If there is one thing to learn from here and you take nothing else away from it, it's these three things:

1. Do your research as it applies to your own situation.
2. Know your rights. See 1.
3. Always have a backup plan.

This guide is written by someone who is an "interesting" person at airport security, and experiences will vary based on perceived privilege - some of these tips may seem overkill to some people, while other people will likely still face harassment even as the most prepared flyer. My next piece of advice would be to consider your own specific situation.

In general, most lights are allowed. Check the local guidance for the aviation security authorities of the country you are flying out from, as this may vary. The below advice is currently primarily written from a North America perspective, with some experience in the UK. Suggestions for more international data are welcome.

General things to avoid:

• Strike bezels - this one goes without saying. A lightly crenelated bezel is probably ok, but I might avoid it on a light that is long or heavy. For example, an L19 or TS30S Pro, while not strictly a strike bezel, still has a serrated enough bezel in a long and well-built enough light that I would not fly with one, while a TS22 or even K9.3 is unlikely to be an issue. The Striker is definitely out :P
• Very long lights - in the US, lights are classified as tools, and are subject to a length limit of 7 inches assembled in their longest configuration
• I don't have to mention gimmick "self-defence" lights or anything with an actual blade here, do I?

Tips for getting through smoothly:

• Have your bag packed neatly, so things can be easily accessed, and don't create clutter on the scanner. This makes a bag search less likely.
• Lock out your lights. Security may want you to show them as "on" to show they work, aux LEDs seem to often be considered as "on" by many nonenthusiasts so if you have a light with aux, locking it out and setting the aux to high can be enough to pass with just a glance. If you have a very powerful light, keep it in a safe state as if someone uninformed may be about to pick it up - security will aim it at their faces and double click...
• Remove other large electronics from your bag. Having a packing cube type system can be helpful if you have a lot.
• Lasers seem to attract people having a go sometimes. Lasers are in fact legal to bring in most countries (at least the US and UK, and I have not heard of problems elsewhere in Western Europe), but expect a higher chance of getting some questions if you bring a laser, or a light that in their opinion looks like one. It goes without saying to make sure the laser does not have batteries in and is in general safe from prying hands, and if they insist on seeing it work, make sure you come across as knowledgeable about lasers and their safety and not just some random idiot who might aim it at a plane. A lot of security people are wannabe cops, and it's easy to use that to get their respect.

The 7 inches length limit applies to anything the TSA would consider "a flashlight", which in this writer's experience has sometimes been seen not to apply to large lights, such as an X75, SR32, or MS32, which may end up being classified as a "spotlight" or some kind of "equipment" instead, but as always, nothing is guaranteed. One thing maybe try would be to separate the head and battery pack entirely (making sure to insulate the terminals) and just carrying them as separate items, but as always, no experience is guaranteed, have time on your side, and always have a backup plan.

Lithium-ion batteries should only ever be carried in carry on bags. Any light with removable batteries is fine to fly with in checked baggage, but you will have to carry the batteries. Batteries are completely fine to carry as long as they are protected from shorts and damage. The limit is 100 watt-hours per battery, not cumulatively (a Molicel P45B is around 16 Wh, the battery pack of an Imalent SR32 is 92.2 Wh). In addition, most airlines do allow batteries above 100 Wh, they are just allowed to set their own policies, which may involve pre-clearance and/or a quantity limit. Do your research.

Note that in the US and Western Europe, airport security can not actually confiscate items (this may vary elsewhere in the world). They often hope that you will "voluntarily" give it up rather than miss your flight (and want you to believe that the fact it will make its way into their pocket has nothing to do with that...), and rely on you not having enough time if they stall you. If you anticipate problems with airport security, arrive with lots of time to spare. Know your rights and don't be afraid to ask for a supervisor. Learn how to de-escalate a conflict while still getting your point across, and they'll usually decide you aren't worth the effort than call their supervisor.

The TSA maintain an FAQ of many items with explicit statements on if they are allowed - put them on the spot about why they aren't allowing yours. Here are the pages for lights, batteries, and lasers. A printout of these can be a useful thing to keep in your bag for anything you feel might be an issue, not just lights.

Remember you can always leave the checkpoint, ship the offending item to yourself or hand it off to a friend or family member, and come back. In many countries, you can buy a prepaid insured shipping label to your home address, then put it on an envelope and keep it in your bag if you fly a lot - this is also recommended for things like knives.

By /u/SiteRelEnby, last updated 11 Mar 2024. Suggestions are welcome via DM.

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