Directed and co-produced by Clint Eastwood, the film Sully claims to tell the true story of the “miracle on the Hudson”. Instead, it is another rightwing attempt to delegitimize government – and in the process undermine the safety of millions who travel by air, train, road and boat.

The miracle happened in January 2009 when US Airways flight 1549 smashed into a flock of geese, just three minutes from New York City’s LaGuardia airport. With both engines out, pilot Chesley “Sully” Sullenberger, aided by co-pilot Jeffrey Skiles, made the gutsy decision to forgo trying to get to an airport runway. Instead, Sullenberger dead-sticked his Airbus 320 to a landing in the Hudson river, saving the lives of 155 people. The flight lasted six minutes.

Sully depicts this feat of gifted airmanship with all the vérité that Hollywood’s cinematographic wizardry can bring to bear. It also, generously and wisely, includes others who played vital roles, such as the unflappable flight attendants and the ferry boat crews that plucked passengers from the deadly cold.

However, Sully is mostly concerned with the subsequent investigation, and it’s here where it diverges from reality.

Sully is, in theory, based on Sullenberger’s 2009 memoir Highest Duty (co-authored with Jeffrey Zaslow). “Until I read the script, I didn’t know the investigative board was trying to paint the picture that he had done the wrong thing. They were kind of railroading him,” says Eastwood in one promotional trailer. It’s not surprising Eastwood was ignorant of any railroading by the National Transportation Safety Board (NTSB), since it’s a narrative absent from Highest Duty, or anything actually said or written by the NTSB.

In fact, in his memoir, Sullenberger reflects that he was “buoyed by the fact that investigators determined that Jeff and I made appropriate choices at every step”. When he and Skiles were invited to the cockpit voice recorder playback, Sullenberger notes the investigators were eager for the opportunity to hear the pilots’ thoughts. As he describes, the playback happened four months after the flight in a room with six people. Yet in Sully the playback occurs days after the flight before a packed kangaroo court. The exhausted pilots are hounded by ankle-biting bureaucrats, and presented with incriminating simulations that show test pilots easily making runway landings.

Ultimately, the investigators are embarrassed into decency. Sullenberger achieves victory by demanding – essentially from the dock – that the simulations include the time needed for adequate situational assessment.

In reality, investigators first asked simulator pilots to attempt airport landings immediately after engine loss to establish the bounds of practicality. Notably, even with the benefit of perfect hindsight, barely half of these optimal test runs made it back. And then the investigators – not Sullenberger – asked a pilot to wait 35 seconds before attempting an airport return. That flight didn’t make it. Consequently, the NTSB was unequivocal in its declaration that the Hudson was the right call.

But does Sully’s portrayal of NTSB investigators as bullying incompetents matter? After all, whenever a movie based on true events is released, there are always cries of “it didn’t happen that way!” This occurs because of the inevitable changes required when dramatizing real-life events. These include creating composite characters, eliding side issues and compressing chronologies.

In evaluating such storytelling decisions, what’s important is whether or not the top-line takeaway is fair. For example, despite considerable fictionalization in The Imitation Game, viewers come away with the correct impression that Alan Turing was a computing pioneer, who was persecuted for his homosexuality and made major cryptographic contributions to defeating the Nazis.

With Sully, the film-makers were faced with a problem: how to make a feature-length movie about a six-minute flight? They took the easy way out and invented an antagonist. As a result, the takeaway is that the NTSB – as I heard one person leaving a screening say – “tried to stitch Sully up”.

It’s not hard to see why this tack appealed to strident libertarian Eastwood. In its populist zeal, the American right wing has been increasingly unwilling to accept the legitimacy of any branch of federal government. Sully meshes perfectly with a worldview where petty and clueless civil servants obstruct real Americans from being great.

Most people – including elected officials – are not familiar with how NTSB investigations work. As a box-office hit, Sully will form the first, lasting, impression for many. This has real risks.

Around the world, the NTSB’s investigations are regarded as setting the gold standard for impartiality, perceptiveness and making recommendations with important safety benefits. The NTSB has saved countless lives. Yet the NTSB has no regulatory ability: to turn its recommendations into practice, the board relies solely on a moral authority founded on its reputation for diligence. The stakes are high – the board currently has a list of 10 critical safety improvements that it’s trying to get implemented, including, for example, positive train control, something that would have spared 243 people last year from a deadly Amtrak derailment.

Sully has smeared this reputation for the sake of a hero who needed no defending. It will create a headwind in the minds of the public and policymakers that the NTSB will be struggling against for years to come.