AOPA Pilot Magazine - October 2019 - 64

routes that use GPS fixes. This would
require air traffic control for sequencing and separation of flights, but with a
special emphasis on the airspace below
1,000 feet agl. Embraer put out a white
paper-Flight Plan 2030-that expands
on eVTOL air traffic control, suggesting that current government-run ATC
services may not be well-suited for
eVTOLs. Instead, each city or nation
could have its own Urban Airspace
Service Providers (UASPs) that would
serve the en route phases of flight;
separate Urban Air Mobility (UAM) providers would manage skyport/vertiport
arrivals and departures.
What's not mentioned is the need
for surveying and charting this lowaltitude environment for obstacles and
clear signal reception at a very dense
scale. These charts would then be used
in the cockpit on a multifunction or
other electronic display, along with digital weather information.
Both Embraer and Uber hint
strongly that air traffic control services could be a privatized function,
run by Uber itself or some other nongovernment provider. If this path is
taken then the private service providers will most likely need to coordinate
air traffic flows with an already-established government-run ATC, especially
in urban areas served by existing airports. Conventional air traffic may use
arrival or departure corridors that cross
the routes used by eVTOLs. Helicopter
traffic will also use the same airspace as
eVTOLs, and so would package-delivery
drones if current projections hold up.
If eVTOL traffic counts rise outside
of urban areas, then presumably the current ATC system would handle it. But
given that eVTOLs operate primarily in
low-altitude airspace, ATC surveillance
radars may not always be able to detect
and separate them.
Embraer's idea of a typical urban
flight would begin with a flight authorization-a slot-for an eVTOL departure
issued to the pilot, who then takes off
into a cruise segment. En route, a
cooperative arrangement of on-board
traffic detection and UASP surveillance
monitors the flight-which follows GPSdefined legs-and looks out for traffic
and adverse weather. Any messages to
the cockpit are sent via digital messages
(like today's controller-pilot datalink
64 | AOPA PILOT October 2019

communications technology). Skyport/
vertiport personnel clear the eVTOL to
land, ensuring that there are no weather
or other hazards, and assigning a specific landing pad. After landing, the pilot
sends a confirmation of landing, which
is shared with all network users.
ME-FLY IN THAT?

It's exciting to think about the possibilities of eVTOL flight, especially the
airborne UberX idea. Who wouldn't
trade an hour's drive in stop-and-go
traffic for a 15-minute flight above
it all? And what pilot wouldn't like
to cruise, nap-of-the-earth style,
over beautiful scenery in his or her
own eVTOL? It's safe to say that the
demand is there, but the level of that
demand is a question mark.
Major unknowns lurk over eVTOLmania, which is currently in its
youthful-exuberance phase. Battery
endurance still leaves a lot to be
desired. Uber says its flights should
land with battery reserves equal to
30 minutes of flight time, like today's
VFR fuel reserves-but current lithium-ion batteries may last only 30
minutes. Vertical takeoffs draw huge
amounts of electrical power, and precious little may be left for the rest of a
flight. Battery technology has made big
strides lately, but it has to come even
further to make eVTOLs practical.
Those vertical takeoff and landings
are also noisy. The noise is of a high frequency, quite unlike the low-frequency

noise made by helicopters. Most dislike
higher-frequency noise, so eVTOL operations may be a big nuisance for many
neighbors. And passengers.
This brings up the biggest potential
roadblock of all to mainstream eVTOL
flying: public acceptance. To most, they
look fragile and sound drone-like. They
are new and fanciful-looking, like something a 10-year-old would draw. The
average individual becomes concerned
at the thought of flying in one. Is it safe?
they think. Uber says that eVTOLs need
to be safer than driving a car on a fatalities-per-passenger-mile basis. Is that
reassuring? Perceptions are often based
on gut-level reactions. Yes, the earliest
of early adopters will sprint to eVTOLs,
cash in hand. As for the rest of us, we'll
wait and see: eVTOLs will only achieve
broad success if pilots and passengers
perceive that they have a level of safety
equivalent to that of certified aircraft.
Even with that assurance there will
be skeptics. Uber-which is setting the
trend so far-states that its ultimate
goal is autonomous flight. That means
completely automated flight, from takeoff to landing, with no pilot aboard.
Now imagine John Q. Public stepping
aboard a craft about to cruise above a
city. Inside are four seats, and a pilot
nowhere in sight. Will he trust the automation, or turn around and leave? The
future of intra-urban eVTOL air taxis
rides on the answer.
AOPA
EMAIL tom.horne@aopa.org
AOPA Pilot Magazine - October 2019

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