After the demise of my Fire Fly 6, I've decided to build my own VTOL. I am using eCal to spec quad and plane engines and props. I know 1.8 thrust to weight is a decent place to start for the quad but I am not sure about the recommended thrust for plane. I've read it can be lower than a traditional plane. I am thinking .5 t/w woud be more than adequate but I don't know. This will be a mapping platform so high performace isn't required. Airborne efficiency is my primary goal. Any suggestions?