American Airlines strengthening cockpit doors

FORT WORTH, Texas (CNN) -- American Airlines said Tuesday it plans to place reinforcement bars on all of its cockpit doors within 30 days to prevent hijackings similar to those on September 11 that destroyed the World Trade Center and heavily damaged the Pentagon.

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Two of the four hijacked planes used in the attacks were American Airlines planes. American Airlines Flight 11 was the first jet to slam into the World Trade Center; American Airlines Flight 77 crashed into the Pentagon.

"The devices were designed by American Airlines' engineers working around the clock since Sept. 11 to meet the challenge of providing additional cockpit security," the airline said in a statement. "The company has designed the locking devices as a measure to immediately secure the cockpits while the FAA explores ways to further enhance cockpit security."

The airline said the Federal Aviation Administration had approved the new cockpit reinforcement bars and that it was moving ahead with plans to put the devices in all of its aircraft, as well as all aircraft flown by TWA.

American Airlines said it has already installed prototypes of the devices on an MD-80 and a Boeing 757. The airline said it is sharing its plans for the locking device with other U.S. carriers.

An airline security task force, composed of representatives from airlines, aircraft makers, pilots and flight attendants unions, has made several recommendations to the FAA to make flying safer.

The recommendations include "deadbolt, crossbar, a net or other barrier devices" on cockpit doors, similar to the device American has designed for its doors; developing a way for flight attendants to notify pilots of a suspected threat in the cabin; having the industry evaluate the use of cameras and lighting outside the cockpit; and giving crew members access to "non-lethal defensive capabilities" to be used in hijack emergencies.