Isn’t that the most brilliant thing? Beautiful too. The Jetmen of Dubai, a couple of fearless Frenchmen who strap delta-wing jetpacks to their backs, turning themselves into miniature planes, then fly in formation over the Arabian desert. It’s about as near as you can get to being Peter Pan. How do they land, I wonder? [Checks the internet – oh, like that.] Once you’ve found the Jetmen on the internet, it’s hard to get away, and you’ll soon find you’ve lost half an hour. Love the stunt with the big Airbus A380.

This is City in the Sky (BBC2, Sunday), and it’s not just about French daredevils, it’s about all things aviation. In this second episode we’ve taken off, we are up there, and Dallas Campbell and Hannah Fry are looking at how the hell we stay up there. Yves and Vince, human fuselages with their strap-on wings, are here to demonstrate lift. (And to be cool. “You can play with clouds,” says Yves, romantically). But there’s more to it than just physics; there are other important questions for science broadcaster Dallas and mathematician Hannah to look into.

Such as: how does the pilot know which way to go? How do we avoid bumping into the other million or so people up there at any one time? What happens if the plane gets struck by lightning? Or if you’re struck down by a stroke? Why do stallions go at the front, and mares at the back, if it’s a flight for horses, not people? And do they – the horses – get jet lag?

The answers, respectively? The pilots follow waypoints, digital breadcrumbs in the sky (“More or less yes, like Hansel and Gretel,” says the nice Luftansa pilot, flying his A380 from Frankfurt to Delhi). And they follow invisible highways, with loads of rules about how far they have to stay away from each other, rules that can presumably be waived for delta-winged Frenchmen.

The lightning strike? Pretty common, as it happens and not too serious, thanks to something called the Faraday Effect, which I vaguely remember from school. It gets a bit more complicated in a new carbon composite plane, which has to have copper mesh woven into it to disperse the charge. But basically you’re OK.

A stroke, or any other serious medical problem you might have during the flight? Dr Doug Ross will see you now. Not the real Dr Ross (who is fictional anyway), but an ER doc who does look a bit like George Clooney and who works from a room in a hospital in Phoenix, Arizona, advising cabin crews all over the world as they deal with passengers in trouble. (“Is he breathing on his own, over?”). Kind of ER by proxy, then. So in fact, Dr Ross never actually sees any of his patients – or even finds out if they make it. What’s the point in having a handsome doc if you never get to see him?

And now to the really interesting part, the horses. Dallas is following a Belgian stallion called Chardonnay – is that fair, calling a male horse Chardonnay? – who is flying with 63 other thoroughbreds from Liege to Hong Kong for a showjumping event. And Chardonnay and the other stallions go at the front. “You don’t want stallions behind mares” explains the vet. “If the mare is thinking about coming in season, stallions are designed to react to that, and they will react to that.” Yes, I can see that a 64-horse orgy could make for a bumpy ride – almost as bad, I imagine, as having Kate Moss, Gérard Depardieu, Naomi Campbell and the England Supporters Club all in the back of your plane.

And does Chardonnay get jet lag? Yes, though he’s not very good at talking about it, so it’s hard to know how it compares. If Chardonnay was flying in a carbon composite plane like a Boeing Dreamliner he would be less likely to suffer because they can withstand higher internal pressure meaning more oxygen for the passengers, human or equine.

See, it’s interesting. And you thought you knew pretty much everything there was to know about the business of going from A to B in an aeroplane. Who would have thought there could be a fascinating, fresh, three-part documentary in it? But Dallas and Hannah have dug one out, clocking up a fair few airmiles, and text messages to each other, in the process. They’re good, just the right mix of fan and geek, wow and this-is-how. But the stars of this one are two crazy, winged Frenchmen blasting across the Dubai sky.