National Crime Agency investigators working with the FBI identified that, while on pre-charge bail for the threats to schools, Duke-Cohan made bomb threats to the US-bound flight via phone calls to San Francisco Airport and their bureau police.
In a recording of one of the phone calls, which was made while the plane was in the air, he took on the persona of a worried father, claiming his daughter contacted him from the flight to say it had been hijacked by gunmen, one of whom had a bomb.
Following the conviction, Marc Horsfall, the NCA’s senior investigating officer, said: “George Duke-Cohan made a series of bomb threats that caused serious worry and inconvenience to thousands of people, not least an international airline.
“He carried out these threats hidden behind a computer screen for his own enjoyment, with no consideration for the effect he was having on others.
“Despite being arrested and having conditions imposed restricting his use of technology, he persistently broke those conditions to continue his wave of violent threats.
“Law enforcement take such offences extremely seriously. The sentence handed down to Duke-Cohan today highlights the consequences of such offending.”