Curtiss R-6 The Curtiss R-6 was a twin float observation plane that was a more powerful version of the earlier R-3, and that was the first US Navy aircraft to see service overseas. The R-3 was the first float plane version of the Model R. Like the R-3, the R-6 was a three bay biplane, with unequal span wings. The two main differences were that the outer panels of both wings had three degrees of dihedral, and it was powered by a 200hp V-2-3 engine. Otherwise it used the same straight edges…