Despite the documented shortcomings of the screening system, the fact that neither a
hijacking nor a bombing had occurred domestically in over a decade was perceived by
many within the system as confirmation that it was working. This explains, in part, the
view of one transportation security official who testified to the Commission that the
agency thought it had won the battle against hijacking. In fact, the Commission received
testimony that one of the primary reasons to restrict the consequences of CAPPS
âselectionâ was because officials thought that checkpoint screening was working.
Staff Statement No. 3 8
The evolution of checkpoint screening illustrates many of the systemic problems that
faced the civil aviation security system in place on 9/11. The executive and legislative
branches of government, and the civil aviation industry were highly reactive on aviation
security matters. Most of the aviation security systemâs features had developed in
response to specific incidents, rather than in anticipation. Civil aviation security was
primarily accomplished through a slow and cumbersome rulemaking processâa
reflection of the agencyâs conflicting missions of both regulating and promoting the
industry. A number of FAA witnesses said this process was the âbaneâ of civil aviation
security. For example, the FAA attempted to set a requirement that it would certify
screening contractors. The FAA Aviation Reauthorization Act of 1996 directed the FAA
to take such action, which the 1997 Gore Commission endorsed. But the process of
implementing this action had still not been completed by September 11, 2001.
Those are systemic observations. But, to analyze the 9/11 attack, we had to focus on
which items were prohibited and which were allowed to be carried into the cabin of an
aircraft. FAA guidelines were used to determine what objects should not be allowed into
the cabin of an aircraft. Included in the listing were knives with blades 4 inches long or
longer and/or knives considered illegal by local law; and tear gas, mace, and similar
chemicals.
These guidelines were to be used by screeners, to make a reasonable determination of
what items in the possession of a person should be considered a deadly or dangerous
weapon. The FAA told the air carriers that common sense should prevail.
Hence the standards of what constituted a deadly or dangerous weapon were somewhat
vague. Other than for guns, large knives, explosives and incendiaries, determining what
was prohibited and what was allowable was up to the common sense of the carriers and
their screening contractors.
To write out what common sense meant to them, the air carriers developed, through their
trade associations, a Checkpoint Operations Guide. This document was approved by the
FAA. The edition of this guide in place on September 11, 2001, classified âbox cutters,â
for example as âRestrictedâ items that were not permitted in the passenger cabin of an
aircraft. The checkpoint supervisor was required to be notified if an item in this category
was encountered. Passengers would be given the option of having those items
transported as checked baggage. âMace,â âpepper spray,â as well as âtear gasâ were
categorized as hazardous materials and passengers could not take items in that category
on an airplane without the express permission of the airline.
On the other hand, pocket utility knives (less than 4 inch blade) were allowed. The
Checkpoint Operations Guide provided no further guidance on how to distinguish
between âbox cuttersâ and âpocket utility knives.â
One of the checkpoint supervisors working at Logan International Airport on September
11, 2001, recalled that as of that day, while box cutters were not permitted to pass
Staff Statement No. 3 9
through the checkpoint without the removal of the blade, any knife with a blade of less
than four inches was permitted to pass through security.
In practice, we believe the FAAâs approach of admonishing air carriers to use common
sense about what items should not be allowed on an aircraft, while also approving the air
carrierâs checkpoint operations guidelines that defined the industryâs âcommon sense,â in
practice, created an environment where both parties could deny responsibility for making
hard and most likely unpopular decisions.
What happened at the checkpoints? Of the checkpoints used to screen the passengers of
Flights 11, 77, 93 and 175 on 9/11, only Washington Dulles International Airport had
videotaping equipment in place. Therefore the most specific information that exists
about the processing of the 9/11 hijackers is information about American Airlines Flight
77, which crashed into the Pentagon. The staff has also reviewed testing results for all
the checkpoints in question, scores of interviews with checkpoint screeners and
supervisors who might have processed the hijackers, and FAA and FBI evaluations of the
available information. There is no reason to believe that the screening on 9/11 was
fundamentally different at any of the relevant airports.
Return again to the perspective of the enemy. The plan required all of the hijackers to
successfully board the assigned aircraft. If several of the ir number failed to board, the
operational plan might fall apart or their operational security might be breached. To have
this kind of confidence, they had to develop a plan they felt would work anywhere they
were screened, regardless of the quality of the screener. We believe they developed such
a plan and practiced it in the months before the attacks, including in test flights, to be sure
their tactics would work. In other words, we believe they did not count on a sloppy
screener. All 19 hijackers were able to pass successfully through checkpoint screening to
board their flights. They were 19 for 19. They counted on beating a weak system.
Turning to the specifics of Flight 77 checkpoint screening, at 7:18 a.m. Eastern Daylight
Time on the morning of September 11, 2001, Majed Moqed and Khalid al Mihdhar
entered one of the security screening checkpoints at Dulles International Airport. They
placed their carry-on bags on the x-ray machine belt and proceeded through the first
magnetometer. Both set off the alarm and were subsequently directed to a second
magnetometer. While al Mihdhar did not alarm the second magnetometer and was
permitted through the checkpoint, Moqed failed once more and was then subjected to a
personal screening with a metal detection hand wand. He passed this inspection and then
was permitted to pass through the checkpoint.
At 7:35 a.m. Hani Hanjour placed two carry-on bags on the x-ray belt in the Main
Terminal checkpoint, and proceeded, without alarm, through the magnetometer. He
picked up his carry-on bags and passed through the checkpoint. One minute later, Nawaf
and Salem al Hazmi entered the same checkpoint. Salem al Hazmi successfully cleared
the magnetometer and was permitted through the checkpoint. Nawaf al Hazmi set off the
alarms for both the first and second magnetometers and was then hand-wanded before
Staff Statement No. 3 10
being passed. In addition, his shoulder-strap carry-on bag was swiped by an explosive
trace detector and then passed.
Our best working hypothesis is that a number of the hijackers were carrying permissible
utility knives or pocket knives. One example of such a utility knife is this âLeathermanâ
item. We know that at least two knives like this were actually purchased by hijackers and
have not been found in the belongings the hijackers left behind. The staff will pass this
around. Please be careful. The blade is open. It locks into position. It is very sharp.
According to the guidelines on 9/11, if such a knife were discovered in the possession of
an individual who alarmed either the walk-through metal detector or the hand wand, the
item would be returned to the owner and permitted to be carried on the aircraft.
http://www.9-11commission.gov/staff_statements/staff_statement_3.pdf