“It is not sufficient to implement an eVTOL service by simply substituting it for helicopter service in the future.” That was the warning from Denis Heckmann of FEV Consulting as he delivered his analysis of prospects for urban air mobility (UAM) services in Dubai during the recent Vertical Flight Society Forum 76 conference.
Back in 2017, Dubai’s Roads and Transportation Authority (RTA) began conducting air taxi demonstration flights using early prototypes of eVTOL aircraft being developed by Germany’s Volocopter and China’s EHang. The ambitious city-state, which is part of the United Arab Emirates, set a goal of making 25 percent of all traffic self-driving by 2030, including air taxis. However, since then Dubai’s UAM plans seem to have gone quiet, with little further progress evident.
According to Heckmann, for an air taxi system using eVTOL aircraft to be effective, it must integrate with any existing multi-modal system to provide first- and last-mile service, as well as having public acceptance, adequate throughput, and sufficient demand. The key to acceptance, he said, is that the service clearly add value in terms of passenger time saved and optimized pricing.
“You have to increase the number of passengers, speed, and frequency to achieve optimization,” Heckmann maintained while warning that “higher speed and loading requirements increase energy and power demand and recharging times impact ground handling and infrastructure.
"It can reduce availability and increase overall costs," he continued. "Increased throughput requires not only an efficient aircraft design but also a highly capable battery and operations concept to increase system utilization.”
A location's environment can also drive costs. The intense heat in Dubai during summer, when the average daily temperature often exceeds 98 degrees F, requires the construction of protected parking pads and aircraft with robust air conditioning. The former consideration increases construction costs and impacts takeoff and landing patterns, while the latter adds to overall aircraft power consumption and constitutes a weight penalty.
Price considerations for associated vertiport structures is also a key cost driver, Heckmann stated. Constructing landing pads on top of high-rise buildings is not only expensive but can add significantly to total travel times as passengers navigate their way in and out of these structures.
“The overall price for the space is very important," Heckmann said. "Retrofitting of buildings can be very effortful if feasible at all. And that has to be taken into account." In his view, while vertiports on top of low-rise parking structures or at ground level can be more cost advantageous, they can drive a requirement for more vehicle speed and also increase first- and last-mile costs and time requirements.