) contract. Jetoptera will design, build out and test an Upper Surface Blown Wing (USB) equipped, powered high-lift test article integrating Jetoptera’s Fluidic Propulsive System (FPS™), to characterize and further demonstrate the potential of FPSTM to create a signature managed propulsion for VTOL aircraft. The experimental data will be used to deliver a conceptual design of a High Speed Vertical Take Off and Landing (HSVTOL) aircraft.

Can someone smarter than myself please explain to me how USB fits in a VTOL scheme? USB has historically been used for wing lift augmentation and STOL. It also relies in having a very specific nozzle shape, not sure how Jetoptera's 'open loop' nozzle fits into this...
 
The wing USB just gives direction to the airflow thanks to the Coanda effect. The Ejector gives the mass flow.
It's a result of air viscosity with each layer acting on the other (gases can't create a vacuum).
 
The wing USB just gives direction to the airflow thanks to the Coanda effect. The Ejector gives the mass flow.
It's a result of air viscosity with each layer acting on the other (gases can't create a vacuum).
Yes, a.k.a. "entrainment".
I don't know that the Jetoptera setup can recreate the same conditions that are presumably necessary for an effective USB flap. Compare it to a standard USB arrangement where you have a very uniform velocity profile coming from the nozzle of a gas turbine.

But assuming that this actually works, and who knows, it could be, it still doesn't explain how you achieve VTOL with a USB flap. Simply deflecting the flap ninety degrees at static conditions will not give you a vertical thrust vector. There are turning efficiency losses. Maybe if they partially tilt the wing as well? You actually need to tilt the thrust vector past the vertical in case you are hovering in a tailwind.
 
Not necessarily :

Restoration-Vought-V-173-631.jpg
 

TLDR: confirmation of an order announced in April of 150 Volocopters for its Volocopter Chengdu joint venture with Aerofugia.

Is it just me, or are a lot of the orders coming through for eVTOLs actually going to joint ventures with the manufacturers? Which suggests independent operators are still wary of the sector.
 

TLDR: Brazilian airline Gol to acquire 250 Vertical Aerspace VA-X4s from Irish lessor Avolon, which has 500 on order, though the details sound like all the money is coming from Gol's majority shareholder Grupo Comporte which is simply going through Gol to save setting up a new operator.

I was amused by Avolon's claim this now means they've contracts for over half the VA-X4s they have on order. As 250 is half 500 on its own they just need a single extra lessee for a single extra aircraft for that to be true.

Also amusing is the expectation it'll be certified for operation by 2024 (mid-2025 for Gol) considering they only signed up Rolls-Royce to produce the (electric) powertrain in March this year.
 
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TLDR: turbine-powered quadcopter, 607kg, 7.4m by 7.4m, folds to fit an ISO container, first flight end 2022, 121kts, 362kg (800lbs) to 50nm or 136kg to 326nm either podded or underslung, 523nm self-deployment range with external fuel.
 
I am not sure that you can integrate in many airports with only 60s of vertical lift. I hope that they have provisioned a normal landing mode.

Helicopters, for example, often have to follow taxi procedures while hovering close to the ground.
That's a good point. 60s is optimistic if you're travelling into any sort of hub, with other traffic with its own demands, and all that hover time is eating into your battery capacity. At the end of a flight that could be a problem.

I suspect they could integrate with a conventional airport by approaches and departures orthogonal to one side (only) of the operating runway. Keep them physically offset from anything landing conventionally and give them their own landing pad at the end of the flightline. I'm not saying ATC would welcome them, but keep them in a separate traffic flow and ensure the only point they cross with conventional traffic is significantly height separated and you at least minimise their impact.

Where I'm really not sure the whole eVTOL concept works at airports is passenger flow. They're marketed (to investors at least) as a faster, more convenient version of the taxi to/from the airport. That means your end point has to be close to arrivals/departures, no dropping people half a county away and expecting them to lug everything onto a shuttle-bus. They're competing with walking out of arrivals and diving into a taxi that drops you at your front door, and while they may be significantly faster than a taxi in level flight, they're going to be significantly slower in pick-ups because they can't be co-located with the door to arrivals as easily as a taxi rank. And at the other end they aren't going to be dropping you at your front door, they're at best going to be landing at a pad somewhere in town, forcing you to take a conventional taxi from there. And it only gets worse if the eVTOL departure from the airport is on the flightline, meaning you have to go through security again. I don't think the faster-airport-taxi model works.
 
Noodling some numbers, and specifically operation into/out of an intercity hub rather than an airport to take ATC issues out of it.

Lillium speed =175mph, range = 155miles. Figures from the Lillium web site.

Let's say the hubs are a 15 minute taxi ride from your start and finish locations, and that it takes 5 minutes to swap taxi to Lillium and vice versa
Total journey time = distance/175*60+40 minutes.

Now instead a Taxi over the same distance, assuming an average speed of 50mph, but door to door and no transfers
Total journey time = distance/50*60 minutes

On those assumptions it'll be quicker to take a taxi than a Lillium out to about 50 miles. So that's a fairly distinct 50-155mile range band where Lillium has an advantage. Extending their range looks like a really good bet for extending their operational feasibility. (But then gets fewer trips/day, so you might want to increase speed and range in parallel).

Fast rail, excluding TGV-like, can't compete within Lillium's range, as Lillium is faster and you need to assume similar time to/from station vs time to/from Lillium pads. But as soon as distance is over 155mph fast rail is the only game in town.
 
CATL is marketing a Sodium battery, one can probably look at the spec sheet for a rough idea on how this chemistry would work out.:
Seem usable but inferior, probably make sense in fixed storage and less mass critical applications like trains or ferries and some low end cars.

If we are talking about metal air batteries overall though, it is still far from mature with unsolved cycle life/safety/etc problems and would likely come only after both solid state and silicon anode technology which is decade(s) down the line.
CATL's Sodium Ion battery is more designed for energy storage; i.e, they claim they can get costs down to the 20-40 USD range per kWh, which, with an estimated 1000 (maybe 2000?) cycle life, gets you to 1.25 cent per kWh storage (assuming 20% charge/discharge inefficiency) as a minimum, with 5 cents being the maximum.

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IMO most people looking at VTOL on-demand mobility are doing it wrong. Take-off and landing are big problems for this kind of stuff; you need heliports. The better way to do it would be to envision the lifting units as always airborne, but have them carry a passenger compartment which can be landed and recovered trivially. The passenger compartment then can be landed on a sidewalk, or even not landed at all with a ramp off-loading the passenger. This minimizes the infrastructure requirements for pick-up and landing.

If you base this around passenger compartments which are lifted and dropped by VTOLs, you can switch to a multi-drone arrangement, and honestly, people aren't thinking about how bad the sky traffic can get. Car crashes are very survivable, but if you have a ton of VTOL passenger craft in the air, they'll start running into each other and people will die. They need to be controlled by a central dispatcher or a node-server architecture. A passenger compartment, beyond being easily-landed, can be reinforced with airbags and parachutes to enable safe descent if lift is lost. And since it's being towed around by the VTOLs, as opposed to being part of the VTOLs themselves, VTOL destruction isn't going to lead to dead humans as long as the compartment survives.

Moreover, if the approach is based around passenger compartments instead of aircraft that have to land, you gain further benefits in that you can transition through a cargo transport stage where it's pallets being moved as opposed to passengers. Once the reliability is sufficient, you can just shift from cargo pallets to passenger pallets. Moving to passenger compartments, likewise, present the possibility of doing things with STOVL instead of pure VTOL, which should at least reduce the engineering requirements somewhat.
 
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TLDR: turbine-powered quadcopter, 607kg, 7.4m by 7.4m, folds to fit an ISO container, first flight end 2022, 121kts, 362kg (800lbs) to 50nm or 136kg to 326nm either podded or underslung, 523nm self-deployment range with external fuel.
It seems to feature a mechanical powertrain and collective pitch control on each rotor... Isn't that exactly what you wanna get rid of to increase reliability / safety?
 

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I would suspect that Kaman is going for what is the least expensive route to meet a USMC requirement. That may/may not include a mechanical powertrain and collective pitch control .
 
Be it cyclic or collective, the headache is the electro mechanical servo actuators.
AIUI, once you get beyond a certain rotor size, there is too much rotational inertia to allow precise lift control purely by means of rotor speed. Thus you need collective pitch control.
However, why not use a proven helo platform and convert it into a cargo UAS? Actually it already exists!...
https://www.boeing.com/defense/unmanned-little-bird-h-6u/
From #666 above :-"folds to fit an ISO container". By the time you've re-engineered the Little Bird UAV to fold., you may as well have gone for the clean sheet design . . .

cheers,
Robin.
 

TLDR: "Bristow intends to take up to 100 examples of Eve’s eVTOL aircraft – deliveries are to start in 2026 – alongside pre-orders for 25 of Vertical’s VA-X4 aircraft, plus 25 options."

The article has a picture of a Bristow-branded example of the Eve eVTOL on approach to an oilrig. I really do wonder if any of the current crop have the space and emergency exit potential for a crew of hulking rig workers in survival suits.

OTOH the deal with Vertical strikes me as sensible because it says both sides will set up a working group to collaborate on: "regulatory and airspace; demand, fleet size, spare parts and infrastructure; potential customers; and public acceptance and environmental requirements"
 
CATL's Sodium Ion battery is more designed for energy storage; i.e, they claim they can get costs down to the 20-40 USD range per kWh, which, with an estimated 1000 (maybe 2000?) cycle life, gets you to 1.25 cent per kWh storage (assuming 20% charge/discharge inefficiency) as a minimum, with 5 cents being the maximum.
I wanted to pick up on the cycles issue even if this isn't specifically discussing a battery aimed at the eVTOL market. If your battery life is 1000 cycles, and you're recharging three times a day in the eVTOL role, which is certainly a viable estimate, possibly even an underestimate, then you're replacing your battery pack once a year. And the industry would need not just the battery suppliers to handle that, but the battery recyclers to deal with all those piles of no-longer flightworthy batteries.

IOW, it's not just energy density that puts special design demands on eVTOL batteries, it's cycle life as well. And ease of recycling on top.
 

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