Here are some questions from commenter “Brian Turner” about the effect the pager and walkie-talkie explosions will have on flight security:

While I admire Israel’s audacity, it raises two questions:
1. When will TSA ban laptops, tablets and mobile phones from commercial flights? and
2. How long before our three-letter agencies use this tactic against the deplorables?

I’ve seen that sort of question all around the blogosphere, so although I’m no tech person, I thought I’d attempt an answer – particularly to the first question – and also throw open the topics to my intrepid readers.

First of all, you may or may not know that it’s already the case that cellphone batteries sometimes catch fire, on planes or otherwise. There are many stories of examples such as this:

When a battery is damaged, overheated, exposed to water, overcharged or has manufacturing defects, it can combust without warning. Either the smoke or fire can put passengers and crew on a flight in danger.

Signs that the battery is damaged include bulging or cracking, hissing, leaking, rising temperature and smoke.

The number of times lithium batteries on airplanes nationwide have overheated, smoked or exploded nearly doubled between 2020 and 2023, FAA data shows. The federal agency confirmed 77 such incidents in 2023, up from 39 in 2020.

In several incidents, the devices were put in a fireproof bag and the flight could continue.

Don’t we all need something new to worry about? These fires tend to be relatively easy to contain, however, and I don’t think there’s ever been a case of a cellphone battery fire bringing a plane down. Nor have their been any new regulations concerning these devices, as far as I know.

No matter what, I can’t imagine flights banning cellphones for the simple reason that most people these days wouldn’t be willing to travel without them. And even requiring them to be in checked luggage wouldn’t help that much if at all, because many people don’t check their luggage. And wouldn’t an explosion in the baggage hold would be especially dangerous, more difficult to detect and also more difficult to control? The surprising answer (surprising to me, anyway) to that question is “no,” because it turns out that cargo holds are designed to be so airtight that fires (smaller ones, anyway, as opposed to a huge explosion) would be likely to lack the oxygen to really get going, plus there are other protections:

A number of uncontrolled fires have occurred in cargo compartments, which contributed to an evolution of airworthiness regulations. The FAA’s ‘Lessons Learnt from Civil Aviation’ website identifies two tragic fatal accidents which were pivotal in driving this evolution.

In 1980 in Riyadh, shortly after take-off of a second generation wide-body aircraft, an uncontrollable fire occurred in the rear cargo hold. Tragically, all 301 passengers and crew died in the event. …

In 1996 in the Everglades near Miami, a second generation single-aisle aircraft experienced an uncontrolled fire in its forward cargo compartment shortly after takeoff, leading to the death of all 110 passengers and crew. …

The NTSB determined that just before takeoff, 144 expired chemical oxygen generators … had been placed in the cargo compartment in five boxes marked COMAT (company material) by ValuJet’s maintenance contractor SabreTech. This violated Federal Aviation Administration (FAA) regulations forbidding the transport of hazardous materials in passenger-aircraft cargo holds. Failure to cover the generators’ firing pins with the prescribed plastic caps made accidental activation much more likely. The investigation revealed that rather than covering the pins, maintenance personnel simply cut the cords attached to the pins or applied duct tape around the cans, and consumer-grade adhesive tape was also used to secure the ends. SabreTech employees indicated on the cargo manifest that the “oxy canisters”, which were loosely packed in boxes that were each sealed with tape and bubble wrap, were “empty.” ValuJet workers then loaded the boxes in the cargo hold in the mistaken belief that the devices were simply empty canisters that would be safe and legal to transport on a passenger aircraft. …

It was subsequent to the Everglades accident in 1996 that the limitations of the principle of relying purely on containment by oxygen starvation were acknowledged. …

… [In 1998) all new designs of aircraft, as well as existing aircraft in-service, were to be equipped … [with] fire detection system capable of alerting the flight crew within 1 minute of the fire starting became necessary, together with Halon gas fire suppression systems.

There’s a lot more information at that link for anyone interested, but the gist of the cargo hold situation today is that there are three levels of protection: airtight and fireproof cargo holds, cargo fire detection systems, and cargo fire suppression systems.

So, although the potential problem with phones or other devices could probably be handled by requiring them all to be stored in cargo holds, I still don’t think that will ever happen for the aformentioned reasons: all luggage would have to be checked (is there even room for that?), and passengers would be exceedingly angry.

And it’s not as though such devices are the only way explosives could enter a plane. If I’m not mistaken, the main reason for requiring that we remove shoes and only have little bottles in our carry-ons has to do with the possibility of explosives. What’s more, I’ve encountered plenty of airports where passengers have to walk past explosive-sniffing dogs; haven’t you? Here’s an informative article about those dogs; explosives are not the only thing they can detect, of course.

Lastly, it turns out the modern cellphones are not a particularly good receptacle for explosives compared to older devices:

University of Surrey’s Woodward, who regularly takes apart consumer devices, points out that within modern smartphones there is very limited space to insert anything extra, and the manufacturing process can involve robots precisely placing components on top of each other. X-rays show how tightly packed modern phones are.

“When you open up a smartphone, I think the only way to get any sort of meaningful amount of high explosive in there would be to do something like replace one of the components,” he says, such as modifying a battery to be half battery, half explosives. But “replacing a component in a smartphone would compromise its functionality,” he says, which could lead a user to investigate the malfunction.

In contrast, the model of pager linked to the explosions — a “rugged” device with 85 days of battery life — included multiple replaceable parts. Ang Cui, founder of the embedded device security firm Red Balloon Security, examined the schematics of the pager model apparently used in the attacks and told WIRED that there would be free space inside to plant explosives. The walkie-talkies that exploded, according to the manufacturer, were discontinued a decade ago. Woodward says that when opening up redesigned, current versions of older technologies, such as pagers, many internal electronic components have been “compressed” down as manufacturing methods and processor efficiency have improved.

… In countries like China, where many devices are manufactured, there is always the possibility of a domestic operation to plant backdoors, but such a scheme would need to be elaborate to skirt international scrutiny of the devices …

To find exploding cell phones, you have to go back to 20th century tech.

For all these reasons, I don’t think we’ll be losing our inflight cellphones any time soon. However, there’s that China thing …