Table of Contents
Advertisement
AUXILIARY FUEL SYSTEM
The auxiliary tanks are available in either of two
sizes; 20 U.S. gallon usable each wing or 31.5 U.S. gallon
usable each wing.
The auxiliary tanks are installed in each
wing just outboard of each engine nacelle and feed directly
to the fuel selector valves.
Fuel vapor and excess fuel
from the engines are returned to the main fuel tanks.
The
auxiliary tank is vented into the main tank. The main tank is
in turn vented to the atmosphere.
When the selector valve handles are in the AUXILIARY
position, the left auxiliary tank feeds the left engine and
the right auxiliary tank feeds the right engine.
The fuel
quantity indicator continuously indicates fuel remaining in
the tanks selected.
When the fuel selector handles are in
the AUXILIARY position, AUX TANK indicator lights will illu-
minate and the fuel quantity gage will indicate the fuel in
the auxiliary tanks (pounds in white and gallons in blue).
When the fuel selector handles are in the MAIN position, the
fuel quantity gage will indicate the fuel in the main tanks.
A three-position switch, spring-loaded to center, allows
checking fuel quantity in the tanks not selected.
The
switch, adjacent to the auxiliary tank indicator lights, is
labeled MAIN and AUX.
By positioning the switch to the
appropriate tank position, the fuel quantity in that tank
will be indicated on the fuel quantity gage.
If the auxiliary tanks are to be used, select fuel from
the main tanks for 60 minutes with 20 gallon tank and 90
minutes with 31.5 gallon tank prior to switching to auxiliary
tanks.
This is necessary to provide space in the main tanks
for vapc:r and fuel returned from the engine-driven fuel
pumps.
If sufficient space is not available in the main
tanks for this diverted fuel, the tanks can overflow through
the vent line.
Since part of the fuel from the auxiliary
tanks is diverted back to the main tanks instead of being
consumed by the engines, the auxiliary tanks will run dry
sooner than may be anticipated.
However, the main endurance
will be increased by the returned fuel.
The total usable
:tuel supply is available during cruising flight only.
An
engine failure or engine driven pump failure results in the
auxiliary fuel on the side of the failure being unusable.
Operation on the auxiliary fuel tanks near the ground (below
1000 feet AGL) is not recommended.
7-2
Advertisement
Table of Contents
