• In the wake of the September 11, 2001 terrorist attacks, the U.S, and many foreign countries completely overhauled their rules regarding airline security. The U.S. created the Transportation Security Administration (TSA) in November 2001 and gave it wide-ranging powers to make and enforce rules. One of those rules put in place after the attacks was a complete ban on knives in the passenger cabin.
  
  

Carrying on Knives

• As of February 2010, knives of all types are absolutely prohibited in the passenger cabin under all circumstances. This regulation applies to steel knives, utility knives, razor blades, silverware and all other types of knives, large or small. The only types of knives that a traveler can bring on planes are plastic or round-bladed butter knives.
  
  

Checking Knives

• You can have knives in your checked baggage, as long as you declare them and don't put them in your luggage until you check in. Any knives checked, whether inside luggage or kept separate, must be covered with a plastic sheet or sheath, so that they cause no harm of any kind, intended or accidental, to other passengers.
  
  

Violations

• The TSA says on its website that it rarely imposes penalties on those who inadvertently attempt to board a plane with a prohibited knife. In those cases, authorities usually simply ask such passengers to surrender the object at airport security. However, when passengers are uncooperative with the security staff, behave suspiciously or have larger or more ominous knives, they may face stiff penalties, which can include criminal charges and civil penalties up to $10,000 per infraction.