VOA常速英語: 保持華盛頓領(lǐng)空安全是艱巨的任務(wù)

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WASHINGTON—Being the home of all three branches of the U.S. federal government makes Washington, D.C., the prime target for those who want to make their messages and ideas heard. Unfortunately, many of them choose to deliver them in unorthodox ways, including from the air, as a recent incident clearly showed involving a gyrocopter landing on the Capitol’s West Lawn.

When Florida Postal Service worker Doug Hughes landed his homemade gyrocopter on the west lawn of the U.S. Capitol, in a daring bid to deliver a political message to the lawmakers, the security services were taken by surprise.

He was quickly surrounded and taken away by police, his aircraft was checked for explosives, and now he faces several years of prison.

But his stunt highlighted once more that the airspace around most of the public buildings is easily penetrated by drones and light piloted aircraft, too small and flying too low to be safely prevented from reaching their goals.

Difficult detection

John Hansman a professor of Aeronautics and Astronautics at Massachusetts Institute of Technology, said small, flying vehicles are not easy to detect and stop.

“If you have a very small target, like a gyrocopter, which doesn't have a very large radar cross-section, so it's not reflecting much energy back, and it's close to the ground, you might get some signal coming there, but you may actually think it's a building or a car moving on the ground, not a helicopter," he said.

Hansman noted that heavy traffic in downtown Washington makes it even more difficult.

“If you have a complex environment like an area around Washington where you have lots of other vehicles on the ground, you have vehicles in the air, and you have something very small like this, it's actually not that difficult for it to slip through the protection,” said Hansman.

Inadequate systems

The chairman of the American Leadership and Policy Foundation, David Stuckenberg, is a former military pilot who writes about the airspace security. Speaking via Skype, he said the present safety systems are inadequate.

“We need to understand that we've been lucky and as technology increases and as drones proliferate people will increasingly look at these as weapons of opportunity or technologies that can be adapted for ill intent,” he said.

Stuckenberg said a lot more needs to be done before such systems are in place, such as conducting thorough analyses and bringing new regulations.