After “mounting” the R-1820 engines into my SBD models, I decided to recreate some details of the inner cowling (the cowling panels placed behind the cylinder row). In this post I will form the missing parts of the carburetor air ducts, hidden under the NACA ring. There are significant differences in this area between various SBD versions, which never appeared in any scale plans, or in any popular monograph of this aircraft. I think that the pictures presented below highlight these differences. They can be useful for all those scale modelers who are going to build the SBD “Dauntless” models with the engine cowlings opened. (Sometimes you can encounter such advanced pieces of work on the various scale model contests).
Let’s start with the SBD-5s (and -6s), which are better documented (because they were produced in much larger quantities). They had a dual intake system, of the filtered/non-filtered air, which I discussed it in the previous post. I already recreated the two intakes of the filtered air, placed between the engine cylinders. Now I have to create the central, direct air duct and its opening at the top of the internal cowling.
Figure 94‑1 shows the initial state of my SBD-5 model:
This week I continue mapping the SBD-5 Dauntless skin panels onto my model. After tracing the outer wing sections, described in the previous post, I traced the center wing section (Figure 65‑1):
As you can see in the picture, I also traced the contours of the wheel bay on the wing surfaces. (These openings disappear, when you enter mesh edit mode, because they are dynamically created by Boolean modifiers. Thus such contours will be useful during further work, because in this way you can see these edges while editing the mesh).
The horizontal tailplane has similar structure to the wing — but it is simpler. Thus I started it in the same way as the wing, by forming its root airfoil (Figure 32‑1):
In the most of the aircraft the tailplane has a symmetric airfoil. So it was in the Dauntless. I did not find its signature (family) in any of the reference materials, thus I carefully copied its contour from the photos (its rear part — the elevator — seems to have modified shape, anyway). It has incidence angle of 2⁰, so I rotated the rib object and used a Mirror modifier to generate its bottom part.
To recapitulate my work on the Dauntless plans, I decided to draw all the external differences between its subsequent Navy versions. Because of the numerous changes that occurred in the SBD-5, I decided to split this description into two posts. This is the part one, the part two (about the SBD-5 and the SBD-6) will be ready in the next week.
NOTE: All airplanes on the drawings below are equipped with the small tail wheel with solid rubber tire (for carrier operations). However, for ground airfields Douglas provided alternate, pneumatic, two times larger wheel. These tail wheels could be easily replaced in workshops.
Starting from the beginning: here is the SBD-1, the first of the Douglas Dauntless series (Figure 10‑1):
During previous weeks I was working on the bottom view and other details of the SBD Dauntless. For example — I added a modified side view that reveals the engine and the cowling hidden under the NACA ring (Figure 9‑1):
Drawing the vertical views (from the top and bottom) of the SBD Dauntless was more difficult than the side view, because there were no “vertical” photos which you can use to verify and enhance the available plans.
In my previous post you can find the updated scale plans of the SBD-5 Dauntless, consisting the side and top views. The ultimate shape of depicted airplane resulted from matching my initial drawings against the Douglas general arrangement diagram. I couldn’t do it before, because this diagram comes from the Dauntless maintenance manual, which I received in previous week.
In this post I will show you how I do such a matching using the diagram shown below:
This Monday I finally got the “Instructions for the Erection and Maintenance of the Model SBD-6 Airplane” book – more than 600 pages about the Dauntless, published by Douglas in March 1944. Because of the lengthy title, I will refer to this book as the “SBD Maintenance Manual” or the “Douglas manual”. In spite that it describes the last produced version, it is also usable for the earlier models: as I mentioned in one of the previous posts, the SBD-1 airframe behind the firewall differs only in a few details (the double gun mount, gunsight type, lack of the YAGI antennas) from the SBD-6.
Inside you can find the SBD-6 general arrangement drawings, as well as the stations diagram (Figure 6-1):