systems should be inspected for worn or frayed
Main-Line Strainer
cables, damaged pulleys, and worn pulley
The main-line strainer must be drained at each
preflight inspection to eliminate any water and/or
sediment. The screen must be removed and
High-Pressure Fuel Lines
cleaned at the intervals specified in the applicable
technical publications. The sediment removed
from the housing should be examined thoroughly.
Since the fuel lines installed on the discharge
side of the engine-driven fuel pump are subjected
Particles of rubber are often early warnings of
to high pressures. You should take special care
deterioration of hose or self-sealing tanks. The
when inspecting for leaks and damage. The lines
strainer must be checked for leaks and damaged
gaskets.
must be properly connected; otherwise, units such
as the governor and barometric control will not
function correctly and may be seriously damaged.
Fuel Lines and Fittings
The lines must be inspected to see that they
are properly supported and that the nuts and
Combustion Chamber Drain Valve
clamps are securely tightened. A hose-clamp
The engine will have to be turned up to check
torque wrench should be used to tighten hose
the operation of the drain valve. If fuel does not
clamps to the proper torque. If this wrench is not
available, the clamp should be tightened finger-
run from the overboard drain after shutdown, the
tight plus the number of turns specified for the
cause should be determined.
hose and clamp. Clamps should be tightened only
when the engine is cold. If the clamps do not give
High-pressure Filter
a seal at the specified torque, the clamp, the hose,
or both should be replaced. After a new hose has
The high-pressure filter must be inspected for
been installed, the hose clamps should be checked
security of mounting, leaks, and proper safetying.
daily and tightened if necessary. When this daily
The filter element must be removed, cleaned, and
check shows that cold flow (the flowing of the
inspected at regular intervals. Regardless of their
rubber from the clamping area) has ceased, the
condition, filter elements must be discarded at the
clamps should be inspected at the less frequent
period(s) specified in authorized maintenance
periods specified for hose clamps throughout the
instructions. Whenever the element is removed,
system. The hose should be replaced if the plies
the housing should be cleaned and the seals should
have separated, if there is excessive cold flow, if
be replaced.
there are signs of chafing, or if the hose is hard
and inflexible. Permanent impressions from the
clamps in the tube or cover stock indicate excessive
Fuel Nozzles
cold flow. Hose that has collapsed at the bends
as a result of misaligned fittings or lines should
Periodically, the fuel nozzles and screens must
be replaced. Some hose tends to flare at the ends
be removed and inspected. The screens should be
beyond the clamps. This is not an unsatisfactory
cleaned and defective nozzles replaced. The
condition and does not indicate leakage. At each
inner surface of the exhaust cone must be
engine change, all hose connections forward of
inspected for heavy streaks--discoloration of the
the firewall should be inspected and defective hose
metal due to overheating. These inspections are
replaced.
rough checks for a combustion chamber in which
the fuel nozzle is not functioning properly.
Selector Valves
Selector valves should be rotated and checked
Ram Air Turbine, Hose,
for free operation, excessive backlash, and
and Reel Inspection
accurate pointer indicators. If the backlash is
excessive, the entire operating mechanism should
One of the inspections that is of importance
be checked for worn joints, loose pins, and broken
to you as an AD is the ram air turbine, hose, and
drive lugs. Defective parts in the operating
reel inspection. It is performed every 10 hours of
mechanism must be replaced. The cable control
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