American Flight 965, a Boeing 757 descending at night toward its destination at Cali, Colombia, collided with an Andean mountain ridge, killing 159 crew and passengers. Miraculously, four passengers did not die.

The accident report that emerged from the investigation laid all blame at the feet of the pilots, softening the blow by citing some flight management system navigational anomalies as contributory factors.

Recently an independent re-examination of the data by a team of aviation and accident investigation experts has concluded that simply writing off the crash as “pilot error” was a bad decision. The pilots were among American’s best, yet the crew exchanges on the cockpit voice recorder, according to their peers, demonstrated a degree of confusion that was out of character.

Initially the Colombian/American investigation team believed alcohol in the pilots’ blood might have been a factor, but later forensic testing confirmed the alcohol was a product of tissue degeneration. Having ruled out alcohol as a cause of the pilots’ uncharacteristic confusion, the investigators failed to ask whether there might have been an alternative explanation for it, confining the event to history as simple pilot error.

A new feature-length documentary film about the American Airlines Flight 965 opens in the USA this week, examining the official accident report produced at the time by the Colombian authorities with the aid of the US National Transportation Safety Board. It raises questions that should have been asked at the time, but were not.

If this new investigation reveals the truth for the first time, it will shake public confidence in the commercial air transport industry.