Sequoia Aircraft Corporation F.8L Falco, Construction Manual

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F.8L Falco Construction Manual 17–5 Revision 4, March 1, 2002
You should understand that the elevator balance weight cannot be installed from the aft end of
the airplane through the spar—it simply will not fit (you may be able to get the weight only
through, but once the arms are riveted in position, it will not go). Since it must be installed from
the forward end, it must be bolted to the elevator control arm. Spacers are required, and these are
riveted to the arms so they they will not fall out during installation and removal.
To install the balance weight and arm assembly on the elevator, you will have to reach into the
inside of the tail section of the fuselage through the access door. A number of builders have
installed an extra access door for this purpose, but it is really not necessary. If the access door is
increased to 165mm in length, you can easily reach into the tail section and install the balance
weight assembly.
Note: A few builders have attempted to omit the spacers, to their eternal regret. Don't do
it! When the elevator is in the full up position, the lower elevator control cable must pass
between the two balance weight support arms.
As an alternative, the spacers may be riveted (or bonded with epoxy) to P/N 750. If
riveted, you will need a longer rivet. Countersink at both ends of the rivet hole, then set
the rivet and shave the “shop head” flush.
Figure 3
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Install the spacers on the elevator balance weight arms. See Figure 3. You will need to
sand the aluminum to the finished profile—a vertical belt or disc sander is best for this.
Drill the rivet hole with a 1/8ӯ drill. Ream the hole up with a No. 30 drill (.128ӯ).
Countersink (100°) the spacer on the inboard face and install the rivet. It would be a
good idea to paint the spacer with zinc chromate primer, and we prefer to install such parts
with wet primer between the parts while riveting to exclude moisture. As an alternative,
you could epoxy the spacers to the arms.
Figure 4
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Drill the spacers with a 5/32ӯ drill using the holes in the arms as a guide. Do this on a
drill press to make sure that the holes are drilled straight. See Figure 4.