SAN DIEGO -- The 10News I-Team's van is not behind a gate looking into Montgomery Field.

The I-Team is not on a plane getting ready to take off.

The van is on the ramp and no one stopped them.

10News teamed up with Bob Hulse, an aviation safety consultant.

"I'm a retired airline pilot and retired military pilot," said Hulse.

With Hulse's help, the I-Team attempted to gain access to the four most active general aviation airports in San Diego County, hoping to find out just what has changed since the 9/11, when America's airports appeared the most vulnerable.

The I-Team tested Montgomery Field, an airport that averages roughly 670 flights a day, most in all of Southern California.

The I-Team tagged behind a car that drove through the security gate.

"The gate didn't close behind us because the person behind us came in, too," said 10News' Kerstin Lindquist. "We were followed by someone else."

The I-Team not only drove up to the runway, but even got out and walked around.

"No one has come up and asked us what are you doing ... not one person has stopped us or even asked," said Lindquist.

At Gillespie Field, there is an average of 665 flights a day.

The story is the same, as the I-Team drove right into the secured areas through an open gate.

The I-Team tried a second gate at Gillespie, and this time, after getting out and walking around, they are questioned.

Employees were courteous but not concerned.

"We got stopped but not questioned too thoroughly," said Lindquist.

Brown Field is the smallest of San Diego's airports. They only see about 277 flights a day.

Unfortunately, Brown Field was by far the easiest to get into. Many areas were not even gated and the I-Team was able to walk right up to many private planes.

However, the I-Team was quickly questioned by a curious pilot.

All small airports run independently, not by the Transportation Security Administration or even the Federal Aviation Administration. The FAA, however, "strongly recommends that all airport operators install secure fencing …"

The small airports rely on its tenants to be a neighborhood watch, of sorts. That is why the Aircraft Owners and Pilot's Association issued a warning of a "clear and present danger to general aviation" and urged airport personnel "to make access difficult for people who don’t belong."

McClellan-Palomar Field is the one airport on the list that does have commercial flights and the only airport with TSA security.

It was the most secure, with gates having combination locks and getting in was not as easy as following behind the car in front.

However, it wasn't without its holes.

The I-Team found places where someone could easily climb over gates or construction areas with gates wide open.

Lindquist asked Hulse, "If someone wanted to go steal an airplane at Palomar, how easy would it be?"

Hulse said, "I think you could probably get it done."

It could be done, but would it be done?

10News notified each airport in the investigation and airport operators were quick to respond, saying security at general aviation airports in San Diego is constantly evaluated in relation to the threat.

At this point, they don't see access to a little plane as a major risk to Americans -- something Hulse agreed with, up to a point.

"You're going to have to know how to fly it, have access to it and if you are going to do it, why not just buy one of these?" said Hulse

It is almost exactly what was done in San Diego -- terrorists trained to be pilots at Montgomery Field.

Now seven years later, very little is keeping them from showing up at any one of these airports again.