The Air Line Pilots Association pressed Congress Tuesday to allow pilots to carry firearms in cockpits, a move the union says could prevent hijackings.

"It is probably safe to say that the entire aviation industry ... enjoyed a false sense of security before Sept. 11," Capt. Duane Woerth, the union's president, told the House Transportation aviation subcommittee. "We must replace that false sense of security with a genuine sense of security."

Woerth told the committee that the bullets used would "disintegrate on impact" so they would not be a danger to the aircraft. He said stun guns would also be made available under the union's proposal.

Congressional reaction was mixed. House Majority Leader Dick Armey, R-Texas, said, "Stun guns are something I could have more of an affinity for" than ordinary guns, although Armey added that he was still open-minded on the issue.

Union spokesman John Mazor called the proposal "a reflection on how much the attack on Sept. 11 has changed everything we thought about hijackings and terrorism."

He said armed pilots in cockpits would be a radical step for the union, but the idea is supported overwhelmingly by its pilot members.

"Under the old model of hijackings, the system worked well. That strategy was to accommodate, negotiate and do not escalate," Mazor said. "But that was before. The cockpit has to be defended at all costs."

Woerth was asked on ABC's Good Morning America about fears a bullet could penetrate a plane's walls and depressurize it. The bullets that would be supplied to pilots "basically come apart at first impact," he said. "They're very destructive to human tissue but it's very unlikely that would do any serious damage to the fuselage and not such that would cause a depressurization problem."

The Federal Aviation Administration prohibits pilots from being armed.

The union envisions an armed pilots program that would be strictly voluntary and would require extensive background screening and psychological testing of pilots. Pilots also would receive classroom and practical training in the use of firearms that would be equivalent to what armed sky marshals receive.

The union has asked the FBI to handle the program and training and is awaiting a response, Mazor said.

"These men and women operate $100 million pieces of equipment. They can sure learn to operate a .38 snub-nose if they want to," said aviation consultant Michael Boyd of the Boyd Group in Evergreen, Colo.

"I'd rather have the gun in the hand of the pilot than the gun in the hand of some guy ... who wants to kill people," he said.

The union has urged pilots to act aggressively in terrorist situations. For example, all cockpits are equipped with a crash ax. The union advised its members that they should consider using it as a weapon in a suicidal hijacking.

"The pilot must be prepared to kill a cockpit intruder," say the union's guidelines that were revised after the Sept. 11 attacks.

The union also is exploring new standards for secure cockpit doors to protect the flight crew against attacks.

ALPA represents more than 67,000 pilots at 47 airlines in the United States and Canada. It is based in Herndon, Va.