Clive Robinson • December 30, 2010 12:55 AM

I’m not surprised it’s come around as will most things about “carry on” untill the fundemental problem is solved.

Although “carry on” is not the fundemental problem it is the major issue currently and it’s a problem without a solution because…

Let’s be honest quite a few of us can think of ways of getting even quite large sharp edged objects that can be used as weapons onto planes.

Likewise many of us can think up ways of getting “largish” volumes of liquids or solids onto a plane as well.

And will be able to as long as passengers are alowed “carry on”.

Being able to think how to use objects in surprising ways tends to be one of the side effects of an inquiring mind musing “what if”.

Put simply it’s a problem that cannot be solved as our entire modern technology based society is built by people with inquiring minds musing “what if”.

Importantly though is Joe Sixpack does not want to give up his SUV, mobile phone or other trapings of his modern materialistic life and return to subsistance farming etc. So inquiring minds musing “what if” are here to stay as is passenger “carry on”.

As Bruce and many others have pointed out the easy and effective answers to airplane security (cockpit doors etc) have been taken, but these can only go so far.

The most sensible next move in airplane security is to remove the pilots etc. Yes it’s controversial but it has in many ways been done already.

If we had fully automated planes “box cutters” or other sharp edged weapons would not be an issue because computers cann’t be coerced by them in the way humans can. Further cockpit doors would not need strengthaning as cockpits would not have humans on the other side.

Further if we had fully automated planes their design would change quite quickly putting the flight systems well out of reach of even quite large amounts of explosive. Not because of security concernces but simple economics, the design of aircraft with cockpits is very inefficient.

But for goodness sake don’t let Joe Sixpack know… he’s seen to many episodes of “Terminator” spin offs, and he knows that someday he is going to have to pay for his modern lifestyle. The problem with this is he thinks “payback” is when the machines fight back or just simply go wrong.

He does not tend to realise the reality of his technological existance and the real “payback” is his body failing due to a cholesterol soaked or other poison ingested lifestyle. Thus he gives no sign of knowing that infact his chance of living much beyond forty is based on his access to technology…

[For those who think I’m a “bit off my trolley” see the leading causes of death in the US and at what ages and compare it to those of nonindustrialised low technology parts of the world.]

The simple fact is Joe Sixpack’s musings are generaly based on what he saw on the “idiot box” in the last week or so. And much of that is based on either what is newsworthy or entertainment.

Newsworthy is generaly only about very very rare events, and entertainment is usually based on the extream “what if” musings of inquiring minds…

Thus Joe Sixpack “knows” what is going to happen when the machines “fail” or “rise up”, not the reality of how in the everyday world they work reliably and support his continued existance.

However the problem the TSA have is not people with inquiring minds nor for that matter is it the people who wish to kill themselves for whatever reason. The problem the TSA has is “public image” or what Joe Sixpack thinks from what he “knows”…

After a few seconds thought you will realise that the TSA have been setup to be the fall guy for the politicians should another terrorist incident on a plane leaving US soil occur. That is the politico’s have done their bit by putting a line of defence between themselves and the difficult task of solving the problem and have thus “been seen to act” at a time of National crissis.

The real reason aircraft are vulnerable to terrorism is the use of humans to control them and where these humans are situated (up on the nose not down in the belly).

The TSA cann’t fix this problem and the politico’s won’t because there is no advantage in it for them.

So all the TSA can do is tinker at the edges and this is what this is. As long as we have persuadable / irrational / eratic / failing humans at the controls in easily accessable places aircraft security is going to be compromised in a way that cannot be solved.

One of the things the TSA have probably considered but not talked about is “det cord” it looks a lot like “washing line” and is what SWAT and other anti hostage forces use to open very substantial (much more so than upgraded reinforced cockpit) doors.

In the hands of somebody who has done some training det cord can go from concealed to deployed in less time than it would take Joe Sixpack to think “what’s he doing” and lumber out of his seat… This probably goes for the most attentive of air marshals as well, thus if deployed successfully we would be back to pre 9/11 security levels on aircraft.

The solution is not to play around tinkering at the edges but remove the problem but as this is not acceptable to Joe Sixpack who “knows” this dancing around the problem will continue.

Clive Robinson • December 30, 2010 4:26 PM

@ Brandioch Conner,

“Focus on detecting the explosives”

If only it was as easy as that.

As you are aware explosives come in many forms some quite easy to detect quickly and simply. And some are so difficult there would need to be a truck load sitting on the detector for half an hour or more…

The use of sniffer dogs has been sugested but they appear when all the costs are factord to be very expensive, short lived and limited in what they can detect. Also they are not an easily scaleable resource.

Various things have been tried including the “puffer” but don’t appear to work well outside of the carefully controled environment of a lab.

Then there is the rather akward issue of “dual use chemicals”. Nitrates for instance are used in explosives, cured meat and medications and some everyday objects are made from nitrated celulose such as knife handles and coated papers such as playing cards. They also occur quite naturaly as part of the decay process of household waste (Amonium Nitrate crystals where originaly collected from “middens”).

Likewise various chlorates.

Explosives come in a variety of densities many in similar density as plastics or other materials used in cloathing, luggage, cosmetics and many other common items you might expect people to carry

Their EM spectrums vary considerably as well.

Thus all in all I can understand why the TSA does hand searches of items looking for cavities that might be used to put explosives in because it is probably easier to detect the place of concealment than it is the explosives.

That being said as I have mentioned inquiring minds are going to be more able to disguise explosives than even highly trained staff are going to find.

And if the TSA do get to the point they can act as a reliable deterrent (ie they consistantly get more than 50% of all blind tests) the terrorists will simply change their tacticts to evade what is effectivly a static checkpoint…

One solution is to ban all “carry on” however this is not practical as some travelers have medical needs such as 02 cylinders, CPAP machines etc.

Also as has been seen in the past “Commercial interest” wins out (think laptop bans).

Hence my recent comments about removing the vulnerability of aircraft currently accessible to passengers (ie the pilots).

Clive Robinson • December 31, 2010 2:43 AM

@ Wendy,

One of the lesser known interesting things about cryptography is the eclectic tastes in music you discover by accident about those who work in the field and just how many are also performers.

David Khan made a note towards it in his book many years ago when talking about what makes a cryptographic practitioner.

And I must admit at this time of year as we get towards 12th night I wish we still had the tradition of wassailing as I’m quite fond of figgy pudding and mulled cider over and above the community singing 😉

Clive Robinson • December 31, 2010 5:46 PM

@ cm,

“Clive – never thought this about you previously but you’re behind the times”

It had to happen sometime 🙁

But before somebody shout’s “quick get the cat the old parrot’s fallen of his perch” have a few minutes contemplation with your favourate brew.

I will start by saying there is actually a bit more behind getting rid of the pilot than another 9/11 type attack via the cockpit door.

However I’m sorry but it has to be said, the use of an airplane crashing into a US city is way to strong an idea for terrorists to not want to do. The only thing better would be to get hold of a nuke (buy a Russian or steal a US one) and detonate it in Washington or New York, this appears to has been OBL’s primary aim for some time prior to 9/11 as a way to deal with the US.

That is OBL had been activly investigating various forms of weapons of mass destruction and he was smart enough to realise that chemical and biological weapons where not realy viable due to delivery system issues.

So this only left energy weapons, bullets, bombs, missiles and nukes. The first two of which are fairly standard terrorist fare and don’t realy get you very far. The last being nukes OBL was activly trying to get hold of but the US had done a reasonable job of buying up ex soviet state stocks. Generaly we consider missiles to be a product of nation states due to the R&D costs involved.

However we know that there had been some sort of technology transfer on missiles and nukes between Pakistan and North Korea, and that many senior figures in Pakistan where keen on transfering the technology on to anyone who would attack the US & Israel or other perceived enemies of the Muslim world. Thus AQ Khan via his “Khan Laboratories” running out of Switzerland started selling nuclear and related systems technology to Iran, Libya and other “axis of evil” and undesirable nations that are believed to have sponsored terrorism.

However North Korea’s missile tech that is up for sale appears to have a range of less than 1000Km which is not sufficient for OBL tucked away in Afghanistan. Nor was it particularly accurate so could not be used to deploy conventional explosives against US targets that would have been in range.

With hindsight it is easy to see the similarities between the kinetic energy of a fully laden wide body aircraft and a cruise missile with a 1000Kg high explosive war head. And that you can get pilots to fly aircraft into enemy targets (Japanese WWII). And some authors (Tom Clancy) had joined the dots together so it is unknown as to if it was an original idea to AQ or if they had read it in a novel.

Now whilst I would agree with you that a 9/11 style attack is unlikley to succeed, however what is to stop the terrorists actually getting jobs as pilots?

Or as more recently shown putting a bomb on via UPS / TNT / whoever?

The simple fact is that the weak link in aircraft is the pilot and the systems that enable him to control the aircraft. Be it mechanical linkage or fly by wire these systems unfortunatly go down the length of the aircraft and are vulnerable to quite small amounts of explosive in the right place and finding the places is not that difficult.

If however you think about the likes of drone aircraft their control systems are usually sited within the main body close to the root of the wings, which is one of the strongest parts of the aircraft.

Contrary to what a lot of people think pilotless aircraft are a reality as far as the technology is concerned and it does not require the likes of GPS accurate to a few centimeters which would be “weapons grade technology”.

More uptodate versions of fairly old ILS designs will actually do the job. That is the aircraft flies down a flight path designated by a series of transmitters at known positions on the ground transmitting the equivalent of ranging codes the solution of which would give the aircrafts position with respect to the transmitters to within a few cm’s and is within the capability of many physics and other engineering graduates using comercialy available parts.

As for the danger of spoofing and jamming there are ways to deal with these problems that use a mixture of technologies from various fields of endevor including cryptography.

This leaves the question of “what happens when the system goes wrong” the argument is that a “human in charge” would be able to take over and land the aircraft safely…

Well this argument is not as good these days as it has been in the past for a number of reasons.

Firstly the computer hardware technology itself is now more reliable than the airframe.

Secondly the information the pilot gets from the “instruments” is not independent these days it goes into digital displays which are controled by computers little different to those that would be used for the flight control systems. Further the instruments output is often signal processed prior to being displayed.

Thirdly and more importantly is the human mind under stress any better than the knowledged based software?

The jury is still out on this but lets just say that pilots are not as good as they once where and have considerably less experiance due to the increased reliability of the aircraft…

We have talked of “zero flight hour pilots” for some years now, that is we train pilots on simulators and throw all sorts of problems at them to make and keep them “flight worthy”.

The problem is as any combat experianced soldier can tell you training is not real life, and when the adrenaline hits you don’t know what’s going to happen.

There is also the issue of what do you train for and why… and the answer is one Bruce talks about when he points out the TSA is set “to fight the last battle”. That is the training is by and large based on past incidents and a limited set of “what ifs” (which for many determanistic systems is fine but not those of a more complex nature).

Now for the interesting bit to think about, the software used to run the simulator is essentialy a computer model of the aircraft with semi-realistic instrument data as the input.

When the instructor want’s to simulate a fault it is this instrument data that gets changed then feed into the simulator model that then changes the displays and physical actuators that feed sensory information into the pilot.

The pilots job is to take this sensory input and then react in a way to act as feedback to return the simulator model back to a stable state.

Now the simulators model is actually a lot more complicated than the actual flight systems and generating the required stability model to replace the pilot is actually a less complicated issue as has been known for around half a century.

When you look at high performance military fighter aircraft the pilot does not actually fly the aircraft. The aircraft are so unstable that the flight systems need to implement the stability model and adjust the various flight surfacces hundreds if not thousands of times a second.

Now the question you should ask is what advantages are to be gained from such unstable aircraft. Well in the military aircraft it is manoeuverability and rapid response. However you can also get improved flight efficiency that means significant savings for airline operators.

For many reasons the future of direct “hands on” pilots is over and once the legal and social issues with Frankenstien’s Monster are laid to rest so will comercial airline pilots.

If for no other reason than machines are more reliable and actually safer than humans as has been shown with computer driven research cars and various public transport systems (some of which where designed over thirty years ago).