Nicholas Barber on Flight: Denzel Washington gets the shakes on a plane

Robert Zemeckis loses control of his plot in Flight (138 mins, 15) and FDR seeks excitement with his stamp collection

One thing's for sure: Flight is never going to be shown as an in-flight movie. In the first half-hour, there's a fantastic, white-knuckle sequence in which a commercial airliner's engine falls to pieces. As the altimeter-needle spins and the passengers scream, even the most blasé of frequent fliers will be making a mental note to pack the Valium the next time they're due to catch a plane.

It could have been worse, though. Thanks to the cool-headed brilliance of a quick-thinking captain, "Whip" Whitaker (Denzel Washington, deservedly Oscar-nominated), the aircraft crash-lands in a field, and almost everyone survives. Whitaker is a hero – sort-of. The twist is that he's also an alcoholic who was up to his eyeballs in vodka and cocaine when he saved the day. It's a bold, even subversive premise that keeps raising more and more questions. Should the airline blame Whitaker for the crash, even though they know it wasn't his fault? Should the pilots' union pay a hotshot lawyer (Don Cheadle) to get him off the hook, even though they know he's a liability? Should Whitaker's colleagues cover up his drinking to keep him out of jail? And, considering that a wing clipped a church's steeple on the way down, was the crash an act of God in more ways than one?

Like a more mature cousin of Jason Reitman's probing satires, Thank You for Smoking and Up in the Air, Flight poses these questions with crackling cleverness and devilish confidence: you never doubt that the film-makers know what they're talking about. Unfortunately, that's not the whole story. For every one of its smart, surprising scenes, there's another conventional and sentimental one, set on Whitaker's family farm in Georgia. It's there that he muses on his past and ponders his future, often in the company of Kelly Reilly's tart-with-a-heart, who comes to live with him minutes after they meet in hospital. As committed as Reilly is, not even she can make us believe in a hopeless heroin addict who transforms, instantly, into a happy, healthy ministering angel. In effect, Robert Zemeckis and his screenwriter, John Gatins (also Oscar-nominated), are giving us two films for the price of one, but one of them is an audacious masterpiece while the other is a soft and snuggly daytime TV movie. In the final, disappointing scenes, the inferior film pulls the superior one away from the controls, and Flight cruises to its destination on autopilot.

Officially, Hyde Park on Hudson (Roger Michell, 95 mins, 12A)may not be a sequel to The King's Speech, but unofficially there's no two ways about it. It's impossible to watch King George VI (Samuel West) and Queen Elizabeth (Olivia Colman) have their "I-never-wanted-this-life" conversation without remembering the last time they had it two years ago. And, like most sequels, this one obeys the law of diminishing returns. It's set in 1939, when the King and Queen visit Franklin D Roosevelt (Bill Murray) at his mother's country mansion. Also present is FDR's mousy mistress, Daisy (Laura Linney) and Eleanor Roosevelt (Olivia Williams), who doesn't care how, ahem, "refreshed" her husband appears to be after he and Daisy return from one of their long drives. Weirdly, Richard Nelson, the screenwriter, chooses to make Daisy his central character, never mind that her main function in proceedings is to cater to FDR's every whim while getting nothing in return. She's also the narrator, her cooing voice-over spread like syrup over half of the film. "Looking back," she says at one point, "I now see how important that day was."

Well, I'm glad someone does, because, Daisy's voice-over aside, Hyde Park on Hudson might have been designed to make the royal visit seem utterly trivial. In theory, the King is in the US to beg for the president's support in the imminent war, but in Roger Michell's glossily picturesque comedy of manners all political intrigue has been replaced by cocktail chit-chat. Murray – whose physical resemblance to FDR is uncanny in its non-existence – plays the president as a jovial old toper who would be more at home in Blandings Castle than the White House. He dispenses fatherly advice to the King, but he devotes less thought to the world beyond the Roosevelt estate than he does to his stamp collection. And, to be fair, after you've sat through a film in which the key dramatic question is whether George VI will consent to eat a hot dog at a picnic, stamp collecting does start to seem like a relatively rip-roaring pastime.

Shortly before the beefy Matthias Schoenaerts co-starred with Marion Cotillard in Rust and Bone, he appeared in Bullhead (Michaël R Roskam, 124 mins, 15), a brooding rural crime saga from Belgium, playing a cattle farmer who deals in illegal growth hormones. The film was shortlisted for a Best Foreign Language Film Oscar last year, but there's a reason why it hasn't been released in Britain until now. Although strikingly shot, the plotting is so confusing that I never got to grips with which character was selling hormones to who, or who murdered the policeman who was on to their racket.

Still, writer-director Michaël R Roskam has a powerful sense of mood and place, and Schoenaerts is on his way to international stardom. You can't look away from him. He's vulnerable yet dangerously volatile: a little-boy-lost with the body of the Incredible Hulk and a face that looks like it was hacked from a tree stump.