The man in charge of America's airline security has defended his plan to allow passengers to carry small knives on to planes, despite a growing backlash.
Transportation Security Administration head John Pistole told the House of Representatives Homeland Security Committee it was unlikely in these days of hardened cockpit doors and other preventative measures that the small folding knives could be used by terrorists to take over a plane.
But he also noted that searching for the knives on passengers or in their carry-on bags was time consuming. TSA screeners confiscated about 2,000 such knives every day, with each incident taking about two to three minutes, he said.
"I think the decision is solid and it stands and we plan to move forward," Mr Pistole said.
The policy, which goes into effect on April 25, has sparked strong opposition from flight attendants, government air marshals, some pilot unions, and even aviation insurers. In the hands of the wrong passengers, the knives can be used to harm flight attendants and other passengers, critics say.
Several airline chiefs have also expressed qualms. In a letter to Pistole last week, Delta Air Lines chief executive Richard Anderson said he shared the "legitimate concerns" of the airline's flight attendants. US Airways chief Doug Parker has asked the TSA administrator to reconsider his position.
Several members of the House committee also urged Mr Pistole to drop the proposal, warning that Congress may take steps to block the policy change.
Since the September 11 2001, terrorist attacks there have been no incidents in which terrorists have successfully used sharp objects to take over a plane, which suggests the current policy of keeping even small knives off planes is working, committee members said.
"How does allowing sharp objects on board now accomplish maintaining the goal of having zero planes taken over?" asked Democratic Rep Eric Swalwell. "I'm asking why now, and why do we want to go back?"
The lack of instances in which terrorists try to use knives to take over a plane underscores that their tactics have shifted to using explosive devices instead, which what TSA is devoting its energies to finding, Mr Pistole said.