As I wrote in previous post, I am working on a better drawing of the SBD-5. It is based on more than 1000 various photos. Below you can see the first version of the side view:
This is not an ultimate drawing: I suppose that it will be updated during my work, following the new findings about the airframe shape and/or details. The dotted lines mark the rivet seams, but size and spacing of these dots does not match the real rivets. I prepare these plans to build a model: that’s why I removed the outer wing section and horizontal tailplane. For these parts the most important drawing is the top view. To build them, on the side view I need the precise contours of their key sections (i.e. their airfoils as well as the incidence angles and spar locations). I draw three profiles: first of the wing root, then the root of the outer wing section, and then the wing tip. Two different sources specifies different wing tip profiles: NACA-2409 (Performance Test Report, 1942) or NACA-2407 (BuAer drawing, 1944). However, the bottom contour of the NACA-2407 seems to be a little concave. Because I did not observe such an effect on the photos, I decided to use the thicker airfoil of NACA-2409. I still have to verify this detail when I build the wing. The airfoils of the tailplane were specified nowhere. I copied its root airfoil from a photo.
While drawing the side view you still have to think “in 3D”, that’s why you can see around this silhouette some auxiliary sketches: the front view of the engine cowling, and the contours of the center wing section. I draw the latter element just to mark the exact position of the first rib of the wing. It was hidden inside the fuselage. Note that this airfoil was a specific modification of the NACA-2415 shape: the part of the wing that houses the main landing gear was reshaped. In the effect, the leading edge of the center wing section has a small downward inclination.
On the next week I will present side views of two earlier Dauntless versions: the SBD-2 and SBD-3. I will discuss where are the differences in the length of the SBD-5 and SBD-3, 4, as well as the mystery of the “missing 7 inches” of the SBD-2.
Within two weeks I will present the corrected/verified top view.