By Andrew Walker  BBC News Profiles Unit

The Metropolitan Police Flying Squad's Heathrow coup is only the most recent in a long line of high-profile successes for the rapid-response mobile unit.

"Shut it!": Jack Regan in familiar form

From the Kray twins to Kenneth Noye, the Sweeney, whose nickname comes from Cockney rhyming slang (Sweeney Todd - Flying Squad), has been at the centre of British criminal for 80 years.

The squad was formed in 1919, as the Mobile Patrol Experiment, in response to growing concern about an influx of crime from overseas into the capital.

Officers conducted operations from the back of two horse-drawn, canvas-covered, Great Western Railway vans, a far cry from the high-powered saloons which, to most people, epitomise the force today.

The first police force to use cars, the group's original 12 detectives were allowed to pursue criminals into any police division area, thus becoming known as the "flying squad".

Legendary

Over the years, the unit became involved mainly in preventing robbery and combating organised crime. Its own armed officers, or "thief-takers" as they proudly classed themselves, became legendary.

There was Leonard "Nipper" Read, who ended the Kray twins' reign of terror over London's East End and Jack Slipper, nemesis of the 1963 Great Train Robbers and a constant thorn in the side of the fugitive Ronnie Biggs.

In popular mythology, the Flying Squad was immortalised by the 1970s television series, The Sweeney.

Success: The Flying Squad foiled a £200m jewels heist in 1999

The show's -edged, -paced style won millions of fans, enthralled by car chases with Ford Granadas and Mark II Jags, seedy criminals' wives, and John Thaw's world-weary Detective Inspector Jack Regan with his trademark admonition: "Shut it!".

The unit's officers have always been noted for their knowledge of the underworld. Extensive contacts with paid have been the jewel in the crown of the squad's intelligence operations for years.

Sometimes, however, this close relationship with the criminal fraternity has backfired, with truly disastrous consequences.

Scandal

The 1970s was a dark period for the Flying Squad. An internal police investigation, Operation Countryman, revealed an extensive and tangled web of . Bribery was endemic, especially between officers and Soho pornographers.

Jailed: Bomber David Copeland

In a which still resonates today, the head of the Flying Squad, Chief Superintendent Ken Drury, was jailed along with 12 other Scotland Yard detectives, for accepting bribes.

In 2001, three Flying Squad detectives were each jailed for seven years after 'springing' a police informant from prison in order to carry out a raid on their behalf.

But there have been great , too. Most recently when the squad's officers arrested David Copeland, the Brixton nail bomber who killed three people and injured 70 when he blew up the Admiral Duncan pub in Soho in April 1999.

More women

The squad also spectacularly foiled an attempt to steal diamonds worth £200m from the Millennium Dome in November 2000.

Even though the unit's work has become as high-as the rest of society, with computers rapidly transforming the policeman's lot, Flying Squad officers still face considerable dangers.

They are specialists in the "pavement ambush", swooping on armed robbers while they are committing a crime. Though their sheer speed usually wins the day, it is a high-risk form of policing, not for the faint-hearted.

New boss: DCS Sharon Kerr, head of the Flying Squad

But the Squad, now integrated into the Organised Crime Group, an élite unit which tackles major criminals, has recently undergone a huge change, recruiting more women, including its new chief, Detective Chief Superintendent Sharon Kerr.

Det Supt Kerr said the Flying Squad was not institutionally , but added: "I do think there's more that can be done encouraging women to reach out and try something different.

"My challenge is to get more women to see it as a valuable profession. I didn't have to smash any glass ceiling to get here."

So the image of the Sweeney as the haven of the rugby playing, beer-swilling bruiser may have gone forever, replaced by a more family-friendly, feminine, post-modernist Flying Squad.

What would Jack Regan make of that?