Remember, we are working forward from the elevator
surface. The push-pull rod connecting the bottom of
the rear stick with the bell crank must be adjusted until
the stick center line is the prescribed number of degrees
forward of a vertical reference line. See the vertical
reference line (14) and the center line (15) in figure
16-26. The vertical reference line is a position that the
center line of the control stick would attain at a
90-degree angle (19) to the cockpit floor (20).
Adjust the length of the push-pull tube between the
control sticks to position the front control stick to an
Figure 16-27.--Elevator rigging fixture.
angle identical to that of the aft control stick. Then,
remove all three rig pins. This completes the rigging
properly mounted, the index marks (graduations) on
and adjusting of the control system to neutral. All that
the curved section align with the elevators and indicate
remains is to adjust the stops that limit the fore and aft
the position, in degrees, of the elevators. If, with the aft
travel of the control sticks, and rig and adjust the
sector rig pin in place, the elevators are not in neutral
bungee that holds the system in the neutral position.
(for example, 5 degrees above the neutral mark),
lengthening the push-pull rod end will push the
The stop bolts (2) (fig. 16-26) are located in front
elevator fitting assembly forward, and thereby lower
and behind the aft control stick. They are installed so
the elevators. If the elevators are too low, then
that the stick hits the stop bolts at the extreme limits of
shortening the rod will bring them up as required.
its travel. The maximum travel of the elevators in each
The next step is the adjusting and tightening of the
direction is determined by the manufacturer and is
pair of cables in the system. This is accomplished by
controlled by the stop bolts. With the rigging fixture
tightening the turnbuckles on each cable evenly until
still in place, move the control stick all the way
the required tension is obtained. During cable
forward, and adjust the stop until the elevator DOWN
tightening, the rig pin is retained in the aft sector,
throw conforms to the MIM. Pull the stick all the way
leaving the forward sector free to turn. Therefore,
aft, and adjust the aft stop bolt to obtain the correct
when the necessary tension is recorded on one cable,
elevator UP throw. The stop bolts are safety wired in
that is also the tension on the other cable. To ensure that
place after this adjustment.
the cables were tightened evenly, check the forward
sector rig pin hole to see if the rig pin can be inserted
The last item to be adjusted in this control system is
through the sector and into the structure. If this is not
the centering bungee. Connect the bungee and adjust
possible, then the cables must be adjusted by loosening
its rod end so that with the stick against the stop bolt in
one and tightening the other. This will maintain the
the full down elevator position, the bungee is a
correct tension on the cables, and, at the same time,
minimum of 1/32 of an inch from bottoming. After this
rotate the forward sector to the neutral position. The
adjustment, the elevators should be held in neutral
cable section is properly rigged when it is possible to
(plus or minus the prescribed number of degrees) by
insert and remove the forward sector rig pin easily with
bungee action. If the elevators are too high, shorten the
the aft sector pin installed and the cables tightened to
bungee rod end. If they are too low, lengthen the
the prescribed tension.
bungee. With the bungee properly adjusted, tighten the
The push-pull rod connecting the forward sector
bungee rod end locknut and safety wire it.
and the bell crank is adjusted to the correct length by
installing a rig pin in the bell crank. Then, the rod
CABLE FABRICATION
adjustable eye is turned in or out until the rod can be
installed between the sector and bell crank without
Control cables are fabricated mostly of extra
binding. At this point three rig pins are in place, and
flexible, preformed, corrosion-resistant steel. Control
should remain in place until the control sticks are
cables vary from 1/16 to 3/8 inch in diameter. Cables of
rigged to neutral.
1/8 inch and larger are composed of 7 strands of 19
wires each. Cables 1/16 and 3/32 inch in diameter are
When you are positioning the control sticks to
n e u t r a l , t h e r e a r s t i c k m u s t b e a d j u s t e d fi r s t .
composed of 7 strands of 7 wires each.
16-31
