"Mandatory" mods tothe D.H. Vampire
I've got both the PNF Vampire and the ARF Vampire for parts and experiments. The plane flies great! But, definitely plan on your C.O.G. being at 298 mm from the tip of the nose, not 310. Or mark the COG at 10 mm in front of the tips of the twin tail booms - at least to start. Reinforce both tail booms on the bottom with C.F. Finally, I've had some problems with my downwind turns, especially when the battery is getting a bit low but still sounds like it's running well. Keep your speed up and make your turns up high for the first 10 flights. Good luck!