threat of a bomb in a fake tablet

[NoHeat]

According to the Guardian, it was the risk of a bomb disguised as an iPad that prompted the recent bans of electronic devices larger than a smartphone, on US-bound flights from several countries.

Here's the Guardian story, which is being widely cited by other outlets:

https://www.theguardian.com/world/2017/mar/26/plot-explosives-ipad-us-uk-laptop-ban

Questions remain about why the UK implemented a smaller ban than the US, and why other western countries banned nothing at all, according to the story.

 

[SkyDog58]

Each country is responsible for its own security and is free to act as it best sees fit. No mystery.

 

[deonb]

Wonder what the interior volume is of an iPad compared to the interior volume of a Nokia 2110.

Must have set those terrorist plans back by minutes.

 

[Scrabo]

More security theatre.

A bomb in a fake iPad placed in the aircraft hold is still as dangerous as one in the cabin.

 

[WannFly]

More security theatre.

A bomb in a fake iPad placed in the aircraft hold is still as dangerous as one in the cabin.

Exactly. I have been wondering how the bomb blast will be safe in the hold of the airplane for some time now

Sent from my SM-G935V using Tapatalk

 

[Sluggo63]

More security theatre.

A bomb in a fake iPad placed in the aircraft hold is still as dangerous as one in the cabin.

Exactly. I have been wondering how the bomb blast will be safe in the hold of the airplane for some time now

Sent from my SM-G935V using Tapatalk

Can't find the article right now, but I read somewhere that hold luggage gets screened differently/better than carry-ons. For carry-ons the scanners are optimized for guns/knives/etc., where in the hold luggage screening area they have more effective explosive detection devices/bomb dogs/residue sniffers, etc. Explosives have a better chance of being detected in hold screening than passenger screening.

 

[PeterNSteinmetz]

I am wondering what the odds are of a bomb the size of an iPad going off in either the cabin or cargo hold actually seriously endangering a flight are? Obviously, not a good thing, but what are the chances of seriously endangering the passengers or crew?

 

[NoHeat]

I am wondering what the odds are of a bomb the size of an iPad going off in either the cabin or cargo hold actually seriously endangering a flight are? Obviously, not a good thing, but what are the chances of seriously endangering the passengers or crew?

A 9.7" iPad weighs about 15 oz. The larger model weighs more.

Here's a story about Pan Am 103, which blew up over Lockerbie, Scotland, in 1988

the FBI determined the plane was brought down by 12 to 14 ounces of explosive.

The explosive was packed in a cassette player about 25 inches from the fuselage skin of the Boeing 747, according to the British Air Accidents Investigation Branch's report about the crash. The explosion punched a hole in the fuselage at 31,000 feet and the plane tore apart at 500 mph, raining down debris for 80 miles, the report said.
“Thus, there is little doubt that separation of the forward fuselage was complete within 2 to 3 seconds of the explosion,” the report said.

 

[deonb]

For carry-ons the scanners are optimized for guns/knives/etc., where in the hold luggage screening area they have more effective explosive detection devices/bomb dogs/residue sniffers, etc.

So go scan it downstairs and hand it back to me in the cabin? Can even charge me $15 to go do that - revenue opportunity.

Emirates have already made accommodations to allow the devices at the airport and only take them prior to boarding. They'd just on any kind of opportunity to give users back their devices - no matter how painful for them.

But then this really had to be about security in the first place... which it isn't.

 

[PeterNSteinmetz]

Interesting. I wonder if that was just an unlucky case, or to be expected as the usual outcome.

For example, see the report in this article which recalls several incidents of bomb explosions with less disastrous consequences:
http://bigstory.ap.org/urn:publicid:ap.org:a81d5e017f0345e7898f67003c45bc3d

Of course any explosion is a very bad thing, but the cost benefit analysis of banning all tablets should certainly be different if there is a 99% chance of disaster versus a 1% chance.

 

[NoHeat]

Interesting. I wonder if that was just an unlucky case, or to be expected as the usual outcome.

Pan Am 103? Same as you, I don't know whether the in-flight breakup was just unlucky.

More recently, there was the ISIS claim that they used a 12-ounce soda can to house a bomb that took down a Russian Metrojet flight over Egypt. I don't know whether that design has been confirmed.

http://www.cbsnews.com/news/did-isis-use-soda-can-bomb-to-bring-down-russian-plane/

 

[Scrabo]

A 9.7" iPad weighs about 15 oz. The larger model weighs more.

Here's a story about Pan Am 103, which blew up over Lockerbie, Scotland, in 1988

the FBI determined the plane was brought down by 12 to 14 ounces of explosive.

The explosive was packed in a cassette player about 25 inches from the fuselage skin of the Boeing 747, according to the British Air Accidents Investigation Branch's report about the crash. The explosion punched a hole in the fuselage at 31,000 feet and the plane tore apart at 500 mph, raining down debris for 80 miles, the report said.
“Thus, there is little doubt that separation of the forward fuselage was complete within 2 to 3 seconds of the explosion,” the report said.

They used odorless Semtex on that and Although the explosion was in the aircraft hold, the effect was magnified by the large difference in pressure between the aircraft's interior and exterior.

 

[Kritchlow]

More security theatre.

A bomb in a fake iPad placed in the aircraft hold is still as dangerous as one in the cabin.

Ahhh... all security is just theatre..??

 

[PeterNSteinmetz]

Ahhh... all security is just theatre..??

Unfortunately most airline security is ineffective at improving traveler safety because the odds of a terrorist attack on an airline are just so extremely low.

Many estimates suggest that if you are serious about wanting to save lives with public safety spending there are likely 100X more effective ways to spend the money than mass screening of passengers.

Remember - you are twice as likely to be struck and killed by lightning than to be killed in a terrorist attack on an airplane.

 

[comanchepilot]

One can probably fit a pound or so of C4 into a ipad = remove enough battery so it just turns on and stays on for 10 min or so in case security wants to check it - then has enough charge to set off the plastique - and 16oz of C4 will bring down an airplane at altitude - if you detonate it at 35k - in the middle of the Atlantic or mid way over the pacific - you will not have fuel at 10,000' to get anywhere - having the airplane ditch is just as effective.

 

[Sluggo63]

Unfortunately most airline security is ineffective at improving traveler safety because the odds of a terrorist attack on an airline are just so extremely low.

Are they? And why is that?

What if there was no airline security? No bag checks. No x-ray screening. You show up to the airport, your bags go in the belly without being checked, and you walk aboard without any x-ray to your carry on, and no wanding/x-ray to your person.

What would be the odds of a terrorist attack on an airline then?

 

[PeterNSteinmetz]

What would be the odds of a terrorist attack on an airline then?

That's a very good question. From all appearances the rate didn't change much after the institution of stricter policies in 2001. There have only been very few cases where airliners leaving a US airport have been destroyed by a non-crew member. If memory serves, prior to the September 2001 attacks, there was one in 1986, one in 1964, and another in 1962. So it was an extremely rare occurrence even before the TSA.

If you compute the rate of such attacks prior to Sept 2001 and after, there is no statistical evidence that the rate has changed. Given the very low rate of such attacks, it is hard to accumulate enough data to find such an effect. Arguing that TSA interventions have prevented attacks is sort of like arguing that because I ate cereal for breakfast yesterday, my house was not struck by a meteor. Both things are true, but as people often say, correlation does not imply causality.

From a policy perspective I think the question has to be asked then, without clear evidence that the policy of mass screening of innocent passengers works, is this -- Is the $8.1 billion cost of the TSA, the costs in invasion of privacy and hassle from performing 660 million searches per year, and the indirect deaths on the highways when people divert from short haul flights to driving (which is 167X more dangerous than commercial flying) worth the likely nearly negligible reduction in risk of such attacks?

 

[PeterNSteinmetz]

Another interesting historical point related to this issue. It was legal to carry firearms on airplanes until 1962. In the late 60s there was a strong increase in the number of hijackings, which peaked in 1969. The federal law requiring metal detectors for screening passengers was not implemented until 1972, after hijackings had already started to decrease.

What I wonder about is this -- did banning firearms on planes embolden the hijackers and make planes more attractive targets because the hijackers knew they wouldn't be confronted by an armed passenger?

 

[Art VanDelay]

As previously stated luggage going into the baggage compartment receives more thorough examination. Additionally it's packed into ld3 cargo containers with lots of other bags enveloping and surrounding them. Third some (not all) airlines now have this type of liner in place inside their ld3 cans ;

 

[Sluggo63]

That's a very good question. From all appearances the rate didn't change much after the institution of stricter policies in 2001. There have only been very few cases where airliners leaving a US airport have been destroyed by a non-crew member. If memory serves, prior to the September 2001 attacks, there was one in 1986, one in 1964, and another in 1962. So it was an extremely rare occurrence even before the TSA.

If you compute the rate of such attacks prior to Sept 2001 and after, there is no statistical evidence that the rate has changed. Given the very low rate of such attacks, it is hard to accumulate enough data to find such an effect. Arguing that TSA interventions have prevented attacks is sort of like arguing that because I ate cereal for breakfast yesterday, my house was not struck by a meteor. Both things are true, but as people often say, correlation does not imply causality.

From a policy perspective I think the question has to be asked then, without clear evidence that the policy of mass screening of innocent passengers works, is this -- Is the $8.1 billion cost of the TSA, the costs in invasion of privacy and hassle from performing 660 million searches per year, and the indirect deaths on the highways when people divert from short haul flights to driving (which is 167X more dangerous than commercial flying) worth the likely nearly negligible reduction in risk of such attacks?

I get all that. But you have to concede that there was a tremendous paradigm shift when it comes to airline hijacking on 9/11.

 

[PeterNSteinmetz]

I get all that. But you have to concede that there was a tremendous paradigm shift when it comes to airline hijacking on 9/11.

That's true. But at the same time, the type of attack used on September 11, 2001 stopped working 53 minutes after it was introduced, when the passengers of Flight 93 decided to fight back. Probably the thing which has helped the most since then is simply a change in policy, namely, don't cooperate with hijackers and fight back if needed.

One of the things which concerns me the most about the present approach of mass screenings is that it appears that the hassles of modern commercial air travel cause people to skip short haul flights and drive instead. It is estimated that about 500 people per year are killed on the highways each year because of this and the TSA's intrusive policies. If true, that means that in 16 years since 2001, about 8000 excess people have died because of the TSA's policies; that's roughly twice the number which died on September 11, 2001. And if so, we did that to ourselves with an over-reaction to a very rare type of attack.

 

[EppyGA]

The 9/11 terrorists used razor knives that were 100% legal on 9/11

 

[Sluggo63]

That's true. But at the same time, the type of attack used on September 11, 2001 stopped working 53 minutes after it was introduced, when the passengers of Flight 93 decided to fight back. Probably the thing which has helped the most since then is simply a change in policy, namely, don't cooperate with hijackers and fight back if needed.

Right. So with post-9/11 hardened cockpit doors and a flight full of fighting passengers that type of attack won't happen anymore. So the bad guys adapt. That's the issue. Security is almost always reactionary. September 11 happens, IRCDs and FFDOs. So the terrorists try shoe-bombing. Now we take our shoes off. Then the underwear guy... we get millimeter wave scanners. A threat pops up, it gets thwarted (or succeeds) and we try to design something to keep it from happening again. Definitely not a perfect system, but it's what we got.

But then, when we get some intelligence about a possible weakness (explosives in tablets, laptops, etc.) and we react to that to try and stop it, everyone gets in a tizzy about our 'freedoms'.

I am definitely not a TSA apologist. I think they are about the most worthless agency out there (just watch the latest video that's gone viral over the past few days of a TSA agent "patting down" a young man to see what I'm talking about). But, I do believe that our intel people in this country are trying to keep us safe by being proactive when they get a lead and reactive when someone gets caught. Sometimes it works. You may remember the printer toner bomb plot that was foiled several years ago, maybe not since it dealt mostly with cargo carriers and it was stopped before it happened. That whole thing was stopped because the Saudi intel community got a hold of some information and gave it to the US intel folks. (Cargo Planes Bomb Plot)

The reason we don't see more 9/11 type attacks is not because that has a low probability of happening, it's because the bad-guys know that that won't work anymore because of what we said above. But I guarantee if we announced that we as a country were going back to pre-9/11 screening procedures; IRCDs were coming off the airplanes and the flimsy plywood doors were going back on; box cutters would be allowed again on flights, what do you think the bad guys would do?

One of the things which concerns me the most about the present approach of mass screenings is that it appears that the hassles of modern commercial air travel cause people to skip short haul flights and drive instead. It is estimated that about 500 people per year are killed on the highways each year because of this and the TSA's intrusive policies. If true, that means that in 16 years since 2001, about 8000 excess people have died because of the TSA's policies; that's roughly twice the number which died on September 11, 2001. And if so, we did that to ourselves with an over-reaction to a very rare type of attack.

No, it actually means that 8,000 people didn't know how to do a proper risk assessment. IF one of these people HAD to fly somewhere, let's say to London, and I gave them a choice of carrier. Carrier A you can board with no hassle, no screening, just get on board and jet off to jolly ole' England. Carrier B... you're going to be hassled a bit. You'll have to take your shoes off and put your laptop on a conveyor belt. It'll add an hour of inconvenience to the travel. Which would you pick? How about if I told you that if you flew Carrier A you had a 167x more likely chance of crashing in a fiery ball of aluminum in the middle of the Atlantic than if you flew on Carrier B? Is the 150%+ chance of dying worth the hassle?

 

[PeterNSteinmetz]

It'll add an hour of inconvenience to the travel. Which would you pick? How about if I told you that if you flew Carrier A you had a 167x more likely chance of crashing in a fiery ball of aluminum in the middle of the Atlantic than if you flew on Carrier B? Is the 150%+ chance of dying worth the hassle?

But is there any good evidence that those are the kinds of odds we are trading against? Is there some reason to think the odds are that high? The rate of attacks did not demonstrably decrease when the TSA put restrictions in place and we really don't know. I suppose most of us would choose the hassle if it truly was a 167X increase in substantial odds of being blown up, but there is no credible evidence that is what we are talking about. Yes, the TSA and about 1/2 of the american people seem to subjectively think that the odds are just terrible, but there is no credible evidence to support that. I'm a scientist, just show me the data.

But let's say it was a 10 fold increase, just for the sake of argument. I think it might be reasonable for someone to decide they prefer the lack of hassle and a 1 in 2 million years of life chance of being blown up to having the hassle and a 1 in 20 million years of life chance. (That is actually how low the odds are.) The odds of being struck by lightning are about 1 in 1 million years of life and people just don't really worry about that. It is rational to not worry about such rare events when there are much more important risks to worry about and try to mitigate.

Now let's say the odds were a 167 fold increase. That would mean that by traveling hassle free one would be taking a roughly 8.4 per hundred thousand years of life chance of being blown up. Even that is not too bad. Most people who are risk takers, say GA pilots or rock climbers, are willing to take a 1 in 10,000 (10 per 100,000) chance of death just for the thrill of it. Amongst rock climbers I generally found that it was only when the odds got up to around 1 in 1000 that most would start to think more seriously about it.

In terms of freedom, shouldn't people be able to make their own choices in life so long as they don't forcibly endanger others? People might want to fly GA aircraft for example, or eat fatty hamburgers, or avoid broccoli. These are all risky things, in terms of life expectancy, which reasonable people might choose to do, given their values in life.

My primary objection is that with the federal government and the TSA enforcing these rules, no one has any choice. Why not let the airlines, their insurance companies, and the passengers make these kind of choices in a market driven process? (http://realairlinesecurity.org has a bigger discussion of that idea.)

I think the data is mushy enough here that there is no very clear one size fits all answer to the question of the proper tradeoff between security and convenience in commercial airline travel. Is there any inherent reason it has to be the same for all carriers and all passengers?

But, I do believe that our intel people in this country are trying to keep us safe by being proactive when they get a lead and reactive when someone gets caught. Sometimes it works. You may remember the printer toner bomb plot that was foiled several years ago, maybe not since it dealt mostly with cargo carriers and it was stopped before it happened. That whole thing was stopped because the Saudi intel community got a hold of some information and gave it to the US intel folks. (Cargo Planes Bomb Plot)

I agree, this type of police work actually stands a chance of working. Isn't this where we should be spending our security money? Not on very low yield interventions like mass screening of innocent passengers which have negative side-effects. Resources are finite and when we spend $8.1 billion each year on mass screening that is less money to spend on intel gathering and other police work.

No, it actually means that 8,000 people didn't know how to do a proper risk assessment.

That's true, people are very bad at properly assessing the risks of very rare events. But our current TSA policies encourage people to think air travel is much more dangerous than it actually is and make poor choices. Why not allow there to be choice in the marketplace? I suspect the airlines and their insurance companies can figure this out a lot better than bureaucrats who will always err on the side of caution, almost no matter what the cost.

 

[Sluggo63]

But is there any good evidence that those are the kinds of odds we are trading against? Is there some reason to think the odds are that high? The rate of attacks did not demonstrably decrease when the TSA put restrictions in place and we really don't know. I suppose most of us would choose the hassle if it truly was a 167X increase in substantial odds of being blown up, but there is no credible evidence that is what we are talking about. Yes, the TSA and about 1/2 of the american people seem to subjectively think that the odds are just terrible, but there is no credible evidence to support that. I'm a scientist, just show me the data.

I don't know, Peter... I was just using the number that you threw out there. 167x.

Is the $8.1 billion cost of the TSA, the costs in invasion of privacy and hassle from performing 660 million searches per year, and the indirect deaths on the highways when people divert from short haul flights to driving (which is 167X more dangerous than commercial flying) worth the likely nearly negligible reduction in risk of such attacks?

 

[PeterNSteinmetz]

But I guarantee if we announced that we as a country were going back to pre-9/11 screening procedures; IRCDs were coming off the airplanes and the flimsy plywood doors were going back on; box cutters would be allowed again on flights, what do you think the bad guys would do?

Interesting to think about. I suspect that if they tried that type of attack everyone in the plane would attack them, knowing they have nothing to lose. Worst case scenario they would kill the planeload of passengers, probably more likely they would be subdued and/or killed with some injuries or deaths amongst passengers and crew. Almost certainly the terrorists would not be able to use the planes as guided missiles.

 

[PeterNSteinmetz]

I don't know, Peter... I was just using the number that you threw out there. 167x.

Maybe that wasn't clear. That is the ratio of risk of driving on a trip of a given number of miles versus flying it commercially. I don't think that is the increased likelihood of a terrorist attack if we went back to pre-9/11 security measures.

 

[Sluggo63]

Maybe that wasn't clear. That is the ratio of risk of driving on a trip of a given number of miles versus flying it commercially. I don't think that is the increased likelihood of a terrorist attack if we went back to pre-9/11 security measures.

No. I understood completely. I was trying to make an analogy that if people are going to use a transportation mode (whether it's driving or taking "Airline A") that is 167x more likely in them dying rather than put up with an hour (tops) of hassle from the TSA, then they are making a poor risk analysis. I'll take the hassle of the airport rather than drive myself cross-country on the highway.

When my daughter was going to college in PA and would drive to IN to see her boyfriend, it would scare me to death until I knew she was safely there. If she flew, I really didn't worry about a thing.

 

[Kritchlow]

Unfortunately most airline security is ineffective at improving traveler safety because the odds of a terrorist attack on an airline are just so extremely low.

Many estimates suggest that if you are serious about wanting to save lives with public safety spending there are likely 100X more effective ways to spend the money than mass screening of passengers.

Remember - you are twice as likely to be struck and killed by lightning than to be killed in a terrorist attack on an airplane.

I just disagree, especially on your last point.
Even though those statistics are true, the reason for it contradicts your prior speech about airline security being useless.

 

[PeterNSteinmetz]

I just disagree, especially on your last point.
Even though those statistics are true, the reason for it contradicts your prior speech about airline security being useless.

Can't say I understand the reasoning there - care to clarify - perhaps what "it" refers to or with an example?

I wouldn't say "useless" or literally zero utility. Even placing a single security guard at one checkpoint must have some, perhaps very tiny, effect on safety. More precisely I would say the level of utility of mass screening does not justify the costs - money, time, invasion of privacy, loss of lives pursuing alternate means of transportation.

 

[Kritchlow]

Can't say I understand the reasoning there - care to clarify - perhaps what "it" refers to or with an example?

I wouldn't say "useless" or literally zero utility. Even placing a single security guard at one checkpoint must have some, perhaps very tiny, effect on safety. More precisely I would say the level of utility of mass screening does not justify the costs - money, time, invasion of privacy, loss of lives pursuing alternate means of transportation.

One reason you are twice as likely to get hit by lightning twice vs once in an airplane terror attack, is because the TSA dies have a deterrent affect. So, you can't have it both ways saying TSA doesn't work, yet terrorism is unlikely.

I've asked this before on these forums....
Would you feel safer with security as is, or pay $10 less for a ticket and have ZERO security. Nothing. No metal detectors, TSA agents, nothing. Just walk freely around the ramp after getting out of your car. When you're ready just climb the stairs to board your airplane.

 

[Art VanDelay]

Didn't anyone watch my video ? Why we even still having this discussion ?

 

[Kritchlow]

Didn't anyone watch my video ? Why we even still having this discussion ?

On my way.... guess I missed it in the shuffle.

 

[PeterNSteinmetz]

One reason you are twice as likely to get hit by lightning twice vs once in an airplane terror attack, is because the TSA dies have a deterrent affect. So, you can't have it both ways saying TSA doesn't work, yet terrorism is unlikely.

As noted in my posts above, I'm not aware of any data showing that the TSA has a deterrent effect. The rate of terrorist attacks did not demonstrably decrease after the TSA was implemented.

It is rather easy to imagine ways to implement terrorist attacks even with TSA policies in place (even when one is not too serious about it), so no reason to think on a causal basis that TSA mass screenings work.

Finally, they catch only 4% of banned items with these mass screenings, so no reason to think that will deter serious terrorists.

It is quite logically possible for there to be a extremely low rate of such attacks AND for the TSA to be doing their screenings AND for there to be no causal relationship between these two facts.

But I'm a scientist, so if these is some other data demonstrating the effectiveness of TSA mass screenings, I'd love to see it.
Please post.

 

[PeterNSteinmetz]

I've asked this before on these forums....
Would you feel safer with security as is, or pay $10 less for a ticket and have ZERO security. Nothing. No metal detectors, TSA agents, nothing. Just walk freely around the ramp after getting out of your car. When you're ready just climb the stairs to board your airplane.

I suspect in the long run, in a free market choice situation, many people would choose something close to the latter. Why not let the market decide instead of having the TSA forcing choices on everyone?

It doesn't have to be all or nothing and different airlines in different situations with their passenger bases can make different choices. That is really a false dichotomy put forward there.

It would likely take a while for the situation to evolve. Initially I suspect airlines would eliminate the 3 oz liquid rule and the removal of belts and shoes. Experts like Bruce Schneier suggest an initial return to something like pre-9/11 rules, so still a magnetometer.

 

[Kritchlow]

As noted in my posts above, I'm not aware of any data showing that the TSA has a deterrent effect. The rate of terrorist attacks did not demonstrably decrease after the TSA was implemented.

It is rather easy to imagine ways to implement terrorist attacks even with TSA policies in place (even when one is not too serious about it), so no reason to think on a causal basis that TSA mass screenings work.

Finally, they catch only 4% of banned items with these mass screenings, so no reason to think that will deter serious terrorists.

It is quite logically possible for there to be a extremely low rate of such attacks AND for the TSA to be doing their screenings AND for there to be no causal relationship between these two facts.

But I'm a scientist, so if these is some other data demonstrating the effectiveness of TSA mass screenings, I'd love to see it.
Please post.

How many successful commercial aircraft terrorist attacks has there been involving US carriers since 9/11?
Not scientific, but I think the common sense test shows the TSA is a deterrent.
I do not believe it's coincidence.

Again, I ask the question:
Would you rather pay $10 less for your ticket and have absolutely zero security?

 

[Kritchlow]

I suspect in the long run, in a free market choice situation, many people would choose something close to the latter. Why not let the market decide instead of having the TSA forcing choices on everyone.

Okay.... I was typing while you were.
It would be impossible to mix the two scenarios to see which would win in a free market.
One way alone is needed, and I do not believe the public would stand for zero security. Remember way back when security was lax or non existent... the hijackings.

 

[PeterNSteinmetz]

How many successful commercial aircraft terrorist attacks has there been involving US carriers since 9/11?
Not scientific, but I think the common sense test shows the TSA is a deterrent.
I do not believe it's coincidence.

While it is perhaps counter-intuitive, you can statistically show that it very well could be a coincidence.

If memory serves, the last time airplanes leaving US airports were destroyed by a non-crew member prior to 2001 were in 1986, 1964 and 1962 (or very close to those years, I'm not in front of the computer right now). That's a very low rate of occurrence and it is therefore fairly probable that 16 years have elapsed since 2001 with no such attacks, purely by chance.

If you like we can walk through the calculations together here. Sometimes our intuitions about these things or "commonsense" are not very accurate, especially with very improbable events.

 

[PeterNSteinmetz]

It would be impossible to mix the two scenarios to see which would win in a free market.

Why ? It seems perfectly feasible for different airlines to implement separate policies, possibly on a concourse or gate basis.

 

[Kritchlow]

While it is perhaps counter-intuitive, you can statistically show that it very well could be a coincidence.

If memory serves, the last time airplanes leaving US airports were destroyed by a non-crew member prior to 2001 were in 1986, 1964 and 1962 (or very close to those years, I'm not in front of the computer right now). That's a very low rate of occurrence and it is therefore fairly probable that 16 years have elapsed since 2001 with no such attacks, purely by chance.

If you like we can walk through the calculations together here. Sometimes our intuitions about these things or "commonsense" are not very accurate, especially with very improbable events.

But I don't think you can compare terrorism in 1964 to 2017.