“Airport perimeter security (pdf) involves multiple layers of integrated processes, procedures and technologies to detect and mitigate breaches,” according to the Airports Council International.

But that doesn’t stop visitors from regularly being where they shouldn’t. The Associated Press surveyed 31 of the busiest airports in the United States, including five in California, and found 268 incursions between 2004 and 2014. Eighty-two of them were in California.

San Francisco International Airport had the most, 37, and Los Angeles International Airport (LAX) was third, with 24. Mineta San Jose International Airport was fifth, at 18, but the San Francisco Chronicle noted that five of those were in the last 11 months. San Diego International Airport had three. Oakland’s airport was too small to be included.

LAX’s numbers were inflated by a mentally ill man who scaled the perimeter fence eight times in less than a year. He got to the jet stairs twice.

The breaches catalogued by AP were not very sophisticated and were perpetrated by drunks, mentally unstable people, folks who were lost, some opportunists looking for a shortcut and goofballs. None involved terrorism.

But the breaches are still not insignificant. “This might be the next vulnerable area for terrorists as it becomes harder to get the bomb on the plane through the checkpoint,” airport security expert Jeff Price told AP.

The 31 airports handle two-thirds of the nation’s commercial traffic but not every big airport was included. AP said Honolulu and Las Vegas did not have complete data and Boston's Logan and the New York City area's three main airports declined to participate.

More than half the breaches occurred at seven airports in four states. Philadelphia was second to S.F. with 25, followed by Los Angeles (24), Las Vegas (21), San Jose (18), Miami (14), Tampa (14), Phoenix (12), Minneapolis-St. Paul (10) and Denver (8).

AP did its own survey because official information from the Transportation Safety Administration (TSA) is scant. Unlike airport checkpoints, which are controlled by TSA, individual airports are responsible for perimeter security. They feed information on breaches to the federal Department of Homeland Security agency, but the data is not complete and not available to the public.

AP has been fruitlessly waiting a year for TSA to respond to a Freedom of Information Act request for documents. But the news agency reported that TSA told Congress in 2011 that there had been 1,388 perimeter breaches at 450 airports since 2001.

AP began its survey after 15-year-old Yahya Abdi scaled a fence at the San Jose airport, walked out onto the tarmac, climbed inside a jet’s wheel well and hitched a ride to Hawaii. He survived the six-hour flight.

Abdi was one of five intruders who made it all the way on to a plane. At least 44 reached an area where planes are fueled or load passengers. Most breachers are caught within 10 minutes but some are on the loose for hours. One made it into a wheel well in 2010 and died when he fell out on approach to Boston’s airport.

–Ken Broder

To Learn More:

Report: SFO, San Jose Airports Among Tops in Perimeter Breaches (by Martha Mendoza and Justin Pritchard, Associated Press)

S.F. Airport Had Most Breaches into Restricted Areas, Study Finds (by Evan Sernoffsky, San Francisco Chronicle)

“It Could Happen Anywhere” (by Mike Hendricks, Kansas City Star)

A Little Sensitive Over “Sensitive” Airport Security Numbers (by Noel Brinkerhoff, AllGov)

Airport Perimeter Security (Airports Council International) (pdf)