Aviation Security: TSA's Change to Its Prohibited Items List Has Not Resulted in Any Reported Security Incidents, but the Impact of the Change on Screening Operations Is Inconclusive

The alleged August 2006 terrorist plot to detonate liquid explosives onboard multiple commercial aircraft bound for the United States from the United Kingdom has highlighted both the continued importance of securing the civil aviation system and the potential that improvised explosive devices (IED) may be smuggled onboard passenger aircraft. The Transportation Security Administration (TSA) has primary responsibility for ensuring the security of civil aviation, which includes the safety of passengers and flight crew. One measure TSA uses to protect the aviation system is prohibiting individuals from carrying items that it determines to be a threat to the aircraft and its passengers into an airport sterile area or onboard an aircraft either in their carry-on bag or on their person. To implement this measure, TSA maintains a prohibited items list that informs both the Transportation Security Officers (TSO) who conduct passenger screening and the traveling public of items that will not be allowed into an airport sterile area or onboard an aircraft. In December 2005, TSA revised its prohibited items list to allow passengers to carry: (1) metal scissors with pointed tips and a blade 4 inches or less in length as measured from the fulcrum; and (2) tools--such as pliers, screwdrivers, and wrenches--7 inches or less in length (excluding crowbars, drills, hammers, and saws). TSA considers any incident that threatens the security or safety of an aircraft or its passengers and flight crew to be a security incident. These could include a range of activities onboard an aircraft such as disruptive passenger behavior, violence against a passenger or crew member, hijacking attempts, or the use of an improvised explosive device. By examining the security impacts of the change to the prohibited items list, this report considers the impacts that could result from a passenger attempting to use scissors or tools to hijack an aircraft or to commit other forms of violence onboard a flight. Such actions fall within TSA's statutory responsibility to ensure the safety and security of passengers and crew aboard aircraft. In accordance with Conference Report 109-699, which accompanied the fiscal year 2007 Department of Homeland Security (DHS) appropriations act, this report addresses the following questions: (1) What was TSA's basis for removing certain scissors and tools from the prohibited items list and what are stakeholder views on the change? (2) What have been the impacts, if any, of the removal of certain scissors and tools from the prohibited items list on the security of aircraft passengers and flight crew and on the effectiveness of checkpoint screening operations?