A symple +- 4H print drop system you can attach to your rc plane or drone. Needs a 9g servo and some 1-2mm metal bars (servo rods). 1 short for the servo and a longer one for the door hinge. There is a thick and thin door. Normally thin should do the job and it prints faster. I just used double sided tape and ducttape to attach it to my 3d lab print P-51 so i can remove it easily. Have fun dropping candy or whatever. Don't use this for dangerous things, let's keep the hobby safe and legal.
This is a link to my yt vid where you can see how it works: