Tape Shows 9/11 Hijackers Passing Through Security

July 22, 2004 -- An airport surveillance tape obtained by ABC News shows the five hijackers of American Airlines Flight 77 easily passing through security at Dulles International Airport outside Washington, D.C., in the hour before the flight took off on the morning of Sept. 11, 2001.

Flight 77, one of four planes hijacked by al Qaeda terrorists that day, would slam into the Pentagon later that morning — about half an hour after the second plane hit the World Trade Center in New York.

All 64 people on board Flight 77 and another 125 at the Pentagon were killed.

The surveillance tape shows the first two of the five hijackers — Majed Moqed and Khalid Almihdhar — as they enter one of the security screening areas, place their carry-on bags on the X-ray machine belt and proceed through the first metal detector.

Both men set off the alarm and are subsequently directed to a seconddetector.

Almihdhar does not set off the second detector and ispermitted to go through the checkpoint, but Moqed fails once more and is then subjected to apersonal screening with a metal detection hand wand. He appears to pass the inspection and is allowed to pass through the checkpoint.

About 17 minutes later, Hani Hanjour — who is believed to have been piloting the plane in its final moments — places two carry-on bags on the X-ray belt at the checkpoint, and proceeds, without setting off the alarm, through the detector. Hepicks up his carry-on bags and passes through the screening area.

One minute later, as seen on tape, Nawaf and Salem Alhazmi enter the same checkpoint. Salem Alhazmi successfully clears the detector and is permitted through the checkpoint.

Nawaf Alhazmi sets off the alarms for both the first and second detectors and is then screened with a hand wand before being cleared.

A Significant Error

It was a significant error, according to Billy Vincent, former head of security for the Federal Aviation Administration.

"The hijacker is cleared, and the final two make their way to the gate," Vincent said.