George Duke-Cohan twice targeted schools in the United Kingdom and USA with hoax messages, before phoning in a fake report of a hijacked aircraft while under investigation. He was sentenced to one year in jail for the school emails and two years for the airport security scare in which the aircraft - with 295 passengers on board - had to be quarantined at San Francisco airport.
Avonbourne Trust has four academies; Avonwood Primary, Avonbourne College, Harewood College and Avonbourne Sixth Form.
George Duke-Cohan, 19, from Watford, Hertfordshire, sent emails to more than 400 United Kingdom schools warning about an explosive, according to the National Crime Agency.
"You were playing a cat-and-mouse game with the authorities".
'You were playing a game for your own perverted sense of fun in full knowledge of the consequences'.
Sitting at Luton Crown Court to sentence Duke-Cohan, the judge told the teenager this morning: "You enrolled to study for a Diploma in Information Technology at West Herts College in Watford in September 2016".
Duke-Cohan's bomb threat against United Airlines included him making a phone-call to San Francisco authorities in which he took on "the persona of a anxious father and [claimed] his daughter contacted him from the flight to say it had been hijacked by gunmen, one of whom had a bomb", said the National Crime Agency in a previous statement.
One particular email said: "This is a message to everyone".
A teenager has been jailed for three years for making hoax bomb threats to hundreds of schools and a transatlantic flight. If you do not send the money, we will blow up the device.
Officers recovered multiple electronic devices belonging to him, the use of which was in contravention to his bail conditions imposed on him. Duke-Cohan and other Apophis Squad members also attacked the free email service Protonmail, even as all of them continued to use their Protonmail accounts to communicate about the attacks.
Such conditions did not deter the teenager, as he was then linked to a third hoax, regarding a fake tip-off that hijackers had taken over a United Airlines flight between the UK and San Francisco in the USA in August.
NCA investigators working with the FBI identified that whilst on 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.
Duke-Cohan was arrested for a third time on 31 August.
The judge said for the purposes of sentencing he accepted Duke-Cohan has autism spectrum disorder.
The calls were taken seriously.
Judge Foster said: "I of course accept that the age of 18 is not a magical cliff-edge when young people become mature adults, but the fact remains that it is so often those of a similar age to you who develop extraordinary computer skills which, as with you, can then be abused".
Dr Tim Rogers, the psychiatrist, found in his report on Duke-Cohan that the teenager "alluded to ordinarily hidden feelings of insecurity, shame, vulnerability and humiliation that had given rise to fantasies of (and a search for) success, power, acclaim from prominent hackers and the achievement of wider online notoriety".