A Typhoon fighter jet

Royal Air Force Station Northholt (England), Aug. 2: More than 70 years after squadrons of Spitfire and Hurricane fighters flew from here into an epic air battle with Hitler’s Luftwaffe, pilots flying the fastest fighter interceptors in Britain’s modern arsenal have been cast in a similar role.

But instead of waves of German bombers in the Battle of Britain, these pilots are guarding against a more elusive enemy: terrorists who might seek to rain destruction on the Olympic Games from the air.

While the pilots are loath to talk about the threat, officials acknowledge that they have prepared for a nightmare situation in which terrorists hijack an airliner or executive jet and try to fly it into the 80,000-seat Olympic Stadium or one of the other 30 or more spectator-packed sites around the capital. The spectre of the September 11, 2001, attacks on New York and Washington hangs over the operation, and the lessons learned from those attacks are central to the planning of the mission here.

At the Northolt airfield on London’s western fringe — best known in more recent times as the airfield where Princess Diana’s coffin was brought to England after her fatal car crash in Paris in 1997 — at least one pilot is strapped into the cockpit of a $200 million, 1,400-mile-an-hour Typhoon fighter at all times, day and night.

With helmet, pressure suit and gloves on, the pilot has a no-fail mission: to scramble in an instant to intercept — and, if necessary, shoot down — any aircraft posing a threat to Olympics installations. “It’s a very short tether we’re on,” Squadron Leader Gordon Lovett, 37, commander of the Royal Air Force’s No. 3 Squadron, said in his flight overalls as one of six Typhoon pilots deployed with the four fighters assigned to the Northolt mission.

He described the operation as mainly one of deterrence, to pose a sufficiently formidable threat that would make any would-be attackers realise that their chances of a successful strike were practically nonexistent.

“Hopefully, they won’t even think about it,” he said.

He warned that there should be no doubts of the Typhoon’s ability to shoot down any aircraft that failed to respond to radio warnings, flares, lasers or pilot-to-pilot hand signals to divert intruders away from London to a landing elsewhere. The decision to shoot down a plane, he said, would be taken at what military commanders have called “the highest authority”, meaning Prime Minister David Cameron.

“We’re quite blessed in not having to make the decision for ourselves,” Squadron Leader Lovett said. “Conscience wouldn’t have much time to get a foot in the door. It would all be over very quickly, before you’d had time to think about it.” Organisers of the last two Summer Olympics, in Beijing and Athens, adopted similar air defence plans, deploying military aircraft and, as in London, batteries of ground-to-air missiles in a ring around the main Olympics sites. In London’s case, that includes two missile detachments on high-rise rooftops near the Olympic Park in East London and four others set in open parkland about a mile away.

What has raised concerns in London is that Britain has been listed by its own security and intelligence agencies as being at high risk of a catastrophic attack by Islamist militants, partly because of its alliance with the United States in the wars in Afghanistan and Iraq, but partly, too, because of the large number of terrorist cells known to be active in the communities where Britain’s one and a half million Muslims live.

RAF officials say that with years to plan since the Games were awarded to London in 2005, they have had time to fashion a shield not only against hijacked airliners, but also an array of other airborne threats. These, they say, include light aircraft, hot-air balloons, fixed-wing gliders, hang gliders, microlight planes, airships, unmanned drones and even remote-controlled model aircraft capable of carrying small bombs.

The main defence against lighter, lower-altitude and slower threats consists of sniper-carrying helicopters based at an army base in Ilford, east of the Olympic Park, and aboard the Ocean, a Royal Navy helicopter carrier moored in the Thames a couple of miles south of the park. Military commanders believe that with the Typhoons, the Puma and Lynx helicopters and the Starstreak missile batteries, they can deal with any airborne threat, at any altitude, in minutes.

The Royal Air Force’s state of readiness was demonstrated last week when a Typhoon was scrambled from Northolt to intercept a Boeing 757 airliner flying at 30,000 feet over the coast of Brittany, in northern France, after the aircraft failed to respond to British air traffic controllers for a few minutes. The aircraft, carrying more than 240 passengers and crew on its way from Tunisia to Glasgow, finally identified itself as it flew over the English Channel.

By that time, the Typhoon, climbing above 15,000 feet less than a minute from takeoff, was well on its way to challenge the airliner.