Question: What is the purpose of the small fins under the fuselage on the Texan II and Harvard II 40 ARF? Where do they attach to fuselage?

Answer: They are largely decorative. The real aircraft has them and we wanted to have a model that was as scale like as possible. They may also be helpful at high speeds when using larger engines. Please see the attached PDF for location information.

Better Answer: For most situations the fins can be installed or not depending on if you want the model to really look as close as possible to the real thing. The full size aircraft does have these fins. If you are using a 60 size engine on the model you may find that the fins help with lateral stability at high air speeds. The model will "groove" a bit better at high speeds and have more yaw stability... in effect the fins increase the size of the vertical stabilizer slightly. Please note that the ventral fins are not normally provided with the PC9 versions of this model.