Caradoc

"The purpose of a system is what it does."

The backscatter and MMW scanners don't detect explosives - as clearly stated by the people who invented the damned things.

Based solely on observation of the TSA's activities over the years, one might as well surmise that their purpose is not explosives interdiction, but drug interdiction. And they fail at that all too often too because their employees are so willing to accept bribes. Cheap ones, too.

Pesky Monkey

They have no ability to detect explosives. Their x-rays can't tell a book from c-4. If something has scary looking wires they call the bomb squad.

WillCAD

Well, sure, the AIT can't detect explosives per se, but it's stated purpose, when it was initially deployed, was to look for explosives concealed beneath clothing a la the Underwear Bomber. It was the panic caused by the Underwear Bomber that gave AIT supporters the justification to spend $1.2 billion over 3 years to buy all of those infernal machines and peek beneath the clothing of hundreds of millions of innocent people.

It was only later, after they were deployed, that their obvious flaws became, well, obvious to the flying public. But by then, some of them were already deployed, and logic and reason did not dissuade TSA from their planned course of making us all "safe" by looking at naked pictures of us and irradiating some of us.

LarryJ

The AIT scanners purpose is to find non-metallic items which are concealed in, or under, a passengers clothes--something that the WTMD can not do. They'll also find metallic items as well. The threat of explosives, which would pass through the WTMD without any chance of detection, is what led to the adoption of the AIT scanners.

Not sure which "x-rays" you're talking about.

The x-ray scanners used for carry-on bags were quickly upgraded, after the TSA took over, with the ability to show the difference between organic and inorganic material to give the operator more information. The scanner doesn't "detect" anything, it produces an image that the operator views to determine if the bag needs to be physically searched.

The CTX scanners that check checked luggage can clear the majority of bags without any human intervention. Some bags can't be cleared automatically and are diverted for a physical search and/or ETD scan. The purpose of the CTX screening is to prevent explosives from being shipped in checked baggage.

Caradoc

See the "pancake" argument for non-metallic, and Jonathan Corbett's demonstrations for metallic.

Next?

LarryJ

What's your point? The reason for the AIT scanners is clearly for explosive detection, something that the WTMD can not do. No technology is, or will ever be, perfect.

Wally Bird

The point is that explosives detection was the justification or rationale* for whole-body scanners. Which is not the same thing as a reason (as in reasonable). They do not detect explosives either.

*Leaving aside kickbacks, bungs or other financial shenanigans.

mulieri

Actually, the WTMD does a much better job of detecting conventional explosives than AIT...and a much better job of detecting firearms, and other weapons.

...But the WTMD isn't very good at detecting your little bag of pot. So props to the AIT for finding pot! Otherwise, some stoned dude might get on the plane and eat a bag of Cheetos next to you.

Caradoc

As stated - "the purpose of a system is what it does." The AIT scanners do not detect explosives, therefore that is not their purpose.

medic51vrf

Although that specific hole was closed, there are still others out there. I won't go into details in a public forum for obvious reasons but I can tell you that it would be VERY easy for me to get a firearm into the sterile area at a small commercial airport (with some minor assistance from some non-aviation people) and, once there, get it onto a commercial jet, to a larger airport, onto a larger plane, etc.

Yes, I think I'm smarter than the average bear and I KNOW I have more experience and training in these things than the average bear but then again there are people out there who know more than I do and have a vested interest in doing bad things so I'm sure there are others who could, and WOULD do what I know CAN be done.

LarryJ

Since the dictionary uses "reason" as a synonym for "rationale" I'm having a hard time understanding the distinction you're trying to draw.

ra·tion·ale/ˌraSHəˈnal/
Noun: A set of reasons or a logical basis for a course of action or a particular belief

The definitions of reason and reasonable are not related.

The AIT scanners can discover or identify the presence or existence of explosives which is the definition of "detect"

de·tect/diˈtekt/
Verb: Discover or identify the presence or existence of.

As a 22-year veteran of the airline industry I would question your definition of "easy". The dictionary says,
eas·y/ˈēzē/
Adjective: Achieved without great effort; presenting few difficulties.

While possible, it certainly would present more than a few difficulties. If your point is that the system is not perfect, then you're right. No system is. The airplanes, the mechanics that service them, and the pilots who fly them aren't perfect either but perfection is not possible and is not required to have a very safe system.

Himeno

Which the proponents of body scanners continually fail to achieve. Every stated rationale given for the scanners has been illogical and fail to stand up to any detailed scrutiny.

Body scanners do not detect explosives. They detect objects which reflect the EM radiation given off by the machine and are then visible - to either an operator or software - on a black and white image. They are more likely to detect sweat or buttons then any sort of weapon or explosive.

WillCAD

LarryJ, I think what Wally Bird meant when he said "rationale" was "stated reason", which is not always the same as the "actual reason." In other words, I think he meant that AIT was put into place for reasons other than those stated by TSA.

de·tect/diˈtekt/
Verb: Discover or identify the presence or existence of.

Nope, AIT cannot do that with explosives. Or pretty much anything else, either, at least not reliably or consistently.

There are two types of AIT - those with ATR and those without.

Those without ATR detect absolutely nothing - NOTHING. They merely create a digital image which is viewed by a human operator, and the human operator examines the image in an attempt to identify prohibited items on the image's subject. This is fraught with flaws, not the least of which being the fact that the operator might be asleep at the wheel, or might be a genuine perv who sends cutie pies or little children through the scan multiple times to get his jollies while ignoring his assigned task of looking for WEI. But be that as it may, non-ATR AIT doesn't actually "detect" a damn thing, any more than my phone's camera "detects" anything when I take a picture with it. It merely creates an image; any detection of anything is done with my own eyes, by examining the image.

AIT with ATR, on the other hand, doesn't create an image. Rather, it runs the scan returns through a software analysis, which is supposed to "detect" prohibited items by identifying "anomalies", i.e. "stuff which does not match the scan return properties of human skin." But this software, and the rationale behind it, is severely flawed.

You see, almost any object in the universe other than human skin fits the profile of "stuff which does not match the scan return properties of human skin," so the scan is basically looking for "the whole universe except human skin." But the whole universe does not consist of prohibited items, so even when the software identifies a scan return that doesn't match human skin, it hasn't really discovered or identified anything; it's up to the human operators to discover and identify the object which made the non-skin scan return - almost all of which are NOT prohibited items, such as folds of cloth, rolls of fat, or human sweat, which thus qualify as false alarms or false positives.

eas·y/ˈēzē/
Adjective: Achieved without great effort; presenting few difficulties.

Okay, how is this for easy - two guys get jobs, one at the Burger King in Concourse A-B at BWI, the other for the food service delivery company that supplies Burger King with its consumables. Delivery guy stops his truck at a truck stop or WalMart parking lot on the way to BWI and hides prohibited items inside the boxes of frozen burgers, trays of buns, or bags of Coke syrup. Burger King guy then retrieves the prohibited items when the supplies are delivered and hides them within the sterile area.

Bingo. Easy.

Wally Bird

I got into a bit of a semantic tangle trying to explain what I meant. I also assumed LarryJ was to some extent defending the deployment of body scanners, which may be incorrect.

Not being party to the evolution I don't know how it went, but I can imagine:
1. Chertoff being oversold (with or without financial encouragements) on the capabilities of the machines;
2. the TSA as a whole being oversold or bullied by Chertoff into accepting those capablilties;
3 the press and public (most of them) being duped into accepting them "To Keep Us Safe".

If the 'reason' behind body scanners is that they detect explosives, then that is patently incorrect since they don't. It is therefore unreasonable (or a better word if anyone has one) to accept and promote their use on that basis.

Don't know if that's any clearer.

And on the other point, there are many ways in which explosives could pass undetected through a checkpoint, but I'm not going to detail them. The TSA may not know or acknowledge this, but other agencies do.

LarryJ

My point has nothing at all to do with whether I think that the AIT scanners are effective.

My point was that the TSA's focus is, and has been, on the detection of explosives. Most of the changes that they have made over the past decade to both procedures and equipment are targeted at improving their ability to prevent explosives from passing through screening.

As far as the definition of "detect"... If you walk through a WTMD with a brick of C4 under your shirt the WTMD will not alarm. If took that same brick through an AIT scanner there's a very good chance that it would alarm. Some are saying that alarm doesn't count as "detecting the explosive" because the AIT scanner didn't label it an explosive. So what? The procedure that follows an AIT alarm will find the brick and the subsequent ETD test will determine that it is an explosive. The result is that the explosive is detected due to the AIT alarm.

Call that whatever you want but it's a lot simpler to say that the AIT can detect hidden explosives while the WTMD can not. If someone can't see the difference between those two screening results then maybe they're getting a bit too wrapped up with their animosity toward the TSA.