Three Britons were found guilty on Monday of plotting to kill thousands of people by blowing up transatlantic airliners bound for North America, in mid-flight suicide attacks using bombs made from liquid explosives.
The suspected al-Qaeda plot, just days from being put into operation according to British detectives, had huge worldwide ramifications leading to tight restrictions on the amount of liquids passengers could take on board aircraft.
Four other men were found not guilty of the plot and the jury failed to reach a verdict in the case of an eighth suspect, Britain's Press Association reported.
The bombers intended to simultaneously destroy at least seven planes carrying over 200 passengers each between London's Heathrow airport and the United States and Canada in August 2006 using explosives hidden in soft drink bottles, prosecutors said.
Once aboard, the authorities would have been powerless to stop their plan from being put into action.
But the conspirators were caught following the largest surveillance operation carried out by British police.
"If they had been successfully deployed, they would have killed thousands of people on board and maybe more if they had detonated them over land," said a senior British police source, speaking on condition on anonymity.
US officials have said the carnage would have been as horrific as the Sept. 11, 2001 attacks on New York and Washington that killed 3,000 people and had huge repercussions for the aviation industry.
Prosecutors said the plot centered on seven flights from Heathrow's Terminal 3, each capable of carrying between 241 and 285 passengers.
But recorded conversations between some of the men, British Muslims aged in their 20s at the time, suggested other terminals and possibly 18 suicide bombers might have been involved, while targets such as gas terminals and oil refineries were mentioned.
The plot was hatched in Pakistan just months before the men were arrested in August 2006. Police suspect that al-Qaeda planner, Egyptian Abu Obaidah al Masri, who some media reports have cited as the inspiration for the deadly July 7, 2005 suicide bombings in London, was the mastermind.
The British ringleader was Abdulla Ahmed Ali, 28, while Assad Sarwar, 29, gathered the bomb ingredients at his home in High Wycombe, a town west of the capital.
At a previous trial last year, Ali, Sarwar and Tanvir Hussain, 28, were found guilty of conspiracy to commit murder but the jury failed to agree on whether they had intended to blow up planes.
The guilty men will be sentenced at a later date.