You might think that with all the security measures in place to keep the bad guys from harming us, that the terrorists would look elsewhere... like to smaller planes.
So is that a threat?
Experts say it's not. Remember in January 2002 when a teen purposely flew a plane into a building in downtown Tampa?
The pilot was the only one killed, and not much in the way of major damage. That's one of the reasons some experts say a small recreational place wouldn't be a real attractive tool for terrorists.
Still, don't think that the smaller airports, like Wausau Downtown Airport, are taking security lightly.
"Our eyes and ears are open to anything suspicious and we know the general public and our feelings about terrorism, and don't want it to happen here more than anyone else does," says manager John Chmiel.
One way to keep things safe is sort of a neighborhood watch program. The Transportation Security Administration says there's always someone keeping an eye on activity.
"It's a very small community, a small close-knit community, and the pilots really know the other pilots at the airport," says Amy Von Walter. "They're familiar with the people who do business there each and every day. They're definitely aware of what's going on at that airfield."
We have heard of terrorists expressing interest in using crop dusters to spray chemicals, but Chmiel says the damage would be too localized to do as much harm as they'd want.