Altimeter Watches Now a Terrorism Threat

This story is so idiotic that I have trouble believing it’s true. According to MSNBC:

An advisory issued Monday by the Department of Homeland Security and the FBI urges the Transportation Security Administration to have airport screeners keep an eye out for wristwatches containing cigarette lighters or altimeters.

The notice says “recent intelligence suggests al-Qaida has expressed interest in obtaining wristwatches with a hidden butane-lighter function and Casio watches with an altimeter function. Casio watches have been extensively used by al-Qaida and associated organizations as timers for improvised explosive devices. The Casio brand is likely chosen due to its worldwide availability and inexpensive price.”

Clocks and watches definitely make good device timers for remotely triggered bombs. In this scenario, the person carrying the watch is an innocent. (Otherwise he wouldn’t need a remote triggering device; he could set the bomb off himself.) This implies that the bomb is stuffed inside the functional watch. But if you assume a bomb as small as the non-functioning space in a wristwatch can blow up an airplane, you’ve got problems far bigger than one particular brand of wristwatch. This story simply makes no sense.

And, like most of the random “alerts” from the DHS, it’s not based on any real facts:

The advisory notes that there is no specific information indicating any terrorist plans to use the devices, but it urges screeners to watch for them.

I wish the DHS were half as good at keeping people safe as they are at scaring people. (I’ve written more about that here.)

Posted on January 5, 2005 at 12:34 PM28 Comments


Armin January 5, 2005 12:47 PM

So all hikers with multifunction watches will now be questioned about their watch and their intentions?

Mine also has a compass built in (apart from the barometer, altimeter, timer, etc. pp), couldn’t this be used as well? Once the plane flies in a certain direction, then…

Francois Kashy January 5, 2005 1:13 PM

Here’s an idea. Buy as many altimeter watches as you can. Give them out to everyone going into or out of the airport. Or just leave them laying around.

rcme January 5, 2005 1:42 PM

I am not sure I get the danger of an altimeter watch worn by a passenger on a commercial aircraft. It seems to me that since the passenger, and the altimeter watch, are going to be in a pressurized cabin, the altimeter watch isn’t going to provide any meaningful data about actual altitude to the passenger wearing the watch. Perhaps if the passenger were in an unpressurized cargo hold with their altimeter watch… but then TSA wouldn’t be inspecting them anyway.

vortex January 5, 2005 1:45 PM

Perhaps it means watches in luggage, not on a person…seems like that would be more of a threat, as they could be strapped onto something in the bag.

jgh January 5, 2005 2:02 PM

Pressurized cabins don’t maintain sea-level pressure, but about 8000 ft. It’s a balance between comfort and the strength required to support the pressure differential.

Fazal Majid January 5, 2005 2:07 PM

Wasn’t the Lockerbie bomb triggered by an altimeter? I once read El Al depressurizes baggage containers prior to loading them just to catch altimeter-driven bombs.

Joe Huffman January 5, 2005 2:45 PM

I interpreted the Casio watch warning to mean possession of multiple watches. Someone wearing a Rolex and a dozen Casio’s in his briefcase needs to explain some things. I have enough experience with the media to believe something got lost in the translation and that DHS wasn’t that stupid in this case.

Fuzzy January 5, 2005 3:24 PM

According to a WABC-TV story
“According to U.S. intelligence sources, Al Qaeda is trying to obtain watches with a hidden butane lighter and watches with an altimeter built in, that together would be used to bring down commercial airliners.”

According to an MSNBC story
“There is currently no law against carrying an altimeter or a lighter onto an airplane. The items cannot be confiscated, but one official said Monday that if the watches are spotted, screeners likely would engage in further checking of the passenger.”

Yes, the Lockerbie flight (Pan Am Flight 103) bomb was triggered by an altimeter device.

Waldo Nell January 6, 2005 12:48 AM

It reminds me when Czech airlines stopped me from carrying my pocket knife onto the airplane – its blade was barely 2″ long. However, in South Africa after you pass customs and security, you can purchase an assegaai at duty free! For those who do not know what that is – it is quite similar to a spear. So how about contradiction!

J. Alex Urbanowicz January 6, 2005 4:37 AM


You can cut someone’s throat (or threat to do so) with a very small (but sharp) knife, but using assegai in hand to hand combat in cofnined space of the passenger airplane would be very problematic if not impossible.

Mike Gray January 6, 2005 7:47 AM

I have never understood the confiscation of pocket knives and nail clippers. If they are worried about a 2″ knife, then they should be confiscating all belts too, right? A belt buckle could be just as dangerous as the nail clippers. Also, the belt could be used to strangle someone. Then what, they make you remove all of your clothes because if you were to remove them during the flight and twist them up you could form something like a belt which could be used to strangle someone? None of this really makes any sense. I believe that is Mr. Schneier’s point.

Roy Owens January 6, 2005 8:06 AM

The story makes sense in a sense. When newspapers have nothing newsworthy they must come up with something to fill the spaces between ads. The paper can always redo a story on that idiot that tries putting pants on horses. When Heimatsicherheit – Homeland Security – has nothing new, they cannot publish blank pages, they cannot issue blank alerts. So they have to get inventive. The giggle factor does not matter if these people have no shame.

Marcos January 6, 2005 9:35 AM

I think Wi-fi and Bluetooth pocket pc’s are a much greater threat then wristwatches with a hidden butane-lighter function and watches with an altimeter function.

Dylan January 6, 2005 10:51 PM

The Pants on Horses thing (The Society For Indecency To Naked Animals) was a hoax invented by Alan Abel. Even the name of the society was a joke. Unfortunately, some people took it seriously and…

Andy January 7, 2005 3:42 AM

As Armin says, that’s every keen hiker victimised then.

And my watch tells reads the temperature – what about detonating if it gets cold enough. Or even the revolutionary idea of a detonator based on time? I mean, a long haul flight is a big window. So we can have watches if they don’t tell us barometric pressure, temperature, direction, time, or any other useful feature.


j7915 January 7, 2005 11:56 AM

The Israelis use a pressure chamber for luggage to activate a trigger that uses the pressurization cycle of a flight to trigger a bomb, not the absolute aircraft flight level.

The Lockerbie bomb was alledgedly loaded in Cairo? So the trigger, like in a sea mine, was cycled and armed after one takeoff and landing.

On an other note, commercial passenger planes all have pressurized cargo, if the cabin itself is pressurized. There maybe an exception here or there, so please post.

GMoney January 7, 2005 5:07 PM

So tell me where I can get one of these cheap altimeter watch? Last time I looked they were not CASIO cheap but what do I know, Al-Qaida has the almighty Bin Laden backing right?! Watch out Rolex owners you’re next !!!

trent January 8, 2005 2:01 AM

To clarify Bruce’s blog entry: The explosives wouldn’t be in the watch. The watch would be used as the trigger for a luggage bomb. It is a modern version of a very old improvised exlosive technique.

Shad January 8, 2005 3:44 AM

Take a sealed bag of potato chips in cabin. Watch it inflate like a balloon as the plane ascends. (The same in smaller scale is valid for the little cups of coffee cream, watch the foil on their top bulge out.) It is firm enough to press on a microswitch. Who needs watches?

(If we consider the security alerts as a form of immunity reaction, some of the phenomenons we are witnessing these days are not dissimilar to autoimmune diseases, with all their slowly crippling effects.)

Bruce Schneier January 8, 2005 7:33 PM

There is a difference between searching for remote triggering mechanisms in checked baggage, and stopping people who are wearing a certain kind of watch as they walk through a security checkpoint. The first makes sense; the second is idiotic.

Carl January 10, 2005 8:11 AM

I flew into and out of the Munich Airport after the Lockerbie incident. I had two Swiss Army knives on my person on my way out. (large ones with saw, awl, etc…) The Munich passenger screeners looked at both and allowed me to keep them. They were more interested in my walking stick (disguised firearm?) than anything else I was going to carry on…

I agree that an altimeter that is carried into the passenger cabin has a very low security risk. Maybe if it is one that has a strap for hanging around the neck, that could be used as a garrote…

Rob January 10, 2005 11:20 AM

My wife and I flew from London a year ago and had nail scissors taken out of our baggage. On our return flight from Glasgow another pair of nail scissors, which we hadn’t realised we’d packed, was also confiscated from the same bag. The checkers in London had found one pair and, satisfied, forgotten about the second. So if you want to get a knife on a plane, pack two. Or just buy a bottle of beer in the departure lounge and then smash it, bar-fight-style, to make a very effective glass dagger.

Geoff January 11, 2005 3:53 PM

Three days ago I flew American Airlines transatlantic, and they displayed altitude information on a continuously updated basis both on the cabin screens (some of the time) and on the personalized TV screens at each seat (at least in Business Class). Besides, you can estimate altitude just by looking out the window. Even if a watch was set to do something at some altitude it would need a radio transmitter to reach the hidden bomb in the luggage, so the whole alert seems like more silliness.

Jimbob September 27, 2006 1:40 PM

This entire thread is exactly why professionals worry about security and idiots right un-informed blogs without doing due diligence. Research Pan Am 103.

Osiris November 15, 2006 11:27 AM

Well you could just break off the blade part of the assegaai and a leave a short part for the handle.

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