Brian Garrett-Glaser
By Brian Garrett-Glaser

As the managing editor of eVTOL.com, Brian covers the ecosystem emerging around eVTOLs and urban air mobility. Follow him on twitter @bgarrettglaser.

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UKRI study highlights the need for high occupancy rates in future air taxi services

A socioeconomic study of six potential use cases for drones and air taxis commissioned by UK Research and Innovation (UKRI) found significant opportunity for time and cost savings via the use of drones, but its conclusions for some potential use cases of air taxis were less clear-cut.

UKRI Future Flight Challenge
The £300 million Future Flight Challenge is investing in air taxis, drones, and other new aviation technology. UKRI Image

The study, conducted by consultancy PricewaterhouseCoopers (PwC) and funded as part of UKRI’s £125 million ($170 million) Future Flight Challenge program, analyzed three uses cases each for drones and air taxis, estimating costs in comparison to current activities. Without providing a specific timeline, all applications were studied assuming “an incremental uptake” in the use case with the expectation that more widespread adoption is likely to reduce capital costs or improve utilization/occupancy rates as economies of scale take effect.

“UK Research and Innovation commissioned PwC UK to undertake a study to develop a holistic framework that can be used to assess the potential costs and benefits of certain use cases selected by the [Future Flight Challenge],” the report states as its purpose.

For drones, the three use cases studied were:

  • Power line inspection using VTOL drones with beyond visual line-of-sight (BVLOS) flight
  • Mail cargo delivery across water using a BVLOS, hydrocarbon-powered fixed-wing drone
  • Last-mile delivery of prescribed medicines using autonomous battery-powered drones, with one pilot monitoring 20 drones

All three of these cases are representative of drone applications frequently discussed and currently pursued by companies in the space. In each, the report’s authors found significant cost reduction was achievable — up to 35 percent in the case of mail delivery over water, with the Scottish route of Inverness to Kirkwall used as an example.

UKRI-PwC conclusion on drone inspection

For power line inspection, 34 percent cost savings were expected for surveying 615 towers along a chosen 2,200-kilometer (1367-mile) power line, with the added bonus of completing the work in 22 days rather than 62.

The air taxi applications selected for analysis by UKRI were defined as follows:

  • Sub-regional air taxi connecting destinations without direct train service, using a battery-powered eVTOL with 12 seats to travel about 100 km (62 mi)
  • Rural air taxi traveling 25 km (16 mi) between towns using a battery-powered eVTOL with four seats
  • Urban air taxi traveling 10 km (6.2 mi) within a city such as London using a battery-powered eVTOL with four seats

For both the rural and urban air taxi use cases, UKRI’s socioeconomic study found the new technology will cost more than business as usual — for rural trips, driving a car; for urban trips, hailing a rideshare vehicle — with some important caveats. Both use cases assumed an average occupancy rate of 33 percent, filling just one of three passenger seats; when occupancy rates were doubled, the urban use case became much more promising.

Rural air taxi applications assumed passengers spent 10 minutes traveling to and from vertiports as part of their trip, resulting in little time saved. Urban trips assumed a five-minute walk on either side of the journey and are expected to save passengers about 30 percent of their travel time for a fare increase from £15.62 to £26.52 ($21.39 to $36.32) — a reasonable tradeoff some business travelers might make. With a second passenger added, the fare drops to £13.26 ($18.17), which is less than a typical rideshare vehicle today.

UKRI study urban air taxi
The sensitivity analysis seen here demonstrates the outsized impact of occupancy rate on the economic case for urban air taxis. UKRI Image

The economic results presented by the UKRI study for these two use cases underline the necessity of achieving high utilization rates for future air taxi services, a conclusion noted in the October 2016 Uber Elevate white paper. Its authors noted that the efficiencies and utilization achieved through the ridesharing model are critical to the success of on-demand eVTOL transportation, selecting 67 percent occupancy as their base expectation.

A spokesperson for the Future Flight Challenge told eVTOL.com a 33-percent occupancy rate was considered the most likely over the “near-term” period and reflects current business-as-usual occupancy rates, referring to car and ride-hailing usage.

Air metro: economically attractive, but not technically possible in the near-term

The final use case selected by UKRI for study presented the most promising economic and time improvements over current transportation options, but also relies on technology far beyond current capabilities. The study’s sub-regional air taxi application assumed a 12-seat battery-electric eVTOL would move commuters more than 100 km (62 mi) between towns that don’t have a direct train connection, thus saving passengers almost two hours each way. The base case assumes a 55-percent utilization rate, or six seats filled.

With fares only slightly higher for the air taxi commute than the multi-train journey, UKRI and PwC concluded this application would save commuters more than £60 ($82) in time each trip, calculated based on figures released by the UK Department of Transport. And that’s assuming train passengers have purchased a “commuter pass” — if single-day tickets are purchased, the air taxi becomes less than half the fare price of the train.

“We considered that this scenario would be interesting to investigate and would offer a valuable contrast against the smaller air mobility vehicles with their limited range,” the spokesperson told eVTOL.com, adding that assessing technical feasibility was outside the scope of the paper. “That said, there are examples of companies who wish to pursue this type of configuration.”

FFC feasibility study
A consortium led by Atkins, including UK companies Vertical Aerospace and Skyports, was recently awarded £2.5 million through the Future Flight Challenge to study the feasibility of an air taxi service in South West England. SNC-Lavalin Image

While some companies are pursuing electric fixed-wing aircraft capable of flying higher numbers of passengers, a battery-powered VTOL aircraft with the range and payload to fulfill UKRI’s use case is likely decades away. The largest eVTOL prototypes now in flight testing are expected to carry a pilot and four passengers — and are already pushing the limits of what is possible with today’s cutting-edge motor, composite structure and battery technology.

But perhaps the greatest barrier to the operation of a 12-seat eVTOL would be noise. At the 2020 Electric VTOL Symposium hosted by the Vertical Flight society, JoeBen Bevirt, founder of Joby Aviation, was asked following his keynote presentation about the barriers to building larger eVTOLs and cited acoustics as the primary challenge.

“In terms of aircraft size, you can certainly build larger [eVTOL] aircraft, the larger the acoustics challenges and the more of an aggregation challenge there is,” Bevirt said. “In my view, it will be only niche markets that are served by significantly larger aircraft. But the market will figure this out.”

Mark Moore, former chief scientist for Uber Elevate, told eVTOL.com in an email he also saw noise as an extremely difficult hurdle for a 12-passenger eVTOL to conquer.

“The choice of a 12 passenger eVTOL for their sub-regional use case isn’t justified and seems somewhat random,” Moore said. “Other constraints are also critical in the considerations across all these markets, such as how much noise these aircraft make. The fact is that no eVTOL developer is trying to build a 12-pax because the noise would be far too loud to conduct operations in almost any city.”

If these challenges are solved, however, UKRI’s study demonstrates the potential of an air metro-like eVTOL service — something which J.R. Hammond, founder of the Canadian Advanced Air Mobility Consortium (CAAM), told eVTOL.com his organization’s stakeholders are keen on exploring as well.

“We at CAAM are committed to identifying how the AAM industry can continue to expand to be a more inclusive and equitable mode of transportation,” Hammond said. “One of the leading aspects Canada is committing to in terms of AAM use is through the Air Metro concept, i.e., moving larger quantities of people with less frequent flights from multimodal (ground and air) transport hubs.”

Without multiple breakthroughs in battery technology, however, such a vertical flight air metro system would likely have to be either hybrid-electric or employ hydrogen fuel cells — each of which present their own challenges for design, economics and adoption.

Editor’s note: This article has been updated with additional commentary by Mark Moore, and to clarify that the UK government funding available through the Future Flight Challenge totals £125 million. The £300 million figure includes expected industry match.

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  1. The pilot + 4 passengers model seems to be the most popular. The advantage is smaller craft which are more manoeuvrable within cities, and this model can borrow from existing ground-taxi passenger service algorithms.

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