Story highlights TSA sought to relax rules banning small knives on commercial flights

Plan never took effect following strong criticism from Congress, airlines, unions

The ban on small knives was imposed after the 2001 al Qaeda hijack attacks

Experts say small knives pose little threat to aircraft

The Transportation Security Administration on Wednesday abandoned plans to allow small knives and certain other banned items back on passenger flights, surrendering to fierce criticism from airlines, unions and Congress.

In a statement, the TSA said it would continue to enforce the "current prohibited items list," which does not permit small knives.

The TSA first announced the plan to allow small knives and sporting equipment in March, saying doing so would permit airport screeners extra time to focus on more dangerous objects like bombs and related components.

The change would also have brought the United States into alignment with rules governing flights in most other countries, he said.

Aviation safety experts said small knives and sports equipment present little threat to aircraft, largely because of the reinforced cockpit doors.

TSA chief John Pistole

Authorities say terrorists continue to plot against airlines. But the threat response has shifted away from any effort to take control of a plane, like the 9/11 hijackers did, as carriers have hardened cockpits and beefed up on board and ground security.

Knives are among the most common items surrendered by passengers at screening points at U.S. airports, figures show. But aviation safety experts say small knives and sports equipment present little threat to aircraft.

The emphasis now is on detecting bombs.

TSA Administrator John Pistole previously said "our greatest concern, the greatest risk" is non-metalic improvised explosive devices, or IEDs.

"That's what I want our security officers to focus on," he said.

But his effort to roll back the small knife ban to allow unfixed blades no longer than 2.36 inches and less than a half-inch wide was met with sharp and sustained criticism from big airlines.

Groups representing flight attendants, pilots, and airport screeners also were not convinced that the security situation warranted a change. Numerous members of Congress balked at the plan as well, some promising to fight it legislatively.

TSA pulled back three days before the change was to take effect in April, saying it wanted to consult with key groups before moving forward.

TSA officially abandoned the effort on Wednesday.

"TSA strongly values the input of our partners and traveling public and appreciates the varying points of view shared throughout the review process," it said in its statement.

It made the final decision "after extensive engagement" with aviation advisers, law enforcement officials, and passenger advocates, the agency said.

Some Pistole supporters, including former TSA chief Kip Hawley, argued the knife ban actually endangers passengers by re-focusing the attention of airport screeners away from bigger threats.

But that opinion held little sway with flight attendants, who said they would be "sitting ducks" for any passenger armed with weapons.

"We promised 'no knives on planes ever again' and today that promise was kept," the Coalition of Flight Attendant Unions said in a statement.

It commended the agency for revising its plans.

"The result is better security policy and the assurance that our nation's aviation security system continues to be vigilant for knives that could be used in a terrorist attack or criminal act against passengers or crew," the group that represents 90,000 flight attendants said.

The TSA has made numerous changes to its list of prohibiting items over the years. It now permits small screwdrivers, small scissors, cigarette lighters and matches, and bans large quantities of liquids and gels.

Rep. Bennie Thompson of Mississippi, the top Democrat on the House Homeland Security Committee, applauded the TSA decision.

"When established processes for creating policy are followed, common sense prevails," he said.