Luther, The Wire and Suicide Squad star Idris Elba says the accomplished business negotiator he plays in the new high-altitude thriller, Hijack, is unlike many of the "big lad" tough guys he has played in the past.

"Even though Sam is what he is, he isn't always the sort of hero," Elba added. "It's more cerebral. He's quite vulnerable in the sense that he's got lots going on internally in terms of his family."

Premiering Wednesday on Apple TV+, the show unfolds in real time -- one hour per episode -- and follows those onboard a hijacked flight from London to Beijing.

Elba plays Sam Nelson, who uses his unique set of skills to try to save the lives of the passengers and crew.

The filmmakers said there are myriad challenges in creating a show like Hijack.

"We spent most of our time making Idris look presentable," Smith joked.

"There are two problems," Smith said. "One is to make it engaging dramatically and not feel dull and flat and the other thing is to make it feel like you are actually in an airplane moving through the sky."

The aircraft depicted on the show is a "millimeter for millimeter" replica of a real airliner, according to the director.

"We didn't really want to break this plane apart. We wanted to move around the plane and never break through the skin of it," Smith said.

"I didn't want the thing you sometimes see on screen where everything gets scaled up to make it easier [to film]," he added. "We made it as hard for ourselves as we possibly could in hopes that translates onto the screen into something that feels really convincing."

Smith said there were as many people as viewers see on screen "plus whoever was behind the cameras" on the mock plane.

This understandably wore on the actors after a while.

"It felt like I was flying to Mars," Elba said. "I was just like: 'Am I still on this flight? Six months later, I'm still on the flight, or three seasons of the show, are we still here? What's going on?'"

Elba also quipped that he sought the extra leg room in the first class section of the plane whenever possible.

"This is a real plane, just in the studio, and the confinement of that just really applied to the drama," he said.

"It all led into the claustrophobia of it, so the crew, the actors, were sort of tight. It was almost like watching a documentary being made while you were in the documentary."

Fight sequences weren't easy to execute because they took place in such tiny spaces with little headroom.

"If we hurt ourselves, we just took a breather and carried on," Elba said.

"Not to say that we didn't care, but it's just we didn't try and change the choreography not to hurt ourselves because, in this instance, the fight sequences were based on, 'What would we do?' rather than,'This is a fight sequence.'"

Sam also is not a fighter by nature and Elba wanted his performance to reflect that.

"He's fighting out of desperation and he's frightened of getting shot. Not only is he frightened of getting shot, but he doesn't want the plane to go down because of a bullet," Elba said.

Smith said he used a lot of unbroken film shots, which also contributed to the tension and authenticity of the story.

"We often moved with Idris' character Sam," he added. "It was all about wanting to feel engaged in the drama of it and not feel like it was artifice. We want you to feel like you are in that hijacking."

The idea for the series came to Kay when the Eurostar train he was traveling on in France stopped abruptly in a tunnel, prompting him to imagine horrible scenarios about what might be going on in the other cars of the locomotive.

"I looked around me at the people -- the businessman eating his lunch, the family -- and I thought: 'How would we come together if this was a serious incident? Would the tough-looking guy really be tough? Would the weedy guy rise up and cover himself in glory and stand up for people? Who are these people?'" Kay recalled.

He then transferred those musings to a plane.

"It's high stakes and also a moving society," Kay said.

"There's a class system on a plane and all sorts of people," he added. "The hijacking is a great leveler for all of these people. They really get tested, no matter what their rank or class of seat they are sitting in on the plane."

Cast members whose characters were on the imperiled flight didn't mix much with those actors who portrayed government officials and family members frantically trying to help from the ground.

"We're shooting at a studio with several stages, and because I couldn't sort of go and see what the other stages were doing every now and then, I'd always stay near the back, and then one time I realized I was walking right through, basically, a whole shot," Elba recalled.

"Archie was in there, I think, and everyone was huddled in this tiny room, and they were just running lines, right? And I just walk past," he added. "And I was like, 'Hey!' and they all looked at me like, 'What are you thinking?' I was in full costume, blood on my face."

Elba thought his co-stars would be happy to see him on this rare occasion that their paths crossed.

"They were like: 'What are you doing here? Just get out, man. You're killing our vibe,'" he said.