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The
layout of the fuel system is straight forward. As the fuel
tanks
in the AS5048 stub wings are higher than the original RAF48 which has a
lower aft spar,
the fuel flows out and down the 3/4" hose to the AN824 TEE
which rests at floor level, 3" lower
than the bottom of the tanks. Not shown in this photo, an
AN12 - AN6 reducer passes fuel to the 40 micron Proflow filter.
The two facet pumps can operate together or independently of
each other which provides redundancy and thus piece of mind.
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This is the
inside of the Proflow aluminum billet fuel filter. The
replaceable 40 micron filter is easily accessed by unscrewing the
T-6061 housing. |
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I
have made
bases for each fuel pump to bolt to. They are made of 3/32"
plywood with 1/8" foam acting to dampen any vibration. Two
counter sunk bolts hold the pump to the base which is epoxied to the
floor. Once cured, the pump is able to be removed in the
future if need be. These facet pumps do not have
anti-siphoning
or check valves which means if one pump fails, the second will be able
to draw fuel through it. I anticipate flying with both pumps
switched on and preflight testing them individually, much like you
would do with left and right magnetos. If a pump fails the
check,
it can be unbolted from the mount and replaced with a spare. |
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The
3/8" fuel line passes under the main spar beside the rudder cable.
The reason I am running the line through the cockpit is
because I
need easy access to a simple fuel shut off valve. I want the
ability to turn the fuel off in the event of an engine
fire, forced landing or an accident. As these facet
pumps do
not feature check valves, switching off both fuel pumps could still see
fuel flow through the line if the KR was at an unusual attitude after
an accident. eg. upside down. |
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I
decided to make my own AN12 - AN6 reducer so started with the AN929-12D
end cap and drilled it before threading it for the AN816-6-6D
nipple. |
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Here is the
finished product. More compact and less weight than screwing
3 or 4 reducers together. |
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Now
inside my reducer I have inserted the primary fuel strainer which would
have normally resided in each fuel tank. However, I could not
find a strainer to fit the 3/4" tank outlets. Having
it
fitted here also allows for easier access for checking rather than
inside sealed tanks. |
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Everything
fits neatly together. |
