Idris Elba may seem an unflappable kind of guy, but he’s revealed how his new series sent him into a spin.

In Discovery’s Idris Elba: No Limits, the Luther star takes on a number of challenges such as rally car racing, aerobatics and drag racing but it was the aerobatic challenge that was the hardest task because he has a fear of heights!

So, before he could even take to the air, he had to conquer his acrophobia…

Idris Elba in Idris Elba: No LimitsIdris Elba got scared about the aerobatics (Discovery Communications)

“The biggest struggle for me is dealing with my fear of heights. Comfort zone-wise, this is pushing my fear factor to the limit,” the actor said.

Idris, who will reprise his role as maverick detective John Luther in the BBC crime drama for a TV special later this year, enjoyed the driving challenges.

Idris Elba took part in the Circuit of Ireland rallyIdris Elba took part in the Circuit of Ireland Rally (Charles McQuillan/PA)

“Driving is what I like to do – it’s on the ground! Rally driving was always on the TV back in the day when I was kid,” he recalled.

“My dad worked at Ford and he used to bring home old steering wheels and I used to have them on my lap pretending to be a rally driver.”

Idris also enjoyed drag racing, saying: “I’d never felt anything like that in my life. I thought we were going towards the sky, it was that intense!

“And then it was eight seconds of just the most intense power – I’ve never had power that intense in my life. It’s incredible. I was genuinely scared.”

Idris Elba: No Limits airs exclusively on Discovery Channel on 6 July 6 at 9.00pm.