When a gang tried to steal £33m worth of gold, diamonds and cash from a Heathrow cargo warehouse last year, around 100 police officers were lying in wait.
Police had to assess the risk of letting the raid go ahead
How did detectives thwart what would have been one of Britain's biggest heists?
Police from the flying squad and specialist firearms unit swooped shortly after the gang ram-raided their way into the airport's Swissport Cargo Warehouse in a white Mercedes van in May 2004.
Police said they had been under surveillance for "some time" - thought to be weeks - after the Met's flying squad had mounted an undercover operation based on intelligence on the gang's plot.
Detectives would not reveal exactly how they knew of the raid but have paid tribute to the wider investigation into high value crimes at Heathrow - Operation Grafton - which has seen police working closely with the airport's owners, businesses and local police forces.
Thirteen days before the raid, the gang carried out a "dry run" or perhaps an aborted attempt at the robbery, said the judge during sentencing on Friday.
The men knew when to expect consignments coming into the warehouse.
As the real raid date approached the Flying Squad had to weigh up letting it go ahead for the chance to catch the robbers red-handed, against the risk of putting the warehouse staff in potential danger.
"Each time we look at the risks and how we will manage those risks," said Det Supt Barry Phillips.
"If we can't manage them we will frustrate the crime [stop it before it happens] and not allow anybody to be put at risk."
The decision was made that some Swissport managers would be given advance warning the raid was going to take place, but for "operational reasons" the information could not be shared with the rest of the workforce.
From the beginning, due to the nature of the raid, the gang was believed to have had inside information about the warehouse.
Det Supt Phillips said the gang had known where the gold bullion was and "went straight for it".
But all the planning and preparation the gang apparently put in proved fruitless because the famous Met Police team - the basis for 1970s TV series The Sweeney - stayed one step ahead.
FOILED HEIST AT HEATHROW
1 1000 BST: Armed gang ram warehouse shutters in a van and threaten staff. They are trying to steal more than £30m in gold bullion, diamonds and cash.
2 Police lying in wait disable the van and arrest six of the gang.
3 Another van is hijacked by Steven Nolan and driven off towards Stanwell.
4 1300 BST: Steven Nolan arrested at his home.
When the raiders reversed at speed into the shutters of the warehouse at 1000 BST on 17 May 2004, they had each expected to drive away at least tens of thousands of pounds richer.
As his accomplices loaded boxes of gold onto the van, Chris Smith ran into a secure area and demanded one of the warehouse workers tell him where the "black bags" were kept, which contained the cash they were targeting.
This was further confirmation for the police that the gang had a contact inside.
"Only someone who worked there would have known it [the cash] came in black bags," said Judge Edward Southwell.
As the others began to load the gold, after violently threatening warehouse staff, they were faced with police officers coming from every direction.
The officers fired Hatton rounds - special bullets designed to deflate tyres with minimal damage - to prevent them escaping in their getaway van.
Caught red-handed, six of the eight men - one of whom was still wearing a security tag following his release from a young offenders institution - were searched and handcuffed.
The raiders' van was reversed at high speed into the warehouse
Steven Nolan's escape in a lorry hijacked just after it made a delivery to the warehouse has left its driver, Andrew Mills, in a "highly distressed and emotional state", the court was told.
A panicking Nolan forced him to drive the 17.5 tonne lorry along the M25 to Wraysbury, Berks, barging through traffic and hitting at least one vehicle.
Mr Mills can "barely keep it together", finds it difficult to sleep and says his whole family has been badly affected, said the judge. For this Nolan was given an extra six months in prison.
For the robbers, the whole plan went disastrously wrong. Rather than fulfilling their ambitions of pulling off a potentially spectacular heist, the men will join the list of failed robbers caught in the act.
The Flying Squad operation was down to "superb police work", "true intelligence sharing" and courageous officers, said Det Supt Phillips, who was present at the raid.
"I've been doing this for many years. It was a well executed, classic Flying Squad ambush. It had always proved to be extremely effective, using speed, surprise and skill.
"And there's still some adrenaline there, even after 30 years in the job."