Hmm, isn't the idea of letter bombs that the bomb is literally within arm's length, whereas that sort of proximity for a noisy drone, keeping it close enough to a possibly moving target, while setting it off may not be super practical. It may be more realistic to get within, say, 10 meters?

Also, no way the FAA would issue waivers for this sort of mission. /s

Yes, this is certainly a part of problem constructing it.

I would imagine that replacing the motors and adding larger battery while keeping the control system shouldnt be an issue.

Also within an article there is a picture of a box with 4 motors, if lower part would be made from something like copper, it could be used as shaped charge [1] or adding shrapnel would also be an option. Or just make it to carry the normal hand grenade. The noise is surely an issue if you dont keep the distance, so I would imagine that you fly high over the target and then go into free fall.

In either case, this has a potential to become something really nasty.

Anyway, enough of this talk, it is surely an interesting technological challenge and interesting debate, but there are some really sick people on this planet and I dont want to give them any ideas. Also I bet there are some red lights blinking in some 3 letter agency somewhere :D :D :D

[1] https://en.wikipedia.org/wiki/Shaped_charge

A phone network is no use - latency means it’s useless for visual realtime control of a drone and you could just store a gps waypoint route on the flight controller and save the 4g modem weight if you meant as a mission control mechanism.

Achieving the precision of someone holding a letter would be remarkably challenging. Source: racing drone pilot for 5+ years.

Forget visual - DIY (semi-)autonomous drones are doable today and could be pretty scary too. 4G may not be good enough for a human pilot flying FPV but it’s likely more than enough for a drone with GPS running Ardupilot to hone in on a target tagged with a planted transmitter or bugged phone.

Hobbyists have been documenting step by steps for this since 2008, nothing you’re suggesting is remotely new.

Why hasn’t it happened? What is the part of the movie plot imagination that doesn’t translate quite as well to real life?

I'm not sure, tbh, though I suspect it's due somewhat to the general technical incompetence of (terrorist & gang) organizations. Bright people aren't exactly attracted to the idea of joining an organization which doesn't value life highly, and the bright ones that do enlist may be likely to be conscripted to work on other projects or killed by enemies/rivals. It's doable by hobbyists, but doing it with the scale/accuracy needed to be dangerous is a complicated endeavour that doesn't lend itself well to this kind of organization.

Fly a drone carrying a 500gram camera behind a tall building. You’ll learn the 6 things that stops this whole idea working. It’s consigned to the movie plots for the foreseeable future.

Think a lot of these comments don't take into consideration how cheap these drones can be made, especially if you have add a 3D printer into the mix.

Printing the air frame is a huge cost saver.

Cheap motors are everywhere, plenty of places to scavenge tiny hobby motors (doesn't have to fly super fast or lift 2000 grams)

Cheap arduino's for brains and motor control, not much to it.

You can get away with having a tiny lipo battery for powering the motors since it's a one way trip for the drone anyways...

With the right choice of materials you could get a drone BOM down to $100-150 [not included transmitter remote control] Needless to say, having a cartel budget you can really pump up production to few 100 a week if needed....

Making sumthing that's going to be used for a one way trip isn't hard, when your objective is to make a impact on target.

This is the new battlefield.