wvmarle:
At 5-10m you can still experience some serious swing - just a little gust of wind can be enough.And yes, an emergency release would be quite essential. All helicopters carrying loads have that as well, if the load becomes too unbalanced the pilot can release it. In your case, maybe a line cutting mechanism would be the easiest to implement (and least weight).
Yes, I'm looking into methods for creating some type of line cutting mechanism. I'm not sure what would be best to use here. Has anyone over heard of something that would work well for this? Maybe something that is made for hobby RC helicopters? Ideally it could be controlled over PWM as that's the protocol used on the flight controller already on-board the drone I'm using. I've also considered some type of Arduino (or other micro-controller) controlled laser or heating element. I'm planning on using kevlar filament for the line though and it has a melting temperature of about 800ºF, so I worry a small heating element or laser may not be reliable enough. Also, if the string is swinging around even a small amount it may not line up well with a laser or heating element...