The terms eVTOL, AAM and Air Taxi are currently unfamiliar to many people. The following Frequently Asked Questions explains various words, phrases and acronyms currently used when discussing aspects of the eVTOL Air Taxi industry. It also answers some common questions in relation to using eVTOL Air Taxis.
The same is true when transitioning from thrust-borne to wing-borne flight and back again as the aircraft passes through the threshold at around 60kt to 70kt. And once the airspeed is sufficient for the wing to generate all of the lift with a safe margin from wing stall, the flight-control computer automatically stops the aft propellers.’
¹Source.
eVTOLs have been designed to have a dramatically quieter noise profile than a helicopter. In fact according to NASA acoustic testing², the Joby S4 was found to be approximately one hundred times quieter than a typical helicopter. NASA recorded the Joby S4 at 45.2 dBA when flying 500m over head, and 65 dBA from 100m away on takeoff, so when cruising it may not be noticeable above typical urban background noise. If you imagine that many car vehicles tyres are rated as 70 dBA, a Joby S4 on takeoff or landing may well be quieter than a vehicle driving along a nearby road.
Due to their design utilising electric motors, eVTOLs are much easier to assemble and service than a traditional helicopter which requires many parts, including but not limited to a fuel injector, exhaust system, coolant and lubrication system. Given the design advantages, Archer Aviation is aiming to be able to manufacturer its proprietary motors in twenty minutes. Given this and other advantages, operational servicing costs for eVTOLs are expected to be considerably less than traditional helicopters.
Traditional helicopters, according to some, are one of the most dangerous forms of travel when looking at total miles travelled. eVTOLS from Vertical Aerospace are currently anticipated to have a safety profile akin to the commercial airline industry which is the safest mode of transport by miles travelled³. If that is achieved, it will be significantly safer to travel by their eVTOLs than by car. Their eVTOLs are expected to operate at such an exceptional level of safety due to highly redundant architecture including through the use of multiple power supplies and motors.
¹Source.
²Source.
³Source (34:27 onwards).
Efforts are being made to automate production where possible to facilitate high volume scale production, including in areas such as aircraft composite parts manufacture (e.g. fuselage), adhesive application and curing as well as welding.
However some aspects may remain a manual process as according to a FlightGlobal article¹ in relation to Vertical Aerospace ‘certain parts of the process will always remain manual, where either automation is too expensive or for tasks where ‘sometimes people are just better’.’
¹Source.
Vertical Aerospace expects to replace battery packs when the pack eventually falls to 92% of the original modelled energy capacity (i.e. once recharged). Therefore the frequency of pack replacement will depend upon how the aircraft is used and maintained.
Automated traffic deconfliction, in order to avoid collisions, is a stated goal. For example according to Britain’s Advanced Mobility Ecosystem Consortium, involving Britain’s National Air Traffic Services, the following roadmap has been outlined…
‘2025-2030 – New categories of airspace established with Integration of AAM services and manned ATC systems. Drive towards automated traffic
deconfliction within the service to increase efficiency and reduce reliance on manned systems.
2030-2040 – Full scale, integrated and autonomous service to manage high airspace utilisation. Route network expansion, connecting regions to provide an inter-connected, highly digitised transportation service to all.’¹
ATC: Air Traffic Control.
¹Source.
I should probably also add Double Bubbler to that list!
It should be noted that the AAM market is a nascent industry and as such investing in participating companies could be considered high risk. I personally have invested money that I can afford to lose given that could be the worst case scenario in my opinion.
Disclaimer: This FAQ is for my personal reference and may be subject to errors and or omissions. You should do your own independent research or seek professional advice to corroborate or refute what I have presented. All information presented is based on my interpretation following research at the time of writing each FAQ answer.