Airlines ‘Battery Bomb’ dilemma

Posted on February 12, 2014


32,000 feet and levelling. A comforting thought for a 100% ground based species!

Having successfully survived the vulture like scrutiny of the power-hungry supervising the airport security gauntlet, mandatory to getting on any public flight, I find my thoughts drawn to the security charade we have to participate in. A process that exists almost exclusively as a social engineering exercise, a contrived sense of security, little more.

What an embugerance! Airport security is classed as one of the most stressful things we can subject ourselves to. As we know stress represents one of the more significant aging factors alongside its degradation of the immune system. Does this mean then the security measures imposed on the air travelling public, whilst protecting us from coming down to earth with a terminal bump, impose a slow death by stress inducement?

I digress …..

With every incompetent attempt by headline grabbing terrorists to smuggle some class of explosive device onto a plane our political elite feel obliged to impose another degree of control as we head for the clouds. To quote a few of the more headline grabbing scenarios:

  • The shoe bomber sees us now paddling sock footed through security.
  • Liquid bomber, a boon to the pharmaceutical industry fostering a niche market for 100ml or less packaged product.

and the list could go on.

What frustrates many is that these remediation actions are targeting the lowest threat common denominator and not the highest. The subsequent control impositions keeping themselves just the right side of the line of consumer revolt and commercial prerogative, whilst maintaining a protective air of political composure and responsiveness in the fight against terror. Call it the cynic in me but imagine IF mobile phones and other personal compute devices were found to be such a threat and banned!

I hear your chortle, patiently humouring me, how could any politician reflecting on his voting public consider such an imposition, political suicide. So how can this be postulated especially when the tide is moving in the opposite direction. We are witnessing the relaxation of usage restrictions on these very same devices? Largely by public demand, but perhaps we have all been looking in the wrong direction at the radio frequency risk to aircraft systems.

Imagine for a moment the inconvenience and turmoil a ban on any device that contains a lithium ion battery would impose on the travelling business community? I would not be typing this missive for example, or looking forward to some email catch up, or spreadsheet brain gym. I hate to think what the iPod/Smartphone headphone hissing, personal space invading hipsters, to whom the phrase ‘silence is golden’ is an alien concept would do with themselves! They would probably be thrown into a mental cold turkey as they struggle with the concept of original thought having to jack out of their normal self-imposed reality distortion audio-brain fog.

The quandary I have is with the double standards being applied to airline threat and risk analysis when you reflect on the real threat potency of lithium ion batteries or their ilk on-board planes.

Quote the Civil Aviation Authority (CAA), ‘The huge growth in people carrying lithium batteries on aircraft poses a growing fire risk’.

In their overwhelming majority these batteries are stable and reliable mini powerhouses, the beating hearts of our personal electronics. Stable and reliable when produced in accordance with high quality assurance and regulated manufacturing processes, common to the familiar household names in electronics. Worryingly though the risk profile starts to rise when considering the large unbranded aftermarket where quality is lower and the probability of higher volatility starts to raise its head with cheap production cutting corners. That is before you consider the reality of how simple it is to intentionally damaged or destabilise these units to induce what is known as ‘thermal runaway’.

‘Thermal Runaway’ is a chemical process where a battery generates heat, causing additional reactions that generate more heat, and so on until the entire thing finally erupts in flame or explodes if contained in a confined space (case of a mobile phone, computer or other hard case). AH but batteries have circuitry to prevent this I hear you sagely interject. Well yes, but it is this very circuitry that can so easily be compromised through accidental damage, poor manufacturing process or tampering.

The recent research into the risk of this class of aftermarket devices points to a worrying thought that planes are flying with this class of potentially explosive device scattered throughout their fuselage. It is estimated that the planes will have between 300 and 700 such devices, depending on size, even without mal-intent in the equation it is perhaps only a matter of time before we have a serious incident.

The unbranded ‘clone’ batteries are attractive because they are cheap, even a terrorist has to work to a budget! Furthermore they often use lower quality circuitry, in itself more prone to failure. But more importantly they can be readily acquired by unqualified back shop technician, who breach vendor warranties to replace batteries that are not meant to be end user serviced. These cheap and cheerful practices introduce a completely invisible risk dimension. It is almost impossible outside of dedicated vendor exclusive diagnostic tools to identify devices that have been compromised in this way. The airport scanners are blind men with white sticks as they allow these bombs free passage. This is just Joe Public, before you bring into the mix your terrorist of choice.

Now throw into the mix the wilful destabilization of these battery cells, again undetectable by our airport scanners. The chance factor of an explosion or fire are almost guaranteed with the assistance of some modest heating agent, even a few judiciously applied hand warmers could be enough to tip a compromised battery cell into a volatile state.

If you’re wanting visual evidence then head over to ‘Exploding Laptop’ video produced by PC Pitstop and D2 Worldwide.

Some key findings:

  • Lithium Ion batteries do not need external oxygen to combust, they have all they need built-in to keep burning.
  • Attempts to extinguish with water simply exacerbates and scatters the fire, it’s a metal, electrical chemical fire and can escalate explosive reactions.
  • Requires a Class D extinguisher.
  • Batteries can be projected up to 10m during combustion.

I don’t have any easy answer. The post office in the US and UK now restricts such loose batteries, batteries not sealed in a device, but the embedded nature of a battery is a false security filter. Just because a battery is embedded in a device does not make it secure. This rule actually implies that these embedded batteries are safer than loose ones, when in fact they are probably contained in a more explosive package. A loose battery pack may burst into flame, or expand and smoulder profusely, given space to expand it will cause a hostile chemical, metal file resulting in localised thermal damage. However I would postulate the encased batteries are a significantly higher risk prone to a pressure confinement Thermal Runaway inducing explosion. Imagine bits of your nice shiny Apple Mac’s magnesium casing flying around a pressurised aircraft cabin? The chemical, metal fumes from a battery fire are poisons enough in such a finally balanced air environment. An air quality environment which in most planes is already lower than would normally be experienced on the ground.

If a terrorist is prepared to modify the heal of a shoe I have no doubt they can stretch to unscrewing a PC casing to destabilise batteries. With a bit more creativity they could readily encase that in a flammable ignition source to kick off and accelerate thermal runaway, possible something as simple as a hand warmer. The imagination does not have to be very creative to see how simple this would be and completely bypassing any current airline security checks.

I have no doubt preventative action to ban such devices will never be championed by a politician, it is a guaranteed vote loser. I only hope they will not be given grounds to rue turning a blind eye at the memorial of a plane full of someone’s family and friends. Lockerbie may not have been this postulated type of disaster, but the end result would be frighteningly similar.

Measures that could be considered include:

  1. All such devices to be transported in hold luggage only. At least in the hold they will be in-flight at a considerably lower temperature thus reducing the thermal runaway potential. BUT this does scupper business travellers hand luggage only expedience.
  2. Removable batteries, batteries go in the hold and PC can still operate via inflight seat power cables. It has a long wait time form airlines to provision such facilities sin ALL seats, BUT this offers a premium price/extra option for airlines so does have some incentive. Not to mention the BOON in hardware refresh this would have for manufacturers, if all notebooks and smartphones had to have removable batteries. This would be a win/win for users of smartphones that struggle to give more than 5 hours’ worth of juice (iPhone), at least you would have the convenience of a second battery to swap out.
  3. Mandatory vendor battery paring circuitry that prevents aftermarket batteries being fitted to devices. This would have to disable devices if unidentified battery packs where detected. Dell are one manufacturer who has this in some of their machines already but it allows a user F1 key over-ride.
  4. Mandatory thermal temperature sensors and alarms (using notebook / smartphone speakers) and damage/ tamper detection circuitry. Not preventative, but it gives a warning if a battery pack goes out with safe temperature limits and maybe wins a few minutes of grace to remediate.

As for this frequent flyer I have been dreading the day when inflight phone calls would become legal, personally I don’t see the urgency in short haul flights, and most long haul have phones in the seats anyway so if it’s that urgent use those! Perhaps there is hope, a ban would give weary travellers the perfect excuse to just kick back and jack out of the world at large for a few hours. Airlines could become a rare sanctuary space, what a different outlook that gives.

For now, we wait….