Pistole said the TSA sought to distinguish small pocketknives, such as those equipped with corkscrews, from sturdier knives used primarily as weapons.

CNN: March 7, 2013 -- Updated 0312 GMT (1112 HKT)

Pocketknives will be allowed if the blade is no longer than 2.36 inches (6 centimeters), which is shorter than the 4-inch blades that were allowed at the time of the 2001 attacks.

CNN: March 7, 2013 -- Updated 0312 GMT (1112 HKT)