Surely he can’t be serious. Yes, he can – and don’t call him Shirley.

“Airplane!” is, without question, the absolute pinnacle of parody movies. Often imitated, sometimes almost equalled but never, ever bettered. It’s so densely packed with gags that even now, forty years after it was first released you can always spot a new one you’ve missed on previous viewings, regardless of how many there have been. A spoof of the po-faced melodrama of the disaster movies of the 1970’s – particularly the “Airport” series which didn’t survive this devastating satirical blow – its actually based on an almost forgotten 1957 movie “Zero Hour!” (in case you wondered where the exclamation point in “Airplane!” came from. “Zero Hour!” was written by Arthur Hailey who would later rework his teleplay into the novel “Airport”, so it was only natural Zucker, Abrahams and Zucker would go directly to the source to deliver their masterpiece.

When troubled war veteran-turned-cab driver Ted Striker (Robert Hays) boards a flight at the last minute to try to win back his stewardess girlfriend Elaine (Julie Hagerty), neither of them are prepared for what follows. When the passengers and crew fall ill due to food poisoning, Ted is the only one who has a chance to fly and land the plane safely – if he can control his drinking problem and get over Macho Grande.

Around this archly melodramatic plot, Zucker, Abrahams and Zucker skillfully layer after layer after layer of humour. There are the usual tropes of disaster movies cranked up to the point of absurdity as we follow various passengers and families through their own ordeals while our heroes tackle the existential crisis facing the entire plane. There’s scattergun social and pop culture commentary in there, echoing their earlier efforts like “The Kentucky Fried Movie” and some wonderful recurring character stuff too. Among those joining in the fun and sending up their real-life personas are Peter Graves, Kareem Abdul-Jabbar, Robert Stack and Lloyd Bridges (who deserves as many plaudits as Nielsen) while Julie Hagerty and Robert Hays anchor the comedy and silliness with genuine romantic chemistry and a knowing wink to the audience that they’re in on the fun. It takes swipes at other famous movies too, notably “Jaws” and “From Here To Eternity” but it maintains that essential discipline never to do so at the expense of its main target.

While the likes of Graves and Bridges indulge in deliberately silly subversions of their usual roles, the genius of Nielsen’s performance is that he – almost without exception – plays the role of Doctor Rumack entirely straight, regardless of what’s going on around him. It’s a performance that’s so effortless that it’s easy to underestimate the skill required to make it work. Every single line, action and expression is delivered with laser-accuracy comic timing and in a movie packed to the rafters with memorable gags and moments, it’s no coincidence that Nielsen’s lines are among the most iconic. While not the lead, he’s the character through which all the others are able to move through the plot and deliver the movie and in every moment you can feel the relish with which Nielsen is sending up so many of his previous roles.

It could have all been so very different, too. Following a successful appearance hosting “Saturday Night Live”, Christopher Lee was cast in Spielberg’s WWII comedy misfire “1941” and so had to turn down the role of Doctor Rumack, something he acknowledged later to be a big mistake. Dom DeLuise and Jack Webb also turned down the role before the gods of comedy decided enough was enough and gave Nielsen his shot at comedy immortality.

A huge success upon release, “Airplane!” created a whole new genre of cinema and anointed Nielsen as its king, a reputation he would retain despite the variable quality of his output in the years which followed. Of course, he’d hit the big time once again with Zucker, Abrahams and Zucker (and Pat Proft) with the Naked Gun Series but “Airplane!”, despite being steeped in the pop culture of the late seventies and early eighties, retains a somewhat timeless quality even by today’s more puritanical social standards and forever marks the point where parody movies took to the skies and soared higher than ever before.