I am possibly going to film the New Year's fireworks around a crowd of thousands of people in an event, and I'm assuming all of them will have their phones, posting on instagram, etc etc. That plus the avenue having a few antennas... Should I worry about interference during flight? And if there's interference, what should I expect the drone to (mis)behave and correct the flight to avoid a crash?

Should I worry about interference during flight?
Not much.
Interference is common in urban areas.

And if there's interference, what should I expect the drone to (mis)behave and correct the flight to avoid a crash?
No, your drone won't crash due to interference.
The main issue is that interference would reduce the distance you can reach with good control signal.

Thank you! So flying close to a crowd of over 10 thousands of people with their phones shouldn't add to issues?

My buddies RC 2 controller and mine interfere with each other if we stand within I'd say 10 feet of each other, but I've never seen my phone interfere.

Hi there. Thank you for reaching out. There are various sources of interference when flying the drone in different types of environments. You may check the information below:

(1) 2.4 GHz:
1) Co-channel interference: This includes interference from commonly-used Wi-Fi, early versions of Bluetooth, intercoms and other private communications.
2) Adjacency channel interference: The attenuation, interference, etc. of a wave during propagation will "invade" the adjacent frequency bands, which is also the main form of interference.
Interference sources: Mobile devices (including conventional communications and hotspots) and mobile base stations (3G and 4G) for mobile phones.
3) Scenarios in which a flight is not recommended are as follows:
a. Crowded areas as they will contain many mobile devices;
b. Mobile signal base stations including signal trucks;
c. Municipal traffic wireless monitoring points;
d. Urban building clusters;
e. Construction zones (where there may be intercoms);
f. Areas blocked by obstacles.

(2) 5.8 GHz:
1) Co-channel interference: These include interference from Wi-Fi in the 5.8 GHz band, Bluetooth technology developed in recent years, etc.

2) Adjacency channel interference: The attenuation, interference, etc. of a wave during propagation will "invade" the adjacent frequency bands, which is also the main form of interference.
This interference will gradually increase with the development of 5G.
3) Scenarios in which a flight is not recommended are as follows:
a. 5G mobile signal base stations including signal trucks;
b. Large urban office building clusters;
c. Areas blocked by obstacles;
d. Other emerging 5.8 GHz emission sources such as Wi-Fi routers, network cards, etc.

Hm... Let's say I flew in all the conditions above... Except signal trucks, unless you mean Signal Trucks as reporters live on scene, which then, yes, 100% I was.

Also it was pretty much okay, BUT I only flew 2 sessions of 4 minutes. Positioned myself in a crossway, so it would get a LITTLE bit of more sky. All buildings are at least 40 meters tall. Lost GPS constantly, had some RC interference, but Mini 3 hold pretty well. I did not well, I thought I was gonna throw up bc I was so nervous lol

DJI Paladin thank you so much for your detailed response! I think maybe I'll prefer 5.8 band then, these seem to be the less interfered. Or should I keep it in Dual Channel? actually, when do I ever not go Dual-Channel?

BY THE WAY Not saying it's FINE! I'm saying I did and I will try not to in the future, that could've ended really bad for me and other people. That was probably very stupid.