Cessna 172R, Руководство по эксплуатации

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CESSNA
MODEL
172R
SECTION
8
HANDLING, SERVICE
& MAINTENANCE
One exception
to this can be encountered when operating
under
rthe combined
effect of: (1) use of certain fuels, with
(2) high
humidity conditions on the
ground (3) followed by flight at high
altitude and low
temperature.
Under these unusual conditions, small
amounts of water in solution can precipitate from the fuel
stream
and freeze in sufficient
quantities to induce partial icing of the
engine fuel
system.
While these conditions are quite
rare and will
not normally
pose a
problem
to owners and
operators, they
do exist in certain areas
of
the world and consequently
must
be dealt with, when encountered.
Therefore, to help alleviate the possibility of fuel icing occurring
under these unusual conditions, it is
permissible to add isopropyl
alcohol or diethylene glycol monomethyl
ether (DiEGME) compound
to
the fuel supply.
The introduction of alcohol or DiEGME
compound into the fuel
provides
two
distinct
effects: (1) it absorbs the dissolved
water from
the gasoline and (2) alcohol has a
freezing temperature depressant
effect.
NOTE
When using fuel additives, it must
be remembered that the
final goal is
to
obtain a
correct fuel-to-additive ratio in the
tank, and
not
just with
fuel coming
out
of the
refueling
nozzle. For example,
adding 15 gallons of correctly
proportioned fuel
to a tank which contains
20
gallons of
untreated
fuel will result in a lower-than-acceptable
concentration level
to
the 35 gallons of fuel which now
reside in the tank.
Alcohol, if used, is
to
be blended
with the fuel in a concentration
of
1%
by volume. Concentrations
greater
than
1%
are
not
recommended since
they
can
be detrimental
to
fuel tank materials.
The
manner
in which
the alcohol is added
to
the
fuel is
significant because
alcohol is
most
effective when it is completely
i#*' dissolved in the
fuel. To
ensure
proper mixing, the following
is
recommended:
1. For best results, the alcohol should be added
during the
fueling operation by pouring the alcohol directly on the
fuel
stream
issuing from the fueling
nozzle.
Feb
28/00
8-17