While rigging the fuel selector, power control,
3. Have all of the appropriate caps and plugs
and shutoff valve linkages, you should follow the
available to prevent the contamination of open
step-by-step procedures for the particular aircraft
fuel lines during component replacement.
model being rigged. The cables should be rigged
4. Have parts bags and tags available to keep
with the proper tension with the rigging pins
all removed nuts, bolts, and washers in one
installed. The pins should be removed without any
location, and be sure to tag all fuel lines before
binding; if they are hard to remove, the cables
removal. This makes reinstallation much easier
are not rigged properly and should be rechecked.
and less confusing.
The power lever should have the proper cushion
5. If the removed component is to be turned
at the IDLE and FULL POWER positions. The
into supply, make sure it is purged and filled with
pointers or indicators on the fuel control should
an approved preservative before turn-in.
be within limits. You must take all of these things
into consideration while rigging or adjusting the
RIGGING AND ADJUSTING
parts of the fuel system. Also, the fuel selectors
must be rigged so that they have the proper travel
This section covers some of the basic
and will not restrict the fuel flow to the engines.
inspections and procedures to be used in the
Rigging the fuel control of a turbojet engine
rigging and adjusting of fuel controls, fuel
is an exacting job. The power lever assembly and
selectors, and fuel shutoff valves. Inspect all bell
its related linkage provide manual control of the
cranks and rod bearings for looseness, cracks, and
engine thrust. The power lever assembly is located
corrosion. Particular attention should be given to
in the cockpit, and its related mechanical linkage
the rod and bell cranks where the bearing is
connects it with the fuel control unit of the engine.
staked. This area is subject to stress cracking and
Positioning the power lever at any selected setting
corrosion. The adjustable rod ends should be
mechanically actuates the linkage to the fuel
inspected for damaged threads and the number
control unit, resulting in the desired engine thrust.
of threads remaining after final adjustment. The
Modern jet aircraft use various power lever
drums should be inspected for wear, and the cable
control systems. One of the common types is the
guards should be checked for proper positioning.
cable and rod system. In this system, you will find
If the cables have been loosened, the tension
bell cranks, push-pull rods, drums, fairleads,
should be set.
Figure 4-29.-Engine power control system rigging.
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