GEORGE CLOONEY, in his 2009 film Up In The Air, plays frequent flyer ad extremum, Ryan, whose job is to fly around America firing people.

“Never get behind old people,” he says on airport security. “Their bodies are littered with hidden metal and they never seem to appreciate how little time they have left.” This is the advice of a seasoned traveller.

We all have an opinion on airport security. You know you’re not a terrorist, but they don’t, and that’s an innocence that has to be proved.

Nonetheless, they’re either the traffic wardens of the sky or the guardians of your journey. The deciding factor tends to be our mood, but most sensible people subscribe to the latter.

It’s not always the case, though, and it’s in those moments when administering airport security becomes an unenviable task.

Marshalling the front line of this zone between check-in and boarding at is Airport Security Manager Sundeep Balley, 24, from Greenford, Heathrow’s youngest-ever security officer.

Each eight-hour shift involves 20,000 people going through security.

Such is the responsibility of this job that he is about to star in ITV’s mini-series documentary, Britain’s Busiest Airport.

The show will be following staff at Heathrow – in security and elsewhere – as they process masses of travellers.

“You get the difficult incident here and there,” said Sundeep, playing down the inevitable stresses that come with the job.

“With everything going on around the world, people appreciate what you are trying to do, especially those with kids.”

It’s this kind of calm and reasonable approach that makes Sundeep’s rise through the ranks little surprise.

His position today was seven years in the making.

Having always taken an interest in his father’s job at the airport, he began work at 17, starting an 18-month Heathrow Duke of Edinburgh scheme, culminating in an award ceremony at St James’ Palace.

Security officers are trained to deal with stressed travellers, and Sundeep understands that people may not have had good journeys up to that point.

He remains typically unaffected by the demands of the job and the eternal need for people skills and diplomacy.

I pressed him to lift the lid on daily tensions and past outbursts, but he assured me it’s all part of the job. “Most people are quite friendly,” he says.

Of course, it may be that Sundeep’s standards are higher than the average person’s and what most would consider difficult simply does not faze him. That theory is bound to be put the test this Thursday evening.

If the unflappable Sundeep’s assertions are anything to go by, then airport security is not as daunting as one might imagine it to be, but our verdict on this week’s show will surely be the acid test of his claims.

Britain’s Busiest Airport Episode 3, Thursday, June 18, ITV, 9-10pm.