The emotional appeal of the flying car is something I don’t understand. Airplanes have been around for a long time, and they’re really good at doing what they do. Cars have been around even longer, and they’re even better at doing what they do, better, to explain, in that cars are supposed to stay firmly planted on the ground instead of fighting with all of its design might to avoid just that fate.
So when I go somewhere, I like to fly there, and then, once I’ve arrived, I just get a car to drive around. There are free or cheap cars just about everywhere I’ve ever flown. And with a couple of good car share apps on my phone, I can always just summon an Uber.
But, for some reason, many find the appeal of a flying car irresistible, to the point where a number of flying cars have been built, though only two of them ever produced, with only a few examples of each, at that. Several others are currently at various stages of development.
And with the rise in drone technology—another subject endlessly fascinating to people, and with some good reasons—it seemed inevitable that someone would comingle the flying car and drones and even go a step further, calling for a huge fleet of on-demand autonomous flying cars that customers can summon with the flick of an app and away you go. Simple! Right?
It’s not, and here’s why.
For starters: physics. We pilots know that it’s impossible to escape the realities of it (except in marketing meetings, of course). So let’s be generous and assume that the aero design works out and you’ve got a flyable craft capable of performing its mission—carrying a single person from point to point with close to 100% reliability. This is, of course, a huge assumption to make, but for the point of argument, we’ll concede that. Also for the sake of argument, let’s say that every customer will be a single person and not a couple, again a big concession. Let’s establish an upper weight limit of, say, 300 pounds.
Okay, so we need to envision a craft capable of carrying 300 pounds for, I don’t know, 10 miles with an endurance of at least an hour, probably more like 90 minutes, or even more when the FAA has its say, which it will. The Feds will be intimately involved in this because there’s a name for a drone that carries a person: “aircraft” and to be more exact “air carrier aircraft.” But to be charitable, we’ll stipulate 300 pounds and an hour.
Propulsion? Well, I don’t think the FAA will start certificating aircraft without giving the engine its blessing, so we’re talking about a certificated or to-be-certificated engine capable of carrying a 275-pound person. I say 275 pounds to apply a factor for passengers being optimistic about their weight. I supposed a weight-on-wheels sensor could ferret out the overly optimistic riders, but then again, autonomous drone customers would self-select as optimists to begin with.
For a close analog, let’s talk a Robinson R22, the best-selling two-seat helicopter ever. It makes use of giant blades and a 180 hp engine de-rated to around 130 hp, and it features a typical fuel payload of around 380 pounds. At a max weight of 1,370 pounds, that’s a pretty good analog, right. So our imaginary drone would need to be at least 80% as powerful, so, let’s say 110 hp, around the power output of a Lycoming O-235 piston engine, which is a popular engine for light airplanes. Of course, we wouldn’t use a piston engine at all, but a powertrain consisting of an electric motor or motors drawing current from a stack of batteries.
Let’s say that that combo of batteries, motors and props and supporting structure weighs in at the same as the fuel, prop and powerplant of the small piston engine I suggested, and we’re looking at a weight for the aircraft, occupant included, of around 1,000 pounds, and, again, I’m being generous here.
Which brings me to the next point: Where will these things fly? I’m going to assume it will be around city centers, because that’s where people want to go and want or need to be, as shown by the large number of people in cities every day. So for the flying Uber to make any sense at all, it would have to literally go to town.
So here’s the most optimistic scenario: a fleet of big, autonomously controlled flying taxis humming below rooftop level in bustling city centers carrying live humans. Hmm. They will, after all, have to land somewhere, right? But where that is, I have no idea and no idea about where to start figuring out where to put these landing zones scattered around the city for dozens or hundreds of these flying taxis. And it couldn’t be a single spot!that would defeat the entire idea of flying taxis. People want to go somewhere specific.
Even if we were to assume that the landing zone issue was solvable, what would these drones do when, not if, they have mechanical issues? Would they autorotate down sans power but props still spinning into the madding crowds of pedestrians below, a thousand pounds or more of whirring propeller blades? It’s not a pretty picture to imagine for the safety of pedestrians or vehicular traffic below. A whole-aircraft chute makes great sense, but only until you factor in the lack of suitable touchdown zones or the additional weight, which would require an even larger and more powerful machine than we’d hypothesized originally.
I could ask how today these problems are being addressed by other small flying aircraft, helicopters. How do they fly buzzing here and there low level in the big cities? But the question would be facetious. Nowhere in the world do helicopters fly in such a fashion, for the very reason that it would be a logistical and safety nightmare.
I’ll skip the mechanical obstacles, because it would be highly speculative, but suffice it to say that there will be no magic involved in getting this aircraft off the ground or keeping it flying.
In the end we’re looking at 1,000 pounds of metal, composites and lithium-polymer batteries tooling around the skies while avoiding wires, skyscrapers and other flying craft while dealing with the same kinds of complex weather phenomena that today’s aircraft deal with but in and among towering walls of stone, glass and steel.
This is all, of course, assuming that the FAA would give thumbs up to a single-power-source craft of a type never certificated before performing passenger-carrying commercial activities. For those of us who fly or know about flying, we can chuckle. It might happen, but not in my lifetime, and I’ve hopefully got a handful of good decades to go.
So I’m not worried about the safety of the flying taxi passenger public. They’re in no danger. This idea might generate publicity, as it has here, but in terms of practical products, it’s not going to happen.
There’s one really good thing it might do, though. Such development will very likely inspire new design ideas that could be used in practical aircraft to come, ones that fly much the same kinds of profiles as we fly today and not imaginary mission scenarios. That kind of research could do some real good.