The Curtiss R-9 was a twin float plane bomber that was based on the earlier Curtiss R-6, but with the pilot and observer’s positions reversed.
The R-6 was an improved version of the earlier Curtiss R-3, which had been the first version of the Model R to introduce a longer three bay biplane wing, with straight wing. The R-6 had three degrees of dihedral on the outer wing panels, and used a more powerful 200hp V-2-3 engine. Like the earlier model it’s two crew sat in widely separated cockpits, with the observer sitting between the wings and the pilot in the rear cockpit.
The R-9 was structurally identical to the R-6, but with the crew positions reversed, so that the pilot was in the front, and the bombardier/ observer was in the rear. All sources describe the R-9 as a bomber, but frustratingly none of them describe how many bombs it could carry, or how they were carried. It isn’t entirely clear which engine was used in the R-9, with the 200hp V-2-3 engine the most likely, but some sources suggesting they might have used the Liberty engine also used the R-6L.
A total of 112 R-9s were produced, all originally for the US Navy, with the serial numbers A873 to A984.
Ten of these aircraft (A883-A887 and A901-A905) were transferred to the US Army in February 1918, where they were given the new serial numbers 39033-39042. These aircraft went straight to the Army from Curtiss.
Fourteen of the Navy’s aircraft (with scattered serials) were later converted to the R-6L standard, which involved giving them a 360hp low compression Liberty engine, and were used as torpedo bombers. It isn’t clear if they also had the positions of the crew swapped back.
Crew: 2 – pilot and observer
Span: 57ft 1 3/16in
Length: 33ft 5in
Height: 14ft 2 1/32in