Sequoia Aircraft Corporation F.8L Falco, Construction Manual

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F.8L Falco Construction Manual 26–1 Revision 4, March 1, 2002
Chapter 26
Fuselage Assembly, Part 1
General Comments
This chapter and all others that follow it are not really finished to the extent that we would like,
but we are releasing these chapters now so that you can benefit from the construction order
outlined here. The only thing really missing here is a list of spruce and plywood needed.
The fuselage is assembled on the jig shown in Drawing No. 321. This is used to hold the fuselage
frames in place while the longerons are fitted and glued in place. The fuselage will be built
around the jig, and the jig must be sawed apart to get it out of the airplane. When you first install
the frames on the jig, it is a very flimsy affair. When the longerons and stringers are clamped in
place, it becomes much stiffer. As the various parts are glued in place, the structure become
stronger and stronger.
This fuselage jig was originally designed by a Falco builder who built the fuselage separately from
the wing. The “one by two” cross members are adequate to hold the individual fuselage frames in
place, but you will need additional supports for the tail surfaces, the wing (with its frames), and
frame No. 1.
You should glue the vertical fin to the horizontal stabilizer before installing the tail group in the
airplane. This assembly will require some additional supports. An additional “one by two” may
be screwed to the bottom of the jig on the aft face of the forward fin spar. You should work out
these supports and try them before assembling the entire fuselage jig.
Many early Falco builders had a problem with their nose gear not fitting in the nose gear bay and
a considerable amount of re-work was necessary. This problem can be avoided by installing
fuselage frame No. 1 with the engine mount and nose gear in place. This allows you to position
fuselage frame No. 1 so that the nose gear is in the proper position. Because of the extra weight of
this equipment, the jig will require additional supports for this frame. You should work out these
supports and try them out before assembling the entire fuselage jig.
There are a number of ways to support the wing assembly with its fuselage frames. In the method
described in this chapter we use a padded cradle under each wing, but you should feel free to
develop your own method. Many builders support the wing assembly by using three jacks. Two of
the jacks are at the wing jack pads and a third jack is installed under fuselage frame No. 6. Since
the jacks are mechanical screw-type jacks, they are easily adjustable. Since you will need jacks
eventually for the airplane, this is a good time to make or buy some jacks. (One Falco builder
made his own of Sears floor supports welded to a heavy plate of steel at the base.)
Because the alignment of all of this will involve a series of small adjustments, the supports for the
wing assembly should have jack bolts installed for precise, fine adjustments. There are a number
of arrangements that work well. One is to install bolts in the “feet” of the wing or fuselage
supports as shown in Figure 6. The bolt head would contact the floor and a nut would be installed
to hold the support. The height of the support would be adjusted by turning the bolt while the
nut is held with a wrench. If you wish, you may glue the nut to the support with epoxy. There are
many variations possible on this idea.
You should also consider some way of firmly securing the jig to the shop floor. When you work on
the assembly of the fuselage, it is likely that you will bump against the structure and throw