NEW SCANNERS REFINE AIRPORT LUGGAGE EXAMS

* Two devices that employ CAT-scan technology will make it easier to
check for explosives and narcotics in bags headed for cargo storage

Advice to Portland air travelers: Don't try to check through that
suitcase if you've packed explosives, dope or unprocessed film.

Portland International Airport is installing a pair of $1 million
mechanical detectives that use the technology from medical CAT scans
to look for contraband in luggage headed for aircraft cargo storage.

With a tightly focused but stronger X-ray than is used for purses and
carry-on bags, the equipment looks at several slices of an item rather
than taking an overall look. Its computer sounds the alert if it
senses articles of densities matching more than 100 different
explosives. It also can be programmed to look for narcotics.

Each machine can check more than 300 bags per hour.

"These things can look inside luggage just like a medical CAT scan
looks inside patients," said Mitch Barker, regional spokesman for the
Federal Aviation Administration in Renton, Wash.

Portland is in the second wave of U.S. cities to receive InVision
Technologies' CTX scanners, which have been purchased by the FAA. The
equipment, developed with federal research funding, evolved after the
1988 downing of a Pan Am jet in Scotland. In that case, the explosive
apparently was packed inside a portable radio that was in the plane's
cargo area.

The FAA has bought about 150 of the scanners, and several European
airports have installed the same equipment.

Of course, explosives and drugs have been no-nos for a long time, but
the advice about unprocessed film comes directly from InVision
Technologies, which says the best strategy is to have the film in
carry-on bags. A further safeguard is to ask that security screeners
hand-check the film.

The first of Portland's CTX 5500 scanners is located near the Alaska
Airlines ticket area, where it can be used to inspect luggage from
curbside check-ins or bags from the regular ticket counter.

Global Security Co. is training its personnel and after another week
or two, attention will be shifted to the second machine in the United
Airlines ticket area. It, too, will be installed between the curb and
ticket counters.

Each scanner is about the size of a large van and weighs nearly 5
tons. Barker said 96 scanners were operating at the start of this
year, including about 20 dual X-ray machines checking cargoes.

The Portland scanners use a highly directed X-ray, according to
InVision Technologies spokesman Bob Madden. "It is not like the
'scatter' X-ray used on carry-on. It takes a few slicelike pictures of
the bag and contents," looking for more than 100 types of explosives,
he said. If the material looks suspicious to the computer, an operator
at a double-screen console is alerted to call for a manual inspection.

And to keep operators alert, the machine occasionally tosses in a fake
object to see if it gets spotted.

Madden said the X-ray is so tightly focused that it would have to hit
a canister of raw film before any damage is done. That damage,
according to a warning issued six years ago by European photo
organizations, would look like a thin white line on prints made from
the film and a faint line of fogging on slide film. Developed film is
in no danger.

InVision said the FAA requires stronger radiation for bags headed to a
cargo hold, and the impact on film could be cumulative if the traveler
checks in the bag several times.

The system is considered safe for magnetic tapes and computer
disks.

Doug Roberts, spokesman for the Port of Portland, said the FAA might
add a third scanner later.

Barker said he cannot comment on future placement plans or on how the
units will be used. "Passengers should remember that everything they
take onto an airplane is subject to security checks," he said.

The general practice is to assign a scanner to the busiest airline at
a terminal, according to Barker. In Portland's case, because United
and Alaska airlines are busy but at opposite ends of the terminal, the
program begins with two scanners.

You can reach Bill Stewart at 503-294-7670 or by e-mail at
billstewart@news.oregonian.com