A pilot who posted videos on YouTube that were critical of security at San Francisco International Airport is now the subject of an investigation, the pilot's attorney says.

The pilot placed several videos on YouTube in late November or early December that showed how ground crew members can enter secure areas by swiping security cards and without undergoing further screening.

The Transportation Security Administration is looking into whether the pilot revealed sensitive information, his attorney, Don Werno of the Santa Ana-based law firm Werno and Associates, said Friday.

The TSA wouldn't answer questions but said in a statement it is responding to the situation and is confident in the security at San Francisco International Airport.

"As to access control at SFO, TSA is confident in the tools the airport has implemented and reminds passengers there are security measures in place that are both seen and unseen."

The pilot remains employed with a major airline, but he has withdrawn from a program that trains flight crew to help prevent hijackings after authorities confiscated his federally issued firearm, Werno said. He declined to release the pilot's name, citing concerns about the man's job.

In the footage, the pilot says that pilots undergo intense screening, but then have access to ax-like weapons that are stored in the cockpit in case of emergencies.