Since a standard size Patriot flys fastest on a 9 to 10" dia prop depending on engine. Why all this discussion about 16 to 18" Props
Even a 50% scaled up Patriot should should be fastest with 11 to 14" Props. If a Rossi 90 RIRE turning a 12X9 at 14400 won't make it fly fast and accelerate straight up; The model is way too heavy and draggy!