"Hi, we attach pyrotechnics to our planes

"so we can produce a fireworks show in mid-flight.

"Do you want to come for a test ride?"

[radio] "Going right, now."

What else was I going to say?

Look at that sunset.

Oh, wow.

- My inspiration for Aerosparx came from seeing New Years Eve on television,

in Edinburgh, where underneath the castle they had a waterfall of light.

I always imagined that being somehow trailing off behind the wing of an aeroplane.

- Aerosparx, as a display team, we are lucky enough and privileged enough

to go all over the world.

We've been to China, Saudi Arabia, Portugal,

lots of locations in Europe, and obviously locations in the UK.

And we can display from up to 300,000 people, to a million people.

- All right.

It is nearly dark enough and our planes are nearly in position.

This is going to happen very soon.

Just to be clear, this is a practice run.

This is not a proper display.

When it's a display, there is a lot more going on in the cockpit,

a lot more going on the pyrotechnics,

and they are very much not allowed to take passengers.

But, um, yeah. Let's see what this is like.

- And, relax(!)

- Are my nerves that obvious?

- One of the big wows is flying in extremely close formation.

We're helped by the wings being extremely long,

so your peripheral vision is just full of aeroplane.

- I don't see Guy very often,

but I know that he's probably only three metres from my aircraft,

and that's where trust comes in.

- You'll see us firing lots of different kinds of fireworks, pyro, from the aeroplanes.

They all need preparation and that can take some hours.

So all of the igniters, eMatches, need inserting into the fireworks.

We need to work out what we're going to put on the aeroplane where,

and then the process of actually fitting the aeroplane, again,

can take half an hour to an hour.

We genuinely can't shimmy down the wing and light the blue to uch paper.

All commercial firework displays are ignited the same way.

They're all ignited with a control box lighting an eMatch or an igniter.

And that goes into the blue touch paper, effectively.

And we do just the same.

We started out by having a bank of switches.

But when you're under high workload in formation flying,

it's so easy to hit the wrong button.

We can fire 24 separate fireworks in our display.

You can't get 24 right in a sequence.

So we've actually had a bespoke computer system designed,

and not only does it fire our fireworks for us, but it also

controls the LED light system on the aeroplanes as well.

And that means I now have only one button.

So once I've pressed it once, it then auto-sequences onto the next part of the programmes.

My imagination, I've found over the years,

has always been a leapfrog ahead of the authorities' regulation.

Not trying to stop what we're doing, but trying to understand what we're doing,

and finding out where it fits into regulations that were written, quite genuinely,

not for aeroplanes.

So at the moment we're dealing with aviation regulation and firework regulation.

[radio] Diving now.

Loop now.

Fire, fire, fire.

Loop. Loop, now.

- Check your CB, Rob, check your CB.

- So the question is, how can they do this?

And how can they do this safely?

[radio] Loop.

Loop, now.

- We have defined roles.

My job is to lead the formation, lead the display.

- Rob is working very hard in the climb out,

working out exactly where to start the display,

and how to modify the display subtly

to keep it in the right place with the wind conditions.

My job is very clear,

to fly safely and as close as I can without hitting him.

Planning is everything in our display,

and that planning starts on the ground before we even get airborne.

We do a bumblebee dance, as we call it, so we go around in circles,

in our mind and physically mimicking the manoeuvres that we're then going to do in the sky.

And that then sets a cadence and a rhythm, and the physical memory of what you're doing,

so that when we start a display, we're on the same page and working as a team.

On the radio, we're confirming all the time what we're going to do before we do it.

- Okay. Firing now.

- Our choice of using a Grob 109 motorglider was for lots of reasons.

One of my original imaginations of this firework display

was to separate the fireworks as far as we could, and we needed a big wingspan for that.

Because it's a glider, it also has the efficiency of a glider.

Which means that we can perform aerobatics with a very small engine, and it gives us grace.

The disadvantage with a motorglider is a very small engine.

That means we take a long time to climb to altitude,

and when we're at altitude,

we try and conserve all the energy we have.

We describe our as play as painting with light.

We like to think that the focus is more on the image we're painting with the aeroplanes,

rather than the distinct manoeuvres we're doing separately.

Fireworks are great on the ground,

when you're flying next to fireworks, it's even better.

And I still pinch myself every time I even think about going flying with fireworks,

and just think, 'I can't believe we're actually going to do this'.

- That's incredible.

So that's, what, two tests now. And what are you doing tomorrow?

- Tomorrow will be twice as much pyro in the same length of time.

So it's going to be Armageddon.

- Thank you so, so, much.

- Very good.

- You can find out more about Aerosparx and all the displays they're going to,

at the link in the description.

- Thank you.

What we are going to do is turn the engine off.

- Oh. - And land as a glider.

- Okay. Um.

Sure!

- There you are, look. No engine.

The propeller's just... just stopped.