VTOL On Demand Mobility

Looking at these things from the urban air taxi viewpoint, and particularly the to/from airport commute they're touted for, a lot of the teams seem to have paid remarkably little attention to physical passenger ingress/egress. Okay a lot of them are proof of concept vehicles rather than true prototypes, but if your concept puts multiple waist level rotors and a huge outrigger between passenger and door (looking at you, Boeing), then that's a problem. Doubly so when the passenger is towing a suitcase the size of a small house. Air travellers have luggage, but to look at many of these vehicles you wouldn't think so.

And you can multiply the problem again for passengers who are wheelchair users, or otherwise mobility impaired. Embraer's is the only concept I've seen to even mention disabled accessibility, and I'm not completely convinced even they understand the practicalities as their landing skid will complicate boarding, and they presume a folding chair, where the majority of long-term independent wheelchair users use non-folding rigid frame chairs. Nor are these theoretical issues as both ground taxi and aircraft regs (for example the Air Carrier Access Act) commonly require carriage of wheelchair users. And what applies to wheelchairs similarly applies to baby buggies, which, incomprehensibly, are often larger than adult chairs.
 
VTOLicious said:
EASA takes the first shot at eVTOL regulations. Did they miss the mark? (by Mike Hirschberg, executive director of the Vertical Flight Society)
https://evtol.com/opinions/easa-first-shot-evtol-regulations/
Click to expand...

The TLDR might be "Wah, they want us to be as safe as airliners!"

Well, you're talking about an industry potentially carrying as many people as airlines, or more, when fully developed, and doing so in many more air vehicles, while spending more time in close proximity to urban areas, and with a lower chance to glide or autorate clear of trouble due to a likely lower operating altitude. So from the other perspective they're lucky they only want them to be as safe as airliners.

And thinking about this, it's just occurred to me to wonder whether anyone has modelled the likely shortfall in licensed aircraft mechanics if we see the sort of growth mooted for eVTOL/urban air vehicles.
 
I will repeat the adage: People DRIVE badly enough, do you REALLY want to give them a third dimension in which to do so?

The reasons we don't have flying cars is neither technical or economics but the general fear of what that would really mean :)

Randy
 
I will repeat the adage: People DRIVE badly enough, do you REALLY want to give them a third dimension in which to do so?
Click to expand...

Mathematically, yes. A (second and a) third and a 4th (time).
That to drastically decrease the probability of collision. Add the lowered rate of ownership (cost and preferences) and you dwarf the numbers.
 
When it comes to the major claim about noise they’re using a chalk and cheese comparison.

Noise is a simple function of the energy added to air. A five ton six seat helicopter sized for several hours endurance is naturally going to require an order of magnitude more energy to fly than an unloaded, at best single seat, model which may only have a practically airborne endurance of a few minutes. Having done the sums myself I find most of the eVTOL time of flight claims dubious;- commonly these only assume two dimensional flight;- going up and down kills range and endurance figures so they ignore it. So again Helo’s can fly high, noise a long distance away, whereas eVTOL will be a few metres above your roof.

Let’s hear the noise when they have a valid basis for comparison.
 
Last edited:
Zootycoon said:
When it comes to the major claim about noise they’re using a chalk and cheese comparison.

Noise is a simple function of the energy added to air. A five ton six seat helicopter sized for several hours endurance is naturally going to require an order of magnitude more energy to fly than an unloaded model which may only have a practically airborne endurance of a few minutes...
Let’s hear the noise when they have a valid basis for comparison.
Click to expand...

I was waiting for that comment... And I fully agree. The noise comparison in that video is absolutely ridiculous.
It will be interesting to see how noisy a large and fully loaded vehicle like Cityairbus will be. And downwash is most likely an issue as well ;)
 
VTOLicious said:
Hey guys, turn up the volume!
Note: Volocopter is considered to have a rather low discloading.
https://twitter.com/x/status/1181560099711664128
Click to expand...
I'm just wondering, with 10 or 12 props, is there any form, of synchronisation, or indeed de-synchronisation, possible? Just like the supersonic teams are trying to spread the shockwave.

On the driving v flying, I understood these would all be automatic, we surely are not talking about my 93 YO neighbour getting one of these and flying themselves are we?
 
All these vehicles will be autonomous, although they will initially have a safety pilot. Some of these configurations are unflyable anyway without FBW, there will always be a computer in the loop.
 
Well our Aerospace institute here in Indonesia also have its take

kabar24.bisnis.com

Lapan Luncurkan Dadali, Drone Pengangkut Manusia

Lapan meluncurkan Dadali, drone atau pesawat tanpa awak untuk pengangkut manusia (urban transporter) yang diciptakan oleh PT Aeroterrascan dan PT Chroma International.
kabar24.bisnis.com kabar24.bisnis.com

--
One claim i heard is that this is safer than Helicopter.. Which made me wonder how such can be achieved ? It does have multiple rotor but how many lost rotor that can be tolerated ? Plus is there any ability to auto-rotate so in case of total power loss.. the rotor can safely glide and land.
 

Unfortunately no full transition. And quite surprising that an aircraft of that size doesn't have any registration markings!?
 
Even though it’s obviously not a full transition that hasn’t stopped Lilium’s head of communication claiming it is, ref interview with eVTOL.com.

The company is in a fund raising round, half a billion, which if successful will value the company at 2-3 billion. The projects main backer (I can see why he didn’t stick at bobsleigh) is currently in for maybe a 100mil is set to make a serious return.

I mean just look at the landing gear and ask when five people are on board, just deep will it be driven into the ground? ..... would you trust the health of your back to this in the event of a bit of an arrival in turbulence?

Also have you noticed it doesn’t produce noise, only stirring music?

Deception in plain sight
 
Last edited:
It's pretty quiet around flight test progress of CityAirbus
 

Attachments

  • 20191027_075706.jpg
    20191027_075706.jpg
    481.8 KB · Views: 93
VTOLicious said:
It's pretty quiet around flight test progress of CityAirbus
Click to expand...

Audi/Italdesign have suspended their very complex Pop Up Next project and are reviewing their collaboration with Airbus apparently.

www.carscoops.com

Audi Grounds Their Flying Car Project | Carscoops

The company has suspended work on the project and is reviewing their partnership with Airbus
www.carscoops.com www.carscoops.com

This is a separate design but broadly related to the CityAirbus. With CityAirbus and Vahana, I presume that they're continuing, since there's actual flying hardware being tested.
 
Hi,

nbaa.org

Uber Elevate Summit Highlighted Innovation in eVTOL and UAM Markets

Uber Elevate Summit 2019 highlighted innovations in the electrically powered vertical takeoff and landing (eVTOL) and urban air mobility (UAM) markets. NBAA sponsored the event in its ongoing efforts to ensure safe integration of emerging technology and optimized utilization of new technology...
nbaa.org nbaa.org
 

Attachments

  • 2019-uber-elevate-summit-1097x731.jpg
    2019-uber-elevate-summit-1097x731.jpg
    66 KB · Views: 79
hesham said:
Hi,

nbaa.org

Uber Elevate Summit Highlighted Innovation in eVTOL and UAM Markets

Uber Elevate Summit 2019 highlighted innovations in the electrically powered vertical takeoff and landing (eVTOL) and urban air mobility (UAM) markets. NBAA sponsored the event in its ongoing efforts to ensure safe integration of emerging technology and optimized utilization of new technology...
nbaa.org nbaa.org
Click to expand...
The eVTOL model depicted is one of Uber's Common Reference Models (CRM-03). Safran designed the cabin for that particular model...
 
Looking at that from my perspective (on wheels) it's an absolute disaster for accessibility. The seats are a good .5m inboard of the fuselage mould line, there appears to be a running-board style step outboard of that in some of the illustrations and the initial vertical mockups shots, but not the later ones side-on to the mockup. Floor level appears to be above knee. I don't know any non-ambulant wheelie who can do a .75m vertical, .75m lateral side transfer, most transfer boards are far shorter. The doors appear to interfere with where you'd want to put the chair for accessing the seats for all three rows, potentially to the point access is just non-feasible. I can stand if I need to and boarding still looks to be incredibly awkward. Luggage space appears very tight for a rigid frame manual chair.

But they've made certain there's a holder for your coffee and room for your guitar, so that's all right then.

ETA: Found a better still. There's room to position your chair to access the rear seat, but the retractable step is a definite problem and luggage space is utterly inadequate for a rigid chair (even before they fill the space with 'uber eats'). And it definitely looks like they're assuming a piloted vehicle.
Safran-Uber concept air taxi.jpg
 
Last edited:
TomS said:
VTOLicious said:

Boeing’s PAV eVTOL Prototype Crashes | Aviation Week Network

Boeing’s full-scale Passenger Air Vehicle eVTOL prototype has crashed during unmanned flight testing at subsidiary Aurora Flight Sciences in Manassas, Virginia.
m.aviationweek.com m.aviationweek.com

Paywall... No further info
Click to expand...

Confirmed various other places but no details other than that it crashed in a controlled area and caused no injuries or damage to anything except the vehicle itself.

www.ainonline.com

Boeing's Autonomous Prototype Crashes | AIN

Company officials mum on details of the crash, which occurred June 4.
www.ainonline.com www.ainonline.com
Click to expand...

Airframe vibration led the control system on Aurora Flight Sciences’ Pegasus passenger air vehicle (PAV) to shut down the lift motors during landing, causing the electric vertical-takeoff-and-landing (eVTOL) prototype to crash, the preliminary report into the June 4 accident says. The unmanned PAV was on a development test flight when the crash occurred at Manassas Regional Airport in Virginia, says the U.S. National Transportation Safety Board (NTSB) report.

Subscription required: http://m.aviationweek.com/awinbizav/aurora-evtol-crash-caused-vibration-affecting-flight-controls
 
Corresponding NTSB Report:

The aircraft was positioned on runway 34L for a vertical takeoff and landing, along with low speed maneuvering test. The aircraft took off normally and the pilot, who controlled the aircraft from a ground station in a building on the east side of the airport, entered pre-planned flight test stability check maneuvers, including brief lateral maneuvers followed by forward translations along the runway centerline in accordance with the test plan. The flight test engineers noted some brief data dropouts and abnormal motor speeds, and the team decided to terminate the flight. The pilot entered the autoland command, and the aircraft initially responded. After a small descent, the aircraft motors went to idle and the aircraft descended vertically at a high rate and impacted the runway, breaking the aft booms, the horizontal stabilizer, and other significant structure. The #3 motor exhibited a brief flash of fire or sparking on impact.
...
A review of the recorded data was provided by the operator/manufacturer revealed that airframe vibration occurred in a resonant mode and was transmitted through the structure into the flight controller. The accelerations resulting from the vibrations briefly exceeded the jerk logic threshold and the aircraft entered the ground mode, subsequently commanding the motors to shutdown.

https://www.ntsb.gov/_layouts/ntsb.aviation/brief.aspx?ev_id=20190604X91518
 
So they do a sort of "weight on wheels" detection via accelerometers rather than a separate sensor, and the resonant vibration convinced the system that it had already touched down (the "jerk" metric presumably supposed to indicate reaching the ground in a controlled fashion). That's amazingly bad luck that the resonant mode happened to hit the same parameters.
 
The fact that it entered a resonant vibration mode in such basic flight condition point to an uncompleted design study. This thing was not ready to fly.
 
TomS said:
So they do a sort of "weight on wheels" detection via accelerometers rather than a separate sensor, and the resonant vibration convinced the system that it had already touched down (the "jerk" metric presumably supposed to indicate reaching the ground in a controlled fashion). That's amazingly bad luck that the resonant mode happened to hit the same parameters.
Click to expand...

I hope their "weight on whatever it has" is more complex than just a single accelerometer threshold! Lots of things that can generate a quick g-input, micro-burst pops to mind as one you might encounter in proximity to the ground.

Though given it's an unmanned test vehicle I suppose safety standards are lower than for a commercial passenger vehicle. (Career safety when you have to explain the loss to your boss may be more of an issue).

On top of that, there are two other symptoms reported - data drop-outs and motor speed fluctuations. I can see the vibrations potentially causing data-dropouts, but if they're physically causing the motor speeds to vary, presumably by causing rotating parts to intermittently bind, then that was some pretty severe vibration.
 
While the future of autonomous, urban air taxis has drawn new players and bold plans into the aviation space, Sikorsky has been quietly developing its own solution, putting itself at the head of the helicopter autonomy space, Wired online reported.

In the next year or so, it will include Matrix features in the Black Hawks it builds for the US Army. Applications like oil rig transport and search-and-rescue missions will follow. And yes, this tech could someday enable those flying cars we keep hearing about.

The company, which Lockheed Martin acquired in 2015, recently announced it’s formally entering the urban mobility race, using the Matrix system, electric propulsion tech, and its data systems. Already, Sikorsky says that the Matrix tech is essentially ready to start piloting flying cars — even if those flying cars don’t exactly exist just yet.
Click to expand...


www.asiatimes.com

Sikorsky presents a touch-and-go copter - Asia Times

As helicopter flights go, this one was especially boring. We took off, hovered for a bit, and maneuvered around the airport. We flew to a spot about 10
www.asiatimes.com www.asiatimes.com
 
Just been thinking about urban air mobility. Assume we reach the sort of volume the likes of Uber are talking about. Lots of air vehicles flying short hops, which means a significant growth in the percentage of flight spent at low altitude vs today, and potentially flying into less well regulated sites, which, in the likes of Uber's dream, could be any street corner.

The wire and other low-altitude obstacle collision hazard goes through the roof. Yet none of these concept unpiloted vehicles that I've seen to date seem to have see and avoid technology mounted.
 
The city will adapt. We will see a gold rush for vertical growth and horizontal link b/w structure. I have a 3d concept model somewhere but think metro city but upside down ;)
 
Last edited:
Bell Nexus design changes to more conventional 4 rotor arrangement. Main wing for rear rotors looks like it provides more lift as well. Bell's website says the design intention is all electric but can be configured as hybrid-electric during initial operations.

I'm guessing cost/noise tradeoffs have moved Bell away from the 6 rotor configuration. They don't go into any details explaining the design change. This design clearly can't take an asymmetric rotor loss like the earlier version so it will be interesting to hear what they have to say.

https://twitter.com/x/status/1214158558436249600


Nexus 4EX.jpg
 
Dallas Business Journal has a bit more:
Bell made the changes to the 4EX after hearing from potential customers that the vehicle would most likely be used in an interurban environment. The reduction in ducts reduces drag which increases efficiency, Bell officials said, while the six-ducted model offers greater range.
Click to expand...
So this is the interurban version of the same concept, the 6-rotor version is possibly still in play if customers are interested.
 
I have a hard time thinking this thin wing can provide any lift in an urban environment. Flying 150 b/w buildings... No way.

Edit:
See below with 290 as target cruise speed and way too much range for max altitude. Nobody is gonna cruise half an hour in dark (cloud) and turbulences.
100km range makes that you have only one way to bypass the weather: alt.
Ppl have to think that those aircraft are gonna be light, hence thrown in every direction in weather. As I have written before, if those guys don't want to be known for inventing the Vomit comet, they'd better come with a refined strategie...
 
Last edited:

Similar threads

Back
Top Bottom