The nation's aviation-security chief said Tuesday that he still intends to let passengers carry small knives on commercial flights and that the controversial rule could be implemented soon.

John Pistole, administrator of the Transportation Security Administration, told the Inquirer Editorial Board that the policy could be put into effect as soon as "next week or the following week."

Later, he said it would more likely be "in the next 30 days."

A storm of protest from flight attendants, air marshals, and several major airlines had stalled the move. TSA delayed activating the new regulation April 25 after members of Congress asked Pistole to consider additional input from a federal advisory committee that includes aviation-related interests, passenger advocates, and others.

Pistole, a former deputy director of the FBI, said he has met with most of the groups and, barring new information, was prepared to implement the change. He said that he expected input from one group Wednesday, and that he planned to meet with the TSA employee union.

"Absent new information, I'm planning to implement it, but I want to make sure I've gotten all the input that is reasonable," he said.

A small knife is not going to cause catastrophic failure of an aircraft, but an explosive device will, Pistole said.

"All the intelligence chatter is terrorists are committed to blowing up either a U.S.-bound plane or get on a plane here at one of 450 airports and say, 'You can't stop us,' " he said. "It comes down to making sure we find explosives and not be distracted by other things."

Small knives were banned, along with other sharp objects, after the Sept. 11, 2001, terrorist attacks. In 2005, the ban was relaxed after cockpit doors were reinforced and pilots were trained to carry guns.

Currently, passengers may carry four-inch scissors, knitting needles, and small hand tools such as screwdrivers in the cabin. The potential threat has shifted to terrorists' attempting to bring down planes with bombs.

"Are we trying to provide a 100 percent crime-free environment in the cabin of the aircraft? I don't think that is TSA's job," Pistole said.

American Airlines' flight-attendants union recently released results of a national survey that found 90 percent of 1,206 respondents favored the current restrictions on knives.

TSA confiscates 2,000 knives a day at airports. Almost anything on a plane can be wielded as a sharp object, Pistole said: metal knives and forks served with meals in first class; shattered wine bottles; credit cards broken in half.

"If there's a passenger who's been drinking too much and breaks bad, should TSA be responsible for that?" he asked. "These aren't terrorists. These are people who drink too much, or they are mad at the airlines, or maybe TSA, or their spouse, or their dog. Those are the people who have confrontations on aircraft."

Pistole met Tuesday with business leaders and Mayor Nutter. He announced that TSA's pre-check program, now available to select US Airways Group travelers at Philadelphia International Airport's Terminal C security checkpoint, will be expanded June 3 to Delta, United and Alaska Airlines in Terminals D and E.

The way the program works: Airlines' most elite frequent fliers, those with the most miles, may leave their belts and shoes on and laptops, liquids and gels in their carry-ons. At check-in, passengers learn whether they qualify for expedited screening either through bar codes or printed information on their boarding passes.

In September, Philadelphia was the 24th airport to get the pre-check program, now in place at 40 U.S. airports, and 10 million passengers have participated, Pistole said.