Figure 7-3. Measuring Control Surface Angle at Full Throw
7-3. Cable Tensiometer. Control surface movements
must be synchronized with the movements of the
cockpit controls. To accomplish this, the flight controls
must be rigged. To properly rig control surfaces, a
protractor must be used to check the throw of the
surfaces, and a cable tensiometer is used to check the
tension of the flight control cables. The use of a
protractor is discussed in paragraph 7-2. The following
paragraphs describe the cable tensiometer and the
techniques for its use.
a. Description. Several manufactures make a variety
of tensiometers. Each type is designed for different
kinds of cable, cable sizes, and cable tensions. A
typical tensiometer is shown in figure 7-4. Cable tension
is determined by measuring the amount of force needed
to make an offset in the cable between two hardened
steel blocks, called anvils. A riser or plunger is pressed
against the cable to form the offset.
b. Use. The following steps outline the general
tensiometer (see figure 7-5):
(1) With the trigger lowered, place the cable to be
tested under the two anvils.
(2) Close the trigger. Movement of the trigger
pushes up the riser, which pushes the cable at right
angles to the clamping points under the anvils.
(3) Read the force indicated on the dial.
Figure 7-4. Tensiometer