Flying cars ... finally here!

Miscellaneous and Personal Stuff I Must Share
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Flying limousines and taxis will be here long before we have flying Camry’s for everyone.

When considering costs, don’t forget that roads cost something too. Consider a “future city of tomorrow” (I know, let’s call it “EPCOT”; so poetic) that is designed with no roads; everything flies everywhere. One heck of a lot of infrastructure does not need to be built and maintained. That is a hefty hunk of cost avoidance.

To be sure, existing cities and road networks will need to be maintained until/unless flying everything has been commonplace for decades.

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https://upload.wikimedia.org/wikipedia/commons/8/87/Volocopter_at_IAA_2017_1.jpg)](https://upload.wikimedia.org/wikipedia/commons/8/87/Volocopter_at_IAA_2017_1.jpg

Q:

when I see those type of drones, the (limited knowledge) physics in me asks - why aren’t there any ducts below the rotors to channel all moving air downwards (to maximize lift) … instead of spilling dirty air all over the place=

I am sure there are reasons (cant be that I am the only genius amongst those people) … why no down ducts/chutes???

my WAG … ducts need to be too long to achieve any effect - but i am def. out of my depth here

any takers?

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Ducts improve prop efficiency … some; that’s good. They also weigh something; that’s bad. They also require the structure supporting them and the prop they surround to be stiffer and therefore heavier than if they were absent; that’s bad.

For vehicles that tilt their props/rotors to align with the direction of flight they make some additional drag; that’s bad. For those machines that don’t tilt the props/rotors, or tilt them incompletely, and therefore lean the whole machine forward to make up the difference, in forward flight the ducts are big flat speedbrakes set partly or wholly sideways to the relative airflow; that’s extremely bad.

The folks who design these things know how to work out the tradeoffs. The math is well-understood. I conclude the balance works out that ducts are usually more loss than they are worth in gain.

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Responding to an older post, but if this counts as a “flying car” it had two deaths:

https://aviation-safety.net/wikibase/wiki.php?id=2695

In 1973. This is an old quest with many failures.

126

Wow. Anyone idiotic to go up in that thing should have made a will beforehand.

Even though the Pinto was a light car, the total aircraft without passengers or fuel was already slightly over the certified gross weight of a Skymaster. However, in addition to poor aircraft design and loose parts, the National Transportation Safety Board reported that bad welds were partly responsible for the crash, with the right wing strut attachment failing at a body panel of the Pinto.

The Mizar is exactly why people rail at flying cars.

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I wouldn’t get into a Pinto without wings, let alone with them.

From the Wikipedia article:

On a test flight from Camarillo Airport in California on August 26, 1973, according to test pilot Charles “Red” Janisse, the right wing strut base mounting attachment failed soon after takeoff. Because turning the aircraft would put too much stress on the unsupported wing, Janisse put the aircraft down in a bean field. After the roadway was closed to traffic, Janisse drove the otherwise undamaged aircraft back to the airport.

On September 11, 1973, during a test flight at Camarillo, the right wing strut again detached from the Pinto. With Janisse not available for this test flight, Mizar creator Smolinski was at the controls. Although some reports say the Pinto separated from the airframe, air traffic controller Reed Weske, who was watching through binoculars, said the aircraft disintegrated after taking off and making a right turn.[6] According to Janisse, the wing folded because the pilot tried to turn the aircraft when the wing strut support failed. Smolinski and the Vice President of AVE, Harold Blake, were killed in the resulting crash.[6][7]

Hey, that was exactly 50 years ago today. I guess we can say the Mizar is the nine-eleven of flying cars.

Props to that test pilot, anyway.

128

And, ummm… that’s only half a Skymaster. No front engine. And they bolted/welded a freaking Pinto under it. I’m stunned it got off the ground.

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The trick isn’t getting off the ground. Apply enough power anything can get airborne. The trick is landing safely. Which that “PintoMaster” apparently was incapable of doing.

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Ha. I’ve often said that about airplanes. It’s important to keep the wings on for a safe landing.

And other stuff - https://www.youtube.com/watch?v=CHuQy0mqW5I

Huh. That’s an anvil launching video. Can’t get video link to work.

131

i think one of those aspects that get really underappreciated is how much the aerodynamics of a car suck as compared to a real plane …

that alone will make it practically impossible and outright dangerous…

but that chapter is closed, anyway … eVTOL does make a lot of sense compared to hitting a runway with a car to get airborne…

132

OMG. The future has arrived. You want flying cars, you’ll get flying cars.

At the 0:47 mark in the video you see two streams of flying cars flying dangerously close to one another soaring above the very ordinary cars on a bridge. These cars will presumably be used to commute in the 10 Freedom Cities that Trump will build on federal land.

Those of you in the massive flying car voting demographic need to take notice. Flying cars, baby!

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Aha. I bet this is what Trump was referring to.

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Guangzhou-based Ehang on Friday said it received an airworthiness “type certificate” from the Civil Aviation Administration of China for its fully autonomous drone, the EH216-S AAV, that carries two human passengers. U.S.-listed Ehang claims it’s the first in the world to get such a certificate. “Next year we should start to expand overseas,” Ehang CEO Huazhi Hu said in an interview, via a CNBC translation of his Mandarin-language remarks.

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Joby:

Volocopter:

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Will they be allowed to fly down inside the NYC canyons?

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Looks like it needs four parking spaces to land. Where ya gonna find that?

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Four parking spaces? Hmm…

Ed’s Air Taxi: from the far corner of a suburban WalMart parking lot to the far corner of a nearby suburban WalMart parking lot!

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So who has put down a pre-order? [unfortunately I don’t have a spare $300,000 laying around.]

141

Seeing 'SpaceX-Backed" in the headline made my scam sensors go up. It common for fanciful tech companies to try to gain legitimacy by associating themselves with a successful one. So I searched for information on SpaceX backing them. All I could find was that Tim Draper, an early investor in Tesla and SpaceX, has invested some money in them. Yet almost every story describes them
as ‘SpaceX-backed’. They read more like press releases than actual journalism, which is what I expect feom the garbage tech press.

I’ve also seen headlines describing it as “The FAA-approved Alef Flying Car”. The only ‘approval’ it has is for experimental test flights. You don’t need much for that.

Some facts:

The thing only weighs 850 lbs. It has no crash protection to speak of, and can’t be licensed as a road car. It would get the same privileges as a golf cart. It’s also limited to 25 mph on the ground, the same as golf carts and other ‘low speed’ vehicles like Bobcats. The only use case I can think of is… I dunno. Taking off from your driveway? Using it on a farm? I’m not really sure of the utility of a flying ‘car’ that is not road legal.

They claim it has a range in air of 110 miles. This is not very consistent with the maximum weight of the vehicle at 850 lbs. I could not find the battery capacity listed anywhere, probably because it likely won’t add up. EV car batteries range from about 1,000 to 3,000 lbs. Even stripped down for aviation use, a battery that will fly 1,000 lbs 110 miles will likely weigh more than 850 lbs by itself.

It’s advertised as a two seater, but max payload is 200 lbs. I guess two children…

My back of the envelope calculation is that the thing would need more than 40kW to hover, And maybe 60kW for forward flight at cruise speed. So it probably needs a 60kWh battery to achieve its specs, assuming no reserve. Such a battery weighs over 1,000 lbs. Bosch is supposedly working on an ultra lightweight battery that will be about 450 lbs for 50kWh. Thst would leave 400 lbs for the rest of the aircraft, including 8 electric motors, propellers, and the whole structure.

I consider all these flying cars to be vaporware until we see one actually fly the distance they claim with a full payload. Some of them are undoubtedly ‘exit scams’, where some people claim to have solved an in-demand problem, hype the daylights out it and try to build up the value to the point where they can sell it off to someone for enough money to get rich. Then scram before the whole thing falls apart under the weight of its engineering contradictions. I’m not saying Alef is doing that, but enough do that all such companies should be approached with a lot of caution.