The FBI interviewed Roberts at the time, and got him to reveal exactly what sort of stuff he was getting up to. He admitted to as many as 20 attacks, including one that really concerned the intelligence agency.

FBI documents made their way to Canadian news organisation APTN, which reports on the affidavit and other information.

"[Roberts] stated that he successfully commanded the system he had accessed to issue the 'CLB' or climb command. He stated that he thereby caused one of the airplane engines to climb resulting in a lateral or sideways movement of the plane during one of these flights," said the affidavit signed by FBI agent Mike Hurley.