Recreating the P-40B: 3D Reference of the Fuselage (1)

At this moment I am working on second volume of my book about 3D modeling.  It describes building a 3D model of a WW2 aircraft on the example of the P-40B. Preparing for this work, I discovered that the original documentation of this early P-40 variant (also known as “long nose Warhawks”) is missing. On the other hand – you can find plenty of the “short nose Warhawk” blueprints (related to the P-40D later variants), as well as some P-36 drawings. I started by picking over 1000 original Curtiss blueprints and sketches related to the P-40, XP-40, and the P-36 from the vast resources of the AirCorps Library. Then I analyzed their contents, comparing them to the available historical photos. I described this process in this and following posts, written in 2019. Ultimately I traced side view of the P-40B. I also concluded that a 3D visualization of the available ordinals will be a better reference. In the previous posts I built such a reference for the SBD Dauntless. In this and the next post will I describe similar work on the fuselage of the early P-40 variants (P-40-cu, P-40B, P-40C).

I prepared an empty Blender file. For the convenience, I placed there my side view (from this post, see Figure 102-15). As for the SBD model, I assumed that 1 Blender unit = 1 in. For the main part of this fuselage, spanning from the firewall to the rudder, I used two P-36 diagrams. First of them (dwg 75-21-140) provides locations of the fuselage stiffeners at each bulkhead. There is also its modified variant (dwg 75-21-836) for the XP-40:

Figure 120-1 XP-40 fuselage stiffener dimensions (dwg 75-21-836)

The Book about Aircraft Reference Drawings Is Available

My new book on preparing aircraft reference drawings is already available in the web shops. This is the first volume of the new (fourth) edition of the “Virtual Airplane” guide:

Figure 115-1 Cover of the new book (“Preparations”) [fourth edition]

Differences between Dauntless Versions: Carburetor Air Duct

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:

Figure 94-1 SBD-5: the carburetor and its cowling (initial state)

Tracing Aircraft Skin Details: Center Wing and the Fuselage

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):

Figure 65-1 Traced panels on the center wing

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).

Modeling the Empennage (1)

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):

Figure 32-1 Modeling the root airfoil of the horizontal tailplane

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.

Modeling the Center Wing

On the first glance the SBD center wing section seems to be a simple rectangular (i.e. constant chord) wing, with modified leading edge (Figure 18‑1):

Figure 18-1 Center wing section — the basic shape

However, the landing gear openings visible on the photo can be difficult to recreate in a mesh smoothed by the subdivision surface modifier.

Differences between Dauntless Versions (SBD-5 and SBD-6)

In this last post about scale plans I will write about the modifications introduced in the SBD-5 Dauntless version.

For the reference, I placed below the drawing of the previous version: the SBD-4 (Figure 11‑1):

Figure 11-1 The previous SBD version (SBD-4 — described in the previous post)

(See the high-resolution SBD-4 left & top view).

Differences between Dauntless Versions (SBD-1…4)

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):

Figure 10-1 First version (SBD-1, built: 57, since May 1939)

(See the high-resolution SBD-1 left & top view).

My Drawings of the SBD: the Bottom View and Other Updates

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):

Figure 9-1 The SBD-5: side and bottom views

How Did I Draw the Top View of the SBD Dauntless

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.

Anyway, I started using everything I could, for example some photos from the restoration done by the Pacific Aviation Museum (Figure 8‑1):

Figure 8-1 Drawing the fuselage and the center wing section