Field boxes are an essential part of rc flight. As I graduate from backyard flying, the more I realize this. There is nothting worse than getting to the flying field close to sun-down only to realize you forgot something. Having the right tool/band-aid could make the difference of another flight or heading home. Here is a list of things I keep in my flight bag. I restock as items are used and complete a checklist from time to time to make everything is there.