The future of flight shouldn't be things with propellers and turbines and should
be more like what you see in Star Trek; with a kind of blue glow and something
that silently glides through the air.
When I got an appointment at University
I thought well, now I've got the opportunity to explore this
and started looking for physics that enabled that to happen.
The sort of mechanism that I found that works was ionising air
and then using electric fields to accelerate the air.
What we achieved, was the first ever sustained flight of an aeroplane
that is propelled by electroaerodynamic propulsion.
And that's also by many definitions the first ever solid-state flight,
meaning no moving parts.
Well the idea is - is kind of - it dates back until at least the 1920s.
Where an eccentric inventor at the time started experimenting with high high voltage electrodes.
And thought he had discovered anti-gravity, which of course was not the case.
But that set some of the initial groundwork on mechanisms for creating
what's called an ionic wind in the atmosphere, by having high-voltage
electrodes ionising air and then accelerating the ionised air.
So what we did for this design is to
try and stick to something that looks somewhat like a conventional aircraft.
But under the wing rather than conventional engines
it has a series of electrodes. And those consist of an array of very thin wires at the front,
and then an array of aerofoils at the back.
Now those thin wires at the front are set at a very high voltage - plus 20,000 volts
and that constitutes the source of ions - this is ionised nitrogen from the atmosphere.
Now the the aerofoils at the back there set at minus 20,000 volts
and so that creates an electric field.
So the ions go from the positive to the negative
colliding all the way with neutral air molecules
and creating this wind that goes behind the plane.
And that's essentially how it flies.
The flight was about sixty meters long, something like ten seconds - so quite short.
It was constrained by the size of the gym that we found to fly it in.
Lacking infinite money in time and just wanting to do things as quickly as possible
that was what was on hand
and so we just asked the facilities manager if they would let us use the gym,
they forced us to create a very long and detailed safety management plan
but then we were able to go ahead.
Many attempts failed because of various things going wrong
like structural failures, the power electronics frying itself
so there are many many first days, but the first day that it actually worked
wasn't a sustained flight it was about 50% power, so it was a power glide.
Until that occurred we still didn't know 100% whether this was really achievable.
But after that point we knew that
we were then within touching distance of successful flights.
And the first sustained flights followed quite soon after, which were...
which were pretty exciting.
It's probably the first solid-state flight of a heavier-than-air vehicle
and I think that is, has the potential to be a step that is very interesting.
Of course we don't yet know whether it will be
practically useful and widely used and obviously I hope it will be
and have an expectation - there are a number of applications.
There are definitely some limits,
so one of the limits is the breakdown voltage of air
and that varies as a function of altitude.
And we've worked out theoretically what the
limits are to the thrust density which is the amount of
thrust force per unit area that's producible.
Now what that suggests is that in the nearer term,
it will be easier to create smaller vehicles like drones for example.
I think the near-term advantage is probably in noise
especially if you think that
perhaps in ten years we might have urban areas that are filled with drones doing
things like monitoring traffic, monitoring air pollution
or many other services we're yet to imagine.
And drones today are quite noisy and irritating.
Now we wouldn't want our urban environments to be polluted by all this noise,
so developing a way of propelling drones that's silent or near silent would be
advantageous in that context.
In many ways it's much easier to make progress now than it was in the past.
I mean if you look at this wonderful aircraft behind us
which was the first ever transatlantic flight - about 1919
I mean people were risking their lives to make that kind of progress.
Today we're not risking our lives
we're able to test things using a remote control,
without having to have pilots on board test vehicles.
That means the vehicles can be much smaller
which enables us to build them and test them with less resources.
In terms of how this fits in
I don't know whether you'll see large aircraft carrying people anytime soon.
But obviously I'd be very excited if that was the case.