Message
Here's another way
to rig the fuel system. On my 320 (not built by me) there is the standard
Facet pump to the header arrangement for each wing tank. However, there
are also direct feed lines (3/8" al) from the wing tanks to the fuel
valve. These have their own pick-ups in the tanks. The fuel valve is
4-way: left tank, header tank, right tank or off. I can pump to the header
from either wing, or I can feed the engine fuel system (IO-320 with mechanical
pump and electric boost pump) directly from any tank. The mechanical pump
pulls from the wings just fine. The only time I use boost is on take-off,
and that's for the standard safety reason in case of mechanical pump
failure. I have accidentally taken off without the boost on and it runs
fine. The only time I use the transfer pumps is when I forget to switch
from the header to a wing tank after take-off. I like to keep the header
full as my reserve, and just in case I can't get fuel out of the wings for some
reason.
Quite frankly, I
have been considering taking out the transfer pump system. I really don't
like all those plastic fuel lines in the cockpit with me (I'd rather not have
the header in there with me, either!). Right after I bought the plane I
had a scary experience with the plastic lines. I had just topped off all
the tanks and was taking off for a cross-country. As I was climbing out I
noticed raw fuel dripping from the bottom of the instrument panel right below
the header sight gauge. YIKES! I quickly turned off the master
switch and landed back. Upon inspection, I found that the plastic line
from the header that forms the sight gauge had cracked right at the end of the
aluminum tubing out of the top of the header. The sight gauge tubing and
the the tubing from the Facet pumps (10 years old) was all hard as a rock!
Not having the time at that point to engineer an electric fuel gauge
replacement, I had the sight gauge tubing replaced. I also had the
transfer lines inspected. The A&P recommended replacing the transfer
lines also. I planned on doing that at the next annual. But the
plane is down for a prop replacement right now, and I'm looking at all that hard
plastic tubing snaking around in the bottom of the cockpit and up behind the
panel. Seeing that plastic tubing running through the jumble of wires
behind the panel just gives me the willies!
So my dilemma is, do
I take out a functional system that, in my case, is more of a redundancy
than a primary system, or do I spend about $500 on A&P time to replace
it?
Happy holidays
all!
Lee
Metcalfe
N320WH Kansas
City
472 hrs. - still
waiting for the prop (due any time, now!)
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