Modeling Empennage Details

After the previous post I decided to simplify the empennage fairing. Originally I created it from two separate objects: the fin fairing and the tailplane fairing, split across their fillet. Now I decided to eliminate this troublesome seam by joining these two meshes into single object (Figure 37‑1):

Figure 37-1 Initial merge of the two fairings

I will split it later, along the bottom rib of the fin (there was another panel seam in the real airplane). To simplify creation of the original overlapped panels, I simultaneously split the fin into the forward and the rear part, along one of the original seams.

As you can see in Figure 37‑1, there are the same number of spanwise edges on both fairing meshes. It is a matter of sheer luck, but it makes the process of joining these two parts much easier.

First, I modified these edges, bringing them closer to each other. (I did it by sliding their vertices along perpendicular edges — as you can see in Figure 37‑2a):

Figure 37-2 Adjusting mesh topology around the future seam

Then I removed the unnecessary faces (as in Figure 37‑2b).

Finally I filled this gap with new faces, effectively merging these two meshes (Figure 37‑3a):

Figure 37-3 The merged mesh of the tailplane fairing and the fin fairing

In the side view (as in Figure 37‑3b) you can see that the forward part of the fin extends a little the panel line visible on the reference drawing. It will be overlapped by the forward part, which will end precisely along the original seam. (Such an overlap is visible on the photos). Note also that the seam along the fuselage upper panel (marked on the drawing by the dotted line) is somewhat higher than on my scale plans. This is the effect of the modification that I made in the upper part of the fuselage (described in my previous post). My reference drawings are simply wrong about its location in the side view.

I think that the empennage fairing looks much better after this modification (Figure 37‑4):

Figure 37-4 Further modifications made to the fin and fairing

It fits well all the three elements it joins: the fuselage, the fin and the tailplane. The fillets looks smooth and natural. As you can see, I split the fin and the fairing along the bottom rib edge, as I planned. (There was original panel seam). I think that this new arrangement of the model objects will facilitate further detailing of this assembly (for example, now the forward fin panel overlaps the other elements, as in the real airplane).

The last element of this assembly is the fin tip: in the real airplane it was stamped in one of the fuselage inspection doors. I started to form this part by creating a plain, rectangular cover placed over the fuselage, and separating the corresponding fragment of the fin tip (Figure 37‑5a):

Figure 37-5 Forming the cover at the fin tip (1)

Then I joined these two object into a single mesh (Figure 37‑5b)

In the next step I adjusted corresponding edges of both elements, and removed the unnecessary faces (Figure 37‑6a):

Figure 37-6 Forming the cover at the fin tip (2)

Finally I filled this gap with new faces. Finally, after some rearrangements of the mesh topology, the resulting elements looks like in Figure 37‑6b).

Figure 37‑7 shows the final object, fitted to the fin and the fuselage:

Figure 37-7 Finished fin fairing

The last element that I need to finish in this empennage is the rudder leading edge. I created it in the same way as the leading edge of the elevator: from a single circle (see this post, Figure 33-9). I extruded it into a cone (Figure 37‑8a), then removed the unnecessary faces and created new ones (Figure 37‑8b):

Figure 37-8 Creation of the rudder leading edge

Figure 37‑9 shows the completed empennage (note that I also created the fin spar):

Figure 37-9 The completed empennage

The last missing element is the tail tip. It has a rather complex shape, so I started modeling this part by copying its outer edges from the fuselage, fairing, rudder and elevator. You can see them in the picture above. I do so when I have no clear idea how to start. In the next post I will describe what I did next.

In this source *.blend file you can evaluate yourself the model from this post.