Reuters: Expansion of ban on larger electronics on airlines likely: U.S. Since this blog is about foreign affairs, I’m skipping the latest brouhaha. Let’s go straight to the threat. All issues deserve political attention. But eventually, the debate about  laptop bombs should move to the technical, because that is where the solution lies.

CNN opinonator Bruce Schneier doesn’t like this. He doesn’t like being inconvenienced. The 865 words of a previous opinion piece  by Juliette Kayyem make no mention of the technical issues. Both pieces misidentify bombs on aircraft as a political problem, or something they are resistant to, because they are not naturally technical people.

These articles follow the trend in our society to politicize technical problems. It is understandable that global warming has been politicized, because it impacts all mankind. But the laptop ban penalizes the elite for the few hours of their lives that they’re actually flying.

A counterargument  lies  in the fact that the laptops in checked baggage are hazardous even if they don’t contain bombs. The hold of an airliner does have a fire suppression system, but those in use are considered inadequate to extinguish a lithium battery fire. To do so, a large source of inert gas would have to be carried. SkyBrary states that even for a single exploding aerosol can,

The FAA has developed minimum performance standards for these systems and it has been demonstrated that although water misting alone is unable to pass the exploding aerosol can fire test, a combination of water misting and inert gas (nitrogen) discharge may be more effective. However, for such a solution to be viable, a means of on-board nitrogen generation will be needed.

A lithium battery is much more difficult to extinguish. Onboard nitrogen generators are not currently deployed. Two cargo jets have already been lost to lithium fires.

Moving the laptops, and other large electronic devices to the hold is a reactive, not proactive, response. The valid reason is that bomb makers are not thought to have developed the means to remotely detonate a bomb in the hold. But do they need to?

The original chemical timer, the “time pencil”, was developed during World War II. Once activated, a corrosive acid dissolves a wire holding a mechanical detonator under spring force. These are still used today, but would be difficult to conceal. But electronic alternatives exist, as we have seen with the ubiquitous use of cellphones as detonators of IEDs. Timers are actually quite simple.

The ban is the best possible reactive response.  A good hacker would have no trouble devising a way to detonate an electronic device in the cargo hold. We have been saved so far by the self selection process by which a person becomes a terrorist. It tends to exclude that kind of talent. But not absolutely. At an unpredictable moment in the future, the threat may encompass electronic bombs that do not require manual detonation by a terrorist.

The ban may fail to provide protection, unannounced, at some unpredictable time in the future. There is no timeline.

Why are electronic devices a particular hazard? Not because they are electronic, but because they are made of combinations of metal and plastic, and contain voids, empty space, and near-voids, solids, liquids and gels; parts of low density, like batteries – and maybe, bombs. To understand why this is a problem, we’ll next consider how  the two types of airport scanners work.

To be continued shortly — with a solution.