The Future Dominator of Chinese Sky: eVTOL

On April 7, Yihang Intelligence's EH216S unmanned manned aircraft received production license from the Civil Aviation Administration of China , making it the world's first eVTOL aerial vehicle to receive a production license. eVTOL aircraft's success represents a new chapter in the application of UAVs in low altitude. It is the beginning of a new chapter in low altitude application.
April 29, 2024
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Zhang Zhonglin
Aviation industry commentator

1. What is eVTOL?

With new energy vehicles in full swing, many people naturally ask: when will we see new energy airplanes? Especially the electric airplane?

In fact, research on new energy aircraft has long been underway, but face the following problems: the battery’s energy density is too low, the range is short, the dead weight brought by the battery is too large, and unlike fossil-fueled aircraft, they can consume the weight of the fuel in flight in order to reduce the landing weight.

Also for this reason, although the major aircraft manufacturers have exploratory research on electric fixed-wing aircraft, there are no actual products on the ground due to the above reasons, and the main R&D direction for new energy fixed-wing aircraft is placed on hybrid electric aircraft.

However, for eVTOL aircraft based on multi-rotor technology, the battery, weight and range problems plaguing fixed-wing aircraft are acceptable, because eVTOL aircraft do not need to perform thousands of kilometers of flights like fixed-wing aircraft, but rather short-range flights, and the use of the scene is mostly for urban low-altitude flights, which can be sufficient to take advantage of the strengths and avoid the shortcomings. The EH216S, which has just obtained three certificates, is such an eVTOL based on urban low-altitude flight.

If you look at the parameters of EH216S, you will find that it is not very big: the height of the fuselage is 1.93 meters, the width is 5.73 meters, the maximum take-off weight is 620KG, the maximum load is 220KG, and the maximum range is 30KM. 16 motors and 16 pairs of paddles are used for powering the EH216S, which belongs to the multi-axis aerial vehicle.

The EH216S’s vertical approach capability requires a small take-off and landing site, which makes it possible to utilize rooftop aprons, parks, etc. as a take-off and landing site in urban environments where land is scarce and the area taken up by constructing a dedicated take-off and landing site is not too large. For this reason, after the EH216S received the airworthiness license from the CAAC, the Air Traffic Operation Demonstration Center (ATODC) was launched in Bao’an District of Shenzhen to explore the operation mode of eVTOL in the low-altitude economy.

Although eVTOL aircraft are called “air cabs”, they are fundamentally different from cabs on the ground. The most fundamental point is that the cab’s boarding and alighting place can be regarded as basically free, and you can get off anywhere as you like. However, eVTOL air cabs cannot take off and land in unprotected places, and can only take off and land in dedicated take-off and landing sites, which poses a great limitation. eVTOL’s most ideal use scenario is to reach the destination directly from the air in the case of ground traffic jams, but its need for a dedicated take-off and landing site predetermines that there will not be a lot of places for boarding and disembarking passengers.

At present, many high-rise buildings have helicopter pads for helicopter landing and takeoff, which is technically possible for eVTOL to take off and land. However, the convenience of using the rooftop of a high-rise building as a drop-off and pick-up point is obviously not enough unless the destination happens to be that high-rise building.

Parks and other open spaces are naturally suitable for eVTOL takeoffs and landings, but setting up dedicated takeoff and landing sites will obviously take up parks’ space, and often not the final destination still needs to be reached via the ground. Therefore, at this stage, the most suitable for eVTOL application is still in the dedicated landing site as an urban air tour program.

2. eVTOL competition between the United States and China

The concept of eVTOL aircraft has been popular in the West for over a decade and is a hot topic in the aviation industry. While China is issuing its first eVTOL aircraft airworthiness certificate, Joby Aviation’s S4 eVTOL aircraft is also in the process of applying for an FAA airworthiness permit, entering the third of five phases, and the FAA has just determined Joby Aviation’s final eVTOL airworthiness standards in March 2024, which is still some distance away from obtaining an airworthiness permit.

It should be noted that the Joby Aviation S4 eVTOL vehicle is currently in the airworthiness validation process in the U.S. uses a configuration that is very different from the EH216-S, which is a tilt-rotor eVTOL that is closer to a traditional fixed-wing vehicle. Since part of its lift is generated through the wings, it makes its energy utilization more efficient. And with a crew of 4+1 (including a pilot), a range of 160km, a maximum takeoff weight of 2.4 tons, and a maximum speed that can reach 322km/h.

Larger range and larger number of crew, making Joby Aviation’s eVTOL has a larger application scenario, can meet from the airport takeoff directly to the downtown CBD area roof apron of this high-end business application scenarios, effectively replacing the helicopter’s function.

Although it seems that Joby’s S4 evtol has superior performance, the fundamental difference between the two is that Joby Aviation’s S4 eVTOL is manned, while the EH216-S is unmanned. This means that the latter can utilize the limited payload more efficiently and save on handling systems, while the unmanned application also represents a lower cost of use.

In other words, what we put into use that the U.S. does not currently have, what the U.S. has we also have and have more potential. And for eVTOL this new thing, explore its use and operation mode is the most important, and this is dependent on who started earlier, policy support is stronger, earlier to find the right business model.

3. eVTOL’s application prospect and industrial development

For eVTOL, its biggest advantage is that it can cross the limitations of geography and traffic conditions to achieve the purpose of rapid transportation. However, as mentioned above, if it is used for urban transportation, it is not so convenient to reach the final destination. Moreover, as an eVTOL flying over the city, it has to take into account the risk of crashes, which will inevitably occur in densely populated cities, and the paddles will also bring large casualties on the ground. Therefore, from the current stage, eVTOL urban transportation scenarios are more suitable or in the formation of cities or metropolitan areas around wide waters, and there is no bridge connecting the two sides of the scene for application.

In addition, city sightseeing tour is also a feasible scenario, firstly, the take-off and landing sites are all in the same without considering the factor of arriving at the final destination, and secondly, the flight routes of air sightseeing tour are relatively fixed, and the routes on the water surface can be selected to avoid the risk on the ground.

However, urban air transportation, air excursions in the foreseeable future is still a more limited demand, the need for demand is actually not high. The cross-bay, cross-river transportation is a practical application scenario and has a unique and convenient advantage over other transportation modes, but due to low passenger capacity of the current eVTOL vehicle, it can only be used as a supplement to cars.

However, eVTOL’s advantages of crossing geographic barriers and having smaller take-off and landing sites have broad prospects in other geographic environments. For example, in the mountainous terrain of southwest China, if you want to go from the foot of the mountain to the top of the mountain, you need to go through the mountain highway, which takes a few hours not to mention the risk is also high. But for eVTOL aircraft, they would only need ten minutes to reach the destination.

In addition, islands are also a very suitable for eVTOL. For archipelagos, transportation between islands can only be carried out by boats and speedboats. However, for islands, eVTOL is a faster and more convenient means of transportation between islands. eVTOL’s low passenger capacity is not a problem in the face of low traffic flow between islands. Moreover, since the eVTOL uses electricity as its energy source, the photovoltaic and energy storage facilities installed on the islands will make the eVTO self-sufficient to a certain extent in terms of the power it needs.

At present, the biggest limitation to the eVTOL vehicle is still the battery. The key technology of eVTOL is highly similar to that of electric vehicles, so much so that some electric vehicle manufacturers have entered into the manufacture of eVTOL flying machines.

And thanks to the rapid progress of the domestic EV industry in the past two years, lithium battery technology is also rapidly changing, and it looks like in 2025 it will be able to start applying a large number of semi-solid/full-solid state batteries. For EVs, the high cost of semi-solid/all-solid-state batteries is difficult to bear. But for eVTOL vehicles, which are often priced in the millions, the added cost of semi/full solid state batteries is perfectly acceptable, as the benefits (payload, range) far outweigh the extra cost.

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Zhang Zhonglin
Aviation industry commentator
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