Yes, in order to explain your idea a model will be helpful, which you can also take photos of to support your description online.
Consider using drone parts to build a cheap small scale functioning prototype.
Drawings can help, whether engineering or illustrations (what ever is cheaper to start) and support your description online.
Understand the trade off involved for VC money - how much equity and control you are willing to lose in exchange for this.
Figure out how much money would be required, even if only estimating the parts list at first, and what you need to be selling to determine if it's a potentially profitable venture before spending time on it.
How much are cargo drones costing? What can you learn from these?
How can you validate whether you've identified a buying market for this?