In 2030 in New York it will be possible to move with an air taxi?
The question was asked by the AIAA that is the American Aviation Society,
that through a call for tenders, a student design competition,
so a request for students
mainly obviously of aeronautical engineering
to try and get your hands dirty and design a real aircraft.
The request was indeed an air taxi service,
then design aircraft and air taxi service
located in New York in 2030;
asked to put the focus on the commuters,
therefore the target of this service had to be the commuters.
It automatically follows that the rates had to be very low,
so it had to be a non-élite service but just for everyone, almost everyone:
we talk about a tax rate similar to that of taxis,
as you know in America, unlike in Italy,
they are much more, let’s say, at popular, affordable prices.
Implicitly the announcement suggested using an unconventional propulsion,
so not the classic fossil fuels but something different,
be this electric, hydrogen, hybrid … something like that.
Naturally, the answer to the question we asked ourselves:
“it is possible – it will be possible – to move by air taxi” is yes,
otherwise we would not have taken part in the competition,
and our suggestion of how to do this
it is this aircraft you see behind me.
It’s called Flynk, crasis of Flying Link,
and the best proposal was judged, so we were nominated winners
and we went to present this aircraft at a congress in America.
Highlights in brief:
an all-electric four-engine
transport of 9 passengers:
this number is mainly linked to a regulatory constraint,
the bigger the plane, so the more people it brings,
the more stringent the regulations are.
This works with steps,
then exceeded the 9 passengers the regulations become extremely heavy,
so it is quite classic as a number for this category of aircraft.
Autonomy, studied ad hoc
for the New York metropolitan area, it is 35 miles,
plus the classic reserve required for aircraft,
that for this category is 20 minutes of flight,
and its main characteristic, as well as the main project constraint,
it’s the ability to take off and land on an extremely short track,
the announcement was 500 feet, or 150 meters, which is more familiar.
A few numbers for the engineers present:
MTOW (it is the maximum takeoff weight), so up to 2873 Kg we are able to take off.
How can you …
as someone more familiar with aeronautics, you will notice the wing area, 20 m²,
is significant for aircraft of this size,
but, as I said before and will often come back,
the reason is: we must be able to take off in a small space,
so at low speeds:
It is intuitive even for non-professionals in the sector that a large wing facilitates this discussion.
Innovative propulsion system:
I will speak mainly of this aspect because, let’s say, it is the most interesting for everyone
so we’re talking about an all-electric system,
therefore of batteries, of electric motors,
a specially designed propeller, with a series of constraints, and gondolas,
which are substantially that portion of the wing
which contains engine and structure we say of the propeller,
also a bit ‘special.
We said motors engines from the world of Formula:
FormulaE is a car competition similar to Formula1,
clearly electric cars.
These engines have performance today
that for our requests are sufficient, they lack reliability.
As you can well imagine the engines to be authorized on the fly
they must have a very high reliability,
you have to be almost certain that an engine will never be lost,
if not for absolutely particular and rare reasons,
for which we estimated that for 2030
it will be possible to have these same engines, with the same, more or less, characteristics,
and sufficient reliability to be authorized on the fly.
On the other side the batteries:
as you surely know at the moment there is a strong research on the batteries,
the electrical devices are spreading like wildfire: smartphone,
now also electric cars, like Tesla, entirely electric,
they are becoming more and more common, so there is very strong research in this field
and even there are institutions that study
just the predictions of how the batteries will go,
to allow designers, then us,
to design something that will happen in 2030
with the technologies that are estimated to exist in 2030:
in this case lithium-sulfur batteries, recharged with the fast charging technique.
What does fast charging mean?
It is a technique that is already used on Tesla cars:
it’s about recharging with a voltage higher than normal,
so much faster than regular top-ups,
and this, if you take the battery to full capacity,
it damages the battery very quickly.
This technique foresees to stop at 80% of the maximum capacity:
in this way the battery is not damaged
despite the various fast charging cycles.
Naturally this requires oversizing the batteries,
because this 80% must be enough for us to go all the way.
The propeller designed ad hoc, this propeller:
who understands it immediately realizes that for small airplanes
almost 6 blades are not used on such a propeller,
typically 2, maximum 3 blades are used;
they are instead used for larger sized aircraft
to reduce precisely how much thrust, substantially, is loaded on each blade.
However, we need to have a very low load on each blade
This because? Because the biggest constraint is that on noise
There was an air taxi service from JFK, New York airport,
it carried in the center of Manhattan, but this service was closed
not for attacks, problems related to security, but for a simple reason:
who worked in the surroundings of this heliport, which was placed on the top of a skyscraper,
he complained about the noise of these flights, which were quite rare.
We are planning an aircraft that must fly continuously,
several specimens that fly continuously over Manhattan,
we must be extremely silent to be accepted by society.
So low noise, excellent performance at very low speeds.
Once again the critical moment of our aircraft
I’m taking off and landing,
and in these phases we must have
maximum efficiency, we must be precisely as efficient as possible.
The positioning of the propellers in the ends is unconventional:
as you see the aircraft below, despite having 4 propellers,
do not place them in the ends.
We have made this choice why?
Because this allows us to simplify a lot
another expedient we used,
which is to rotate the external propellers.
Turning them around 30 degrees allows us to have a traction not only forward,
but also upward, then once again take off at lower speeds.
Very short takeoffs and landings, this is the main point:
we have an available track of only 500 feet, 150 meters,
and we have stringent acceleration constraints.
Let’s say that they exist, it would be possible to design propellers, to use engines
that give us accelerations higher than those provided by our aircraft
but this would generate uneasiness in people;
there are airplanes, the fighter departing from the aircraft carriers,
start at 3 G …
nobody wants to be shot at 3 G before going to the office.
Probably we have attested
on typical accelerations of conventional aeronautical aircraft,
the conventional airliners, therefore, approximately, a little less than half of the acceleration of gravity,
both accelerating, then taking off,
that braking, then landing.
In landing we also use push inversion,
then the propellers are rotated in the opposite direction to the conventional one,
or rather they always rotate in the same direction but with a different angle.
This allows braking the aircraft,
another reason why the propeller was preferred to other types of engines.
This is the air taxi service of the future that we think;
naturally, an app has been designed within the service,
so all that boundary set that makes it extremely easy
take advantage of this service,
both the positioning of the stations, which you see in the map on your right.
The stations are on the water, maybe they are a bit small, I do not know if they can be seen.
Manhattan is served precisely with slopes on the water,
because the positioning of these tracks, even if short,
it can not happen in a hypothetical Central Park
nor on the roof of buildings, but just on the coasts.
This still allows serving an excellent portion of Manhattan,
just think that one million four hundred thousand commuters arrive every day in Manhattan
more, on average, half a million visitors,
obviously with peaks in the tourist seasons.
We are not going to serve these, basically, two million people,
we’re going to serve a smaller portion,
but we will still lighten existing transport,
one of the bases of the tender was:
“Manhattan is an extremely interesting destination
for these two million people, but has geographical constraints:
being a sort of peninsula a large part of the population reaches it through,
almost all of it reaches it through bridges, tunnels
or taking the ferry, so it’s hard to get to.
We, with our service, would go to relieve
existing infrastructures, which can hardly be upgraded,
of a significant portion.
Thanks for your attention, that’s all,
if you want to contact us for further questions, maybe something more technical,
we are more than available.
Thank you all.
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