Homeland Security warns of potential drone danger

Gravelly Point near Washington Reagan National Airport is a plane enthusiast's dream, but for others it can spark concern.

"Looking out the window hopefully not to see a drone. Obviously that's the big scare right now," said airline passenger Robert Escobar.

In a threat assessment issued to law enforcement, the Department of Homeland Security is warning of "potential security vulnerabilities" of terrorists trying to use drones as part of an attack in the U.S.

It is illegal to fly drones near airports, but aircraft at JFK Airport in New York reported drones within eyesight three times in three days.

"There is a distinct possibility that this sort of thing could happen," said Michael O'Hanlon with the Brookings Institution.

While terrorists have tried for years to bring down planes with an explosive from the inside, O'Hanlon said drones provide a way to attack from the outside.

"Wouldn't be that hard to put a payload with explosives on it, and it wouldn't be that hard to just play roulette and try to get it in the path of an incoming airplane," O'Hanlon said.

Some airline passengers think the threat assessment goes too far.

"My husband has a drone that we use for photography and it actually allows you to do a lot of stuff," said one woman.

Another passenger said, "I'm not sure that I'd be in favor of tons of regulations regarding them."

The FAA is investigating the recent drone sightings in New York.