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22 August 2020
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Elon Musk and His Flying Car Part 2

I Got A Little Sidetracked Yesterday

I never got to the subject of flying cars as I impliedly promised. That will be remedied below. I also deleted a disclaimer from yesterday's blog which I reinstate here: Anything I say below about an actual, planned Tesla flying car is pure conjecture. I have no knowledge that they are planning one, or, if they are, they will be stealing any of my ideas. (It would be a shame if they don't, though.)

Why Don't We Have Flying Cars?

A: Because they're really hard to make with our current technology.
B: Because we're thinking about them wrong.

Pick any two.

"Really hard" doesn't mean "impossible" and technology is getting better. I'm counting on Tesla. They need to think about them right, and I now conjecture (with total purity) that they are doing just that.

My First (And Hopefully Not Last) Flying Car

It was manufactured by Cessna and called the Model 172. It was very popular as flying cars go. Oh? You didn't know Cessna made flying cars? Cessna itself would be more surprised to find out that they did (and still do). That's because although the 172 was a decent airplane, it was a terrible automobile. Its tiny wheels would get caught in potholes. It would have a tendency to float off the ground at anything beyond school-zone speed. At a traffic light, pedestrians would have to be extremely careful crossing the street in front of it. And it's at least two lanes wide.

No problem! Add big tires and a coupling to turn them from the engine so you don't have to use the propeller on the ground. Don't forget a steering linkage to the front large tire. Make the wings fold so that it's only one lane wide. Add safety features such as a bumper and outside mirrors and you're done. Let's go for a drive!

That went well! Now let's go for a flight. One little problem: By the time you've completed the autoplasty, you've added so much weight that when you unfold the wings and connect the propeller, you can only fly with a negative number of occupants. (No, going on a diet of antimatter won't help.) Converting a plane to a useful car or vice versa is critically dependent on careful engineering and lightweight (expensive) materials. It can be done, sort of, but it isn't easy. Despite my flight of fancy above, it's not a car except in theory. What about turning a car into an airplane? You can perform the inverse of the modifications above, an aeroplasty instead of an autoplasty. Wings! Propeller! Slow speed! Negative number of passengers! No more point in doing that than the reverse, so we're doomed, right?

In My Dream, We're Thinking About Flying Cars Right

Consider why you even want a flying car. There are plenty of cars and they're cheap. If you're commuting from your home to your place of striving, for example, you would have to drive your Chimera* from your home to the airport, take off from the runway, fly to your destination airport, land, and drive to work. Perhaps in some circumstances this will work, e.g., if the airports are very close to your termini and the distance between them is great enough to make the time saving of flying worthwhile. But even in that case, it would cost less and probably save time to keep a cheap car at both ends and fly an airplane much faster than your expensive Chimera with its bad aerodynamics. Of course, if the airports are at inconvenient locations or close together, you'll be better off driving anyway. The flying car of your dreams isn't the flying car the world needs.

Maybe I Should Finally Get to the Point

There's a company called Terrafugia that has been working on (and dreaming about) making a flying car since 2006. You still can't buy one, and if you take a look at their web site for the latest version, you'll see just how complicated it is. I assert that it is because they are trying to do too good a job: Good car, good airplane. As I mentioned (much) earlier, it probably can't be done at the current state of the art. At least not at a price anyone will pay.

What already exists is the useless good airplane/terrible car combo such as my Cessna 172. But if Tesla is interested, a good car/bad airplane combination could be a winner! By bad airplane, I mean slow speed, short range, and excessive fuel consumption. Who would want such an airplane? I would!

Why? Let me introduce you to something most New Yorkers learned in their youth:

The George Washington Bridge Song

Do you know it? It's easy to learn: listen here. In case the link disappears, here are the lyrics. (I learned other songs in my youth, too. The Element Song is much longer.)

The George Washington bridge is bilevular, the bottom deck being dubbed for obvious reasons "The Martha." It's only about a mile long and is an important link between New York City and New Jersey.**

You can fly across the Hudson River from New York to New Jersey in less time than it takes to sing the song. Even if you have a bad airplane with slow speed, short range, and excessive fuel consumption. And if your bad airplane is configured with four rotary wings like the common consumer drones, you wouldn't need a runway. Or, for that matter, the George Washington Bridge itself.

You Don't Have A Tesla S-Aero. Could You?

Only Elon Musk knows for sure. But is it too bizarre to contemplate? Sporting four retractable stalks with electric motors and propellers? I don't think it is. Of course it would take a lot of engineering and clever design, but given my design goals of short range and excessive fuel consumption, an inefficient design might not be impractical. Remember, our goal is a quick trip across the river or other local jaunt. If the car has a range of 300+ road miles when charged, would it be too much to ask it to go, say, 30 air miles? Or even just 10? That usefully covers a lot of territory, especially in a metropolitan area. And if it's in the air for only a few minutes, it doesn't need great speed, so automobile aerodynamics will be fine. Since it's only going a few miles, it doesn't need to waste time ascending to altitude and then descending. If it never goes above a few hundred meters, it's not going to interfere with airplane traffic, and so won't be the air traffic control nightmare it otherwise might be.

Sure, if one of the electric motors fails, you'll fall into the river or otherwise crash, so it will need at least one redundant propulsion motor with thrust vectoring, maybe two. But electric motors are small and have no complicated mechanical linkages that make helicopters and tiltroter aircraft the mechanical nightmares that they are. Our S-Aero might be a software nightmare, but Tesla will have a leftover legion of programmers when they're done with my suggestions in yesterday's blog.

I've picked an odd time to think about this. I haven't been trapped in GW Bridge traffic for over half a year. Or, for that matter in any traffic at all, since the roads have been empty. But if you've ever been stuck trying to get to the Bridge via its terminally congested feeders, you've probably wished for a flying car as much as I have!

Considering the above, the usual RIKLblog caveats apply. Along with epidemiologist, I can also spell aeronautical engineer, but I am neither. However, given how many people have been dreaming about flying cars, I bet there are plenty eager to get to work.


* Make it a brand name and the word does triple duty!

** Joke: Why are there two tunnels but only one bridge between NYC and New Jersey? Two out of three New Yorkers don't want to be seen going there.


 
2020
Richard Factor

NP:

"Flower of Love"

Baris Manco

 

 

ToTD

We went on a whale-watching afternoon cruise in San Diego a few years ago. No whales, but an unending pod of dolphins, so we weren't too disappointed.

Whenever I see a "Save The Whales" anything, I'm irresistibly reminded of the phrase: "Collect the whole set."


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