Where is my flying taxi? The current status of vertiports

Movies like Blade Runner, Back to the Future Part II, and The Fifth Element led us to envision a future with flying cars. In this utopian vision, we could hail an air taxi to soar through the sky and travel on multi-level highways. There were even traffic jams. However, flying cars never truly took off, and now lighter vehicles are emerging as an alternative for transporting goods. Why don't we see flying cars, and where is local air transport heading?

There have been literal attempts to attach wings to cars. Yes, that's right, wings to cars. Two notable examples are the 1947 Convair Model 118 and the 1971 AVE Mizar. These designs featured conventional cars outfitted with a light aircraft structure on top, lacking a cabin. Back then, the automotive industry held out hope for advancement, but the laws of physics (and society) didn't permit their widespread adoption.

Cars stuck to the ground for many reasons, but among the most important were that flying a light aircraft required much more complex training than driving a vehicle, that not everyone could have an airfield close to their home or work, or that the likelihood of destroying the axles on landing was only slightly less than that of breaking the wings. After several prototypes, tests and more than one impact with the ground, these models were discarded.

The wheel is simple. There are stones that roll downhill or are carried away by air currents. But none fly, because hovering in the air requires the use of enormous amounts of mechanical energy. Flying is much more expensive than rolling and requires considerable fuel consumption (and energy in general).

When the first winged cars were planned, fuel consumption was another obstacle to overcome. As vehicles with propellers are now being explored, electric power presents its own challenges. First off, flying a drone (whether autonomous or not) consumes tens to hundreds of times more energy than driving a car (again, whether autonomous or not). This significantly increases costs, both financially and environmentally.

Additionally, the limited energy density of batteries restricts drones' range. People are unlikely to want to board a quadcopter with a range of just half an hour,

making the situation complex. Besides the technical issues, which are still being partially addressed as outlined below, legal challenges remain to be tackled. Among the challenges currently being addressed are:

• Increasing the energy density of batteries. In 1991, long after the AVE Mizar concept was shelved, battery energy density was about 100 Wh/kg. By 2023, it has surpassed 500 Wh/kg. This progress offers hope for short peri-urban journeys, although urban trips will still face legal hurdles.
• Lighter materials and designs. While cars from the last century used steel and wood, and those today incorporate plastics, we've now developed materials that offer both high strength and low weight. Examples include carbon fiber used in Formula 1, aluminum alloys from the aerospace industry, and fiber-reinforced polymers found in water sports.
• A driverless taxi weighs less, which is advantageous. From an engineering perspective, transporting a vehicle weighing several hundred kilograms plus an extra 80 kilograms for the driver to move one person is not very efficient. Any method to reduce the cabin’s weight is beneficial, and autonomous flying is already a staple in aviation.

However, two major legal challenges remain:

• The complex (and essential) air regulations. Airspace is heavily regulated for obvious reasons. This is why many drones cannot operate in urban areas, —there is a risk of falling. If drones weighing just a couple of kilograms are regulated, flying taxis will face even stricter regulations. Certification is also a contentious issue, particularly concerning autonomous taxis.
• Considering civil liability is crucial if something goes wrong, and so far, neither lawmakers nor insurers have accepted the risks associated with a car potentially falling from the sky. While car insurance averages around 600 euros in countries like Spain, an air taxi policy could be ten to a hundred times more expensive, depending on the flight altitude.

Air taxis, perhaps even autonomous ones, are likely still a decade or more away. The challenges they face are significant, and there are viable alternatives to flying, such as driving, using public transport, cycling, or walking. Or even combining all of these options. However, there are sectors where 'flying mini-cars'—known as UAVs (unmanned aerial vehicles)—have a more immediate future.

One of the best Swiss inventions of 2023, for instance, was a heat-resistant drone designed to assist in firefighting. This UAV can perform aerial reconnaissance, lift fire hoses to the upper floors of tall buildings, and drop 'extinguishing bombs'. For several years, some beaches have been using maritime rescue drones that can deploy floats, send warning signals, and even perform rescues.

In regions that are hard to reach due to landslides, heavy snowfall, or a lack of roads, many rescue departments are now using drones to deliver essential emergency supplies like fuel, blankets, food, and communication devices. In the skies above certain urban outskirts, where there are no people below, delivery companies have been testing parcel deliveries using drones for some time. This is likely one of the most immediate applications for flying vehicles.

All the data on innovation, technology, legislation, and social perception suggests that people won't be flying in air taxis anytime soon, aside from some impressive renders or pilot tests in countries developing these technologies. The challenges these vehicles must overcome are far greater than the heights they can currently reach.

However, when they finally are ready, a new infrastructure for loading, take-off, and landing will be required, already informally dubbed a vertiport. It's similar to an airport or heliport but designed specifically for drones, initially for transporting materials and eventually for passengers. Science fiction has set a techno-optimistic horizon that will take quite some time to reach, yet it already suggests probable futures with a degree of realism.

There are pilot vertiports where winged drones, resembling glider planes, are being launched to deliver vaccines to remote areas. Meanwhile, major logistics companies have begun searching for urban sites suitable for building landing infrastructure, in anticipation of favorable regulation.