With the war in Iraq and the threat by the latter country and its allies to take the battle through terrorism into the countries of the coalition forces, airline and aircraft safety has once again become an issue.
Major airlines, especially those flying to or from North America have already reported significant drops in passenger loading and even SAA has cancelled some of its flights to New York. The decrease in travellers may be because passengers fear further attacks on aircraft and in particular the use of explosive devices as another 11 September type attack is now not going to be easy with a commandeered commercial aircraft being likely to be disabled or downed by air force aircraft.
In the United States there is a strong drive to have explosive detection systems installed at all airports. The typical system uses core technology similar to that used in X-ray CAT scanning. Larger systems can screen up to 550 bags per hour (lower capacity versions are available for smaller airports) and the video screen images highlight explosives and bomb components, while an alarm situation is automatically displayed. The trained operator then carefully views the screen image to see if the threat is real and if so follows established protocols for threat resolution (sometimes trace detectors as described below are used for final confirmation). The installation of these explosive detection systems was spurred by the downing of Pan Am Flight 103 and received a further boost following the 1996 crash of TWA 800. The original plan of Congress was to have these systems installed in all airports by 2014 but 11 September saw a revision of this plan to 31 December 2002, an impossibility! The plan was later revised to one which would see 1100 bulk scanners (as described above) installed by the deadline and to complement these with up to 6000 trace detection instruments. 100% screening by bulk systems is now targeted for 2009.
Trace detection equipment
Trace detection equipment works in a completely different way and most instruments make use of a technology called Ion Mobility Spectroscopy (IMS). Here a wipe is taken of a suspicious object and the sample is heated to expel the explosive substances. These are ionised (charged) and the time of drift in an electrical field allows accurate and rapid identification of the substance. Most trace detectors will display to the operator the actual type of explosive, be it RDX, TNT, Semtex, nitro-glycerine or whatever. Trace detectors are remarkably sensitive to small traces of explosive and explosive residue is like a fingerprint on a window, hard to completely remove. In fact people who have handled explosives will still have detectable traces on their hands a week later, despite thorough washing.
A personal experience here is worth relating. Some years ago my company demonstrated an IMS-based narcotics detector in the customs area of Johannesburg International. One night we had a flight in from Nairobi and a certain lady was stopped by the customs official. A wipe on the outside of her luggage provided a clear indication of cocaine. This was confirmed with a second wipe whereupon the customs officer invited her into a search room where she was requested to open the case. A wipe from the inside of the case sent the monitor to its end stop with a massive cocaine signal. The customs officer had tried to engage the lady in conversation as to what was in her case but she refused to speak. Eventually he started his own search and immediately found a large brown envelope. Inside were more US 100 dollar bills than I have ever seen in my life. A further search revealed no cocaine (it was the notes that were contaminated) and the lady in question was released, as it is not an offence to import large amounts of foreign currency. I am, however, sure that her name and details were added to the list of travellers to monitor. Another indication of sensitivity was where we were asked to demonstrate an explosives detection device at the Infantry School in Oudtshoorn. The object was an old polished and cleaned 155 mm shell which was used as an ornament. Despite the fact that this had been fired years before, both RDX and TNT were easily detected.
Coming back to the use of trace detectors at airports the US intends to use them to screen hand luggage or the contents thereof. How many times have you seen a camera being passed over the counter as its owner does not want the film to be subject to the X-ray machine? How many times has the search official asked you to switch on your calculator to see that it actually works? With both of these devices it would be possible to pack enough explosive in to seriously damage an aircraft if detonated in the correct location. Trace detection will pick up any indication of explosives and covers the carry on baggage problem.
In the interim, US airports intend to use trace detection on hold baggage where bulk screening equipment is not installed in the facility. The procedure to be used (so as to avoid massive boarding delays) is called the '40-40-20' principle. Under this system 40% of bags will just be wiped on the outside, 40% will be opened and also wiped on the inside, and 20% will be subject to a more thorough search where all objects over a certain size, such as toiletries will be wiped. Some experts believe that this procedure is unreliable, but my own experience with this equipment, where we were able to tell from low level alarms for cocaine that a flight had arrived from Rio, gives me confidence that it will work. Again for the potential bomber we now have a major deterrent in place and you can be sure that the more suspicious looking passengers will be given a thorough going over. Remember that airports prefer bulk detectors to the trace systems because they can process hundreds of bags an hour, instead of just 20 or 30. So it is not the technology, but the need to process passengers rapidly. In fact during the Olympics, Salt Lake City International Airport used trace detection. They did not use 40-40-20 but wiped the outside of each bag and the hands of the passenger as he stood in the queue at check-in, resulting in no additional delay.
Trace detection technology is itself still developing and at least one company now offers a booth into which the passenger steps and within seconds he is screened for the detection of explosives or narcotics. The technology also continues to evolve as it is still the only practical method (in sniffing mode) of detecting and identifying the even more horrific chemical warfare agents such as Vx, Sarin and mustard gas. Unfortunately you still need a fully equipped laboratory to determine whether the white powder is the real thing or just sugar, milk powder or talcum powder.
When it comes to Europe, some countries like France and Italy are using the CAT-scan type equipment from the USA while other airports like Heathrow and Frankfurt (both of which had to react rapidly after the Pan Am disaster) use more conventional X-ray equipment. According to some experts these X-ray systems do not meet American standards, although when a high capacity machine finds a suspicious bag it is transferred to a machine that does meet FAA standards, minimising the 'false positive' alarm problem. While the number of suspicious objects or real bombs detected is not made public, flights out of Frankfurt or Heathrow have not yet had another Pan Am incident, although of course there have been bogus false alarm calls.
Hi-Tech Security Solutions has, on several occasions, tried to interview personnel from ACSA on the security systems installed at our airports, with little avail. This is despite the fact that the most effective security is to provide knowledge of deterrents. It is believed that X-ray equipment, probably similar to that used at London Heathrow and Frankfurt has been installed at Johannesburg International but whether that is being used for 100% screening of baggage is unknown. This would appear unlikely as a physical hold luggage search, similar but less exhaustive than those used for years by El Al, is still being carried out on US bound flights of SAA. However, the latter may just be an additional deterrent measure.
Regarding SAA flights to North America and London Heathrow, these appear to follow the US-demanded protocol of locked cockpit door and plastic cutlery. On recent flights to other European destinations with the local airline the cockpit door has been open during the flight and proper knives and forks are certainly provided in Business/First Class. At least one of the security loopholes has been closed by SAA. It always concerned me as a flyer when International flights originating in Durban and Cape Town operated internally as domestic services. If I was a would-be bomber and was not brave enough to sacrifice myself in the deed, I would have travelled to Johannesburg domestically, placing my device in the toilets at the rear of the aircraft with the usual pressure device as used on Pan Am.
For those who still have to fly, it is a lot safer than driving on our roads. Despite all the hype surrounding bombs on aircraft, most crashes are due to pilot error or mechanical failure. The only verified crashes due to a bomb on board are Pan Am 103 in 1988 and the Air India incident over the Atlantic during 1985. We may never know the real reason for the Helderberg crash but TWA 800 was brought down by ignition in the central fuel tank, not a bomb as originally thought.
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