After a hundred years and more of waiting, it is probably not far away at last – as long as you have a pilot's license and deep pockets.
Flying cars have haunted aviation since even before the Wright brothers first took to the skies in 1903. Gustave Whitehead, better known for his challenge to that First, had begun making flying cars some years earlier. He built a series of designs with two engines and folding wings, so that the smaller engine drove it along the road, its wings folded like a convertible car with its roof folded back. The idea was that the wings would be unfurled, the bigger engine started and off it would fly (Whether any of them ever succeeded is moot; that great aviation authority the Smithsonian Institution is under contract to deny any such claim, and fulfils its contract energetically. But that has nothing to do with their intended purpose as flying cars).
Since then many weird and less-than-wonderful prototypes and projects have gone to prove how hard it is to build one that works. However a few did succeed, and even see limited production. But on the whole these were pretty impractical. Most left something behind at the airfield, be it a trailer while they were flying, or the wings when they were on the road. Just a handful could genuinely drag their wings around with them on the road, be they fixed or rotary, and none was especially practical for daily use. Two which stand out, and also illustrate contrasting ideas, are Molt Taylor's Aerocar with detachable wings and tail (4 built) and, as a kind of aerial motor bike, Jesse Dixon's Flying Ginny roadable autogyro (1 built).
The endemic problem is that the vehicle must be capable enough for it to be certified and insurable both as a roadster and an aircraft, while the design compromises between flight and road requirements must inevitably restrict the capabilities of both. Much fiddling around is needed to convert between configurations, while the individual vehicle must also be routinely maintained, inspected and approved independently for each regime, if it is to continue in use. The driver must also be an expert pilot, if they are to handle its compromised flying qualities. What you inevitably used to end up with was a pile of timewasting trouble that was neither a useful aircraft nor a useful road vehicle.
But all that is changing. Modern materials, manufacturing techniques and digital flight systems are drastically changing the design compromises and the solutions available. Paul Moller deserves special mention for his lifetime of pioneering work on many of these technologies. His decades-long M400 Skycar project will probably never make it home, any more than his business acumen has, and he remains the butt of every critic. But from his 1970s Discojet through to the more refined M400 and its siblings, he identified and progressed many of the concepts and subsystems necessary to achieve the dream, from novel aerodynamic and power configurations to integrated and user-friendly flight systems and even regulatory regimes. He was among the first to discuss these issues actively with the regulators and help inform their own progress. Every project discussed below owes him an incalculable debt.
Since the Millennium, activity has exploded. Any self-respecting dot-com playboy with a few billions to splash around has been developing their own concept and prototypes, while aerospace professionals are finding it relatively easy (or should I say less impossible) to attract venture capital. Interestingly, it is the professionals who are beginning to get their products certified. Where the dot-com kiddies focus on the elusive autonomous VTOL dream, the pros are taking it a step at a time and going for more conventional flight and avionics solutions. You will still need a pilot's license as well as a driver's, and lots of paperwork, but that viable flying car is at last within sight.
Certification takes a lot of time and money, and you never know when something might throw up a problem and have to be rethought. For road certification, several examples have to be built and crashed-tested. At the same time, adequate strength to protect the occupants has to be built in without adding undue weight compared to an aeroplane. In some cases the airworthiness requirements do not exist and a certification authority has to be engaged with in order to develop a new standard. Even when established, certification flights can take years to complete. Covid lockdown did not help.
As yet, no modern design has been approved for both road and air use. Several did achieve certification for the one or the other over the last few years (No, contrary to certain hype merchants, I don't count Experimental certification allowing only limited flight testing). All fly as pusher aircraft, with a single rear-mounted propellor powering flight. Some have gone bust and only two are still in the running after several years of grinding through the cash-draining certification process. One is an Aerocar type that keeps its wings with it, the other a Flying Ginny on steroids. Setting aside the overoptimistic ambitions of the two companies, here is my best shot at their running order, listed in reverse.
2. Klein Vision AirCar: Slovakian Stefan Klein has produced a car with the popular twin-fin rear seen on several others, and unusually neat foldaway wings. It gained flight certification in January 2022. If it can get that road approval through too without any major issues and if Pal-V stumble at the last hurdle, it might just pip them to the post.
1. Pal-V Liberty: This roadable autogyro is intended to be the initial production version of the Dutch PAL-V. It is the only three-wheeler of the pack, and actively leans into corners on the road to make up for the reduced stability that brings. As with the others it has an enclosed cabin, twin tail and retracting/folding wing, albeit a rotary one; a notable advance on Jesse Dixon. It is not widely appreciated that the autogyro is the most compact and lightweight way to get you into the air, and spinning up its rotor under power before takeoff can potentially bring "jump" VTOL performance for the skilled pilot. In an opposite move to its main competitors the Liberty is now street legal but has yet to be certified airworthy. That might sound a note of alarm, except that the airworthiness work has also involved cadging new standards out of the EU authorities and the two organisations have been cooperating closely for some years. The Liberty incorporates modifications to a previous prototype, as requested by those same authorities to meet their new standards, which were only finalised early in 2022. Design and pre-production of the Liberty tracked them closely, so few if any changes were subsequently necessary. Final certification has been running for about a couple of years now. This puts the Liberty ahead in the certification race; it is looking good to win.
Meanwhile the dot-com visionaries and other players must look further ahead for their ambitious dreams. Electric power is already appearing in road cars and even the odd light aircraft, but has yet to make it into a realistic flying car. Nevertheless, the vehicle's comparatively low-power and short-distance regime is ideal for it and it must surely come. It liberates the aircraft designer in many ways, which has led to a rash of crazy prototypes, some of which may yet change the way we think about powered flight. Distributed propulsion, as seen for example in Germany's Lilium Jet, is creating a real buzz (sic) and is one to watch. The case for a multitude of lifting rotors is harder to justify, despite the dot-com fondness for them. Meanwhile, perhaps goaded a little by Lady Gaga's notorious indoor Flying Dress, the FAA has already drawn up regulations for a class of aircraft it calls the Personal Air Vehicle. However it is the most basic electric-powered urban passenger aircraft, the piloted eVTOL "air taxi", that has been grabbing the headlines recently. Until that goes into service, anything more revolutionary is going to have to wait.
That has not stopped the autonomous-AI enthusiasts from launching a similar rash of projects for unpiloted air taxis and family-friendly flying cars. Besides the daunting challenge of an AI safer than a human pilot, the potential explosion in adoption of these things in an urban environment creates huge headaches for air traffic control and emergency landing sites. In some areas relatively congested with light aircraft, a ground-based automatic distributed system already collects and maintains live flight data on every aircraft it can see, and the wise pilot has a gadget which talks to it and warns him of any danger zones near his flight path, so he can steer clear of them. The FAA are again working hard to create the necessary ground infrastructure and regulatory environment for high-volume autonomous air traffic; it seems likely that developments of these distributed systems will feature strongly. It is harder to say which will come first, the autonomous AI flying car or the intelligent city it is allowed to fly into.
But neither revolutionary design nor autonomous systems is anything more than an experimental pipe dream as yet. Don't believe the hype; I for one am not waiting up. The first generation of flying cars will remain a niche product for the well-heeled and well-qualified pilot.
Updated 3 Feb 2024