The nine men found guilty of hijacking an Afghan airliner and flying it to Stansted Airport have had their convictions quashed at the Court of Appeal in London.
The plane was diverted to Stansted
Brothers Ali and Mohammed Safi - who had been accused of leading the hijack - were jailed for five years in January last year after telling their trial they were fleeing persecution by the Taleban.
More than 150 passengers were held for three days on the tarmac at the airport in Essex in deteriorating conditions.
The cost of the incident, including two trials, a huge police cordon at Stansted, and disruption to the airport and business, was thought to have reached £12m.
Lord Justice Longmore, Mr Justice Hooper and Mrs Justice Cox ruled the convictions were "unsafe" because the law relating to whether the men had acted under duress had been wrongly applied at their trial.
The Crown Prosecution Service has already indicated it will appeal "on a point of law" to the House of Lords once the appeal judges reveal their reasons for the ruling at a later date.
They hijacked a plane, that's certainly correct, but... they were still acting under the force of the duress
Safis' trial lawyer
Six of the other men received sentences of 30 months, with the youngest accused getting a 27-month sentence.
The Afghan Ariana Boeing 727 had been diverted during an internal flight in Afghanistan in February 2000.
The men were convicted at the Old Bailey in December 2001 of hijacking the plane, false imprisonment, possessing firearms with intent to
cause fear of violence and possessing explosives.
They had said they were escaping persecution from the Taleban regime, as they were members of a banned group called the Young Intellectuals.
Of the 165 people on the plane 74, including the convicted men, have asked to remain in the UK.
The Court of Appeal ruling means the Safi brothers, 37 and 35, the only members of the group still in custody, are likely to be released imminently.
Abdul Shohab, 21, Taimur Shah, 29, Kazim Mohammed, 28, Nazamuddin Mohammidy, 28, Abdul Ghayur, 25, and Mohammed Showaib, 26 have all been released already.
Richard Ferguson, representing the Safis, said: "There was an onus on the defence to prove duress and that's where the legal debate centred and that's really the basis of the Court of Appeal's decision."
He told BBC News 24: "The factors involved in this case were that these men were escaping from the Taleban regime.
7 Feb 2000: Airliner lands at Stansted
10 Feb: Standoff ends with surrender
18 Jan 2001: First trial begins
18 Apr 2001: First trial ends with no verdict on nine of 11 accused
Oct 2001; Second trial starts
6 Dec 2001: Nine found guilty
18 Jan 2001: The men are sentenced
"They hijacked a plane, that's certainly correct, but their case all along was that thereafter they were still acting under the force of the duress.
"They could not give themselves up at any earlier stage because of the fear of being returned to the then Taleban regime in Afghanistan and because of that the hijack was prolonged."
The original trial judge had said the men's action "was brought about by fear of death at the hand of a tyrannical, unreasoning and merciless regime".
But he argued it had changed in nature at Moscow Airport when the hijackers refused to release hostages who did not share their objective of reaching Britain.
And he said they had prolonged the 70-hour standoff at Stansted for political reasons.
The prosecution had said the men were armed with four guns, a knife and two hand grenades, and that they had threatened to kill passengers and blow up the plane.
The Old Bailey trial heard how the plane had landed in Tashkent in Uzbekistan, Kazakhstan and Moscow before the captain was forced at gunpoint to fly to Britain.