Where’s my flying car? Nowhere, and that’s a good thing

Recent events surrounding the Bird Platform have reminded us that Tech Bros, billionaires or otherwise, have limits to their expertise. It’s Tech Bros who have been pushing the urban air mobility idea, and have persuaded many that it’s the future. But then in a quick exchange on said Bird Platform the other day…

Literal flying cars have been designed, and even neatly engineered (Molt Taylor’s Aerocars), but fundamentally a car is designed to maneuver on a smooth or not-too-smooth, width-constrained surface, and on the reasonable assumption that they will run into things and must therefore protect their occupants, at a significant price in weight. Airplanes have wings and must be built light, and “let’s not crash in the first place” has been at the core of aerospace technology and culture for ever. The Aerocar was a small car that towed its airplane bits like a trailer, and why this was easier than driving to the local airport and getting into your Piper, Beech, Cessna, Mooney or whatever was not clear to me, nor to the tens of thousands of owner-pilots who did not buy an Aerocar.

UAM is different in that it involves aircraft that have car-like functions. They are sized for personal transport, and capable of VTOL so that they can perform point-to-point missions – no “staging” like a car to the airport. They are supposed to displace cars and reduce congestion, which means much lower operating cost than small airplanes and helicopters today, and an infrastructure that can support thousands of trips daily in a large metro area. That in turn means that they must be mass-produced on a scale that aviation hasn’t seen since WW2, and probably used in an Uber-type model that maximizes utilization.

Now stipulate that we can design and certificate a vehicle that will do the mission. We’ve still got issues.

Economics: Even if electric power and mass production makes a UAM vehicle relatively affordable (approximately light airplane price), it will either have a pilot – qualified to the point where regulators and insurers think they are safe to carry people for hire – or it will be unmanned. Yes, we ride in unmanned elevators, airport shuttles and urban railways. They run on segregated and protected tracks and are controlled in one dimension (linear speed). That is not what a flying machine does. It’s not the fuddy-duddy regulators you have to talk to – it’s your insurers.

Maintenance is another cost issue. Aviation survives on maintenance and inspection, done by well trained humans. Either the system pays for this – and starts heading toward private airplane costs – or it’s automated. (Your insurers are on the line again.)

Passenger experience: It’s always a calm, sunny, gin-clear sky in the land of UAM promo videos. As I write this, the sky over Northern Virginia is overcast, rain is falling, and storm cells are rolling through, and this is nothing unusual. We’ve all been in cars in heavy rain. Now imagine being in a ultra-light plastic bubble at >100 knots, rain hitting the windshield like machine-gun fire; ground, sky and other traffic all invisible. Add some hail. And turbulence. This is a passenger vehicle, not an ultrafast 6g roller-coaster for teenage fear junkies. Also, sooner or later your flying Cuisinart is going to fly through a flock of starlings, and the people on the ground will be even less happy about this than your passengers.

Infrastructure and environment: Not every urban rooftop will be a landing place. Large-scale operations with hundreds or thousands of daily trips into city centers will require some kind of coordination. High-level sites will have their own problems even in moderate wind. Recall that some city-center VTOL dreams of the past ran into reality – if the operation was to be economically sized, it needed frequent departures, which meant a ramp with space for multiple vehicles.

It was soon realized that adding a short runway to a facility like that did not make it much bigger or more expensive, which is why we ended up with the de Havilland Canada Dash 7 and (eventually) London City Airport.

The gorilla, though, is safety. UAM safety, from the first day of operations, has to be far better (hull losses per departure) than today’s light aircraft or helicopters. As Sikorsky exec Chris Van Buiten observed five years ago: “It’s 50,000 aircraft flying 3,000 hours each annually—a total of 150 million flight hours per year. If the world’s safest helicopter today is lost at a rate of one per one million flight hours and we are talking 150 million flight hours per year, can our industry tolerate 150 YouTube videos of moms not making it home? Never. Not going to happen.”

Van Buiten went on to say that the goal was achievable – but didn’t say what it would cost to make it happen from Day One with radical configurations and power systems, let alone unmanned. I’m not sure the lesson went home. I’ve recently seen a commercial VTOL tilt-rotor design with two rotors, one engine, and no auto-rotate capability. Lose one rotor, flip over and crash. The company’s fall-back? A whole-airplane parachute. That’s not going to fly with either the Feds or Flo from Progressive, nor should it.

What I don’t think that the UAM boosters realize is that the safety of large commercial airplanes these days is the result of 100 years of work in farepaying passenger aviation. Crashes happened, accidents were investigated, underlying causes found, and fixes were gradually implemented. Do we know how to reproduce that in an all-new system? Maybe Tesla’s self-driving capability is a lesson for us.

And a final point: what would a 150 knot personal commuter craft accomplish? Railway, streetcars and cars brought us suburbs. UAM could have implications far beyond the city limits, as the urban wealthy withdraw to enclaves off the road or rail grid or to natural or artificial islands. Today, it would be easy to envision those enclaves being defined by belief and culture as well as economics. So a half-successful UAM system – safe enough, but economically restricted to the Porsche classes – could have unintended consequences for society, far beyond its user group.

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