In my opinion fuels pumps belong in the fuel tank,
either the mains or collecting header tank.

Doug in Japan


Which means in my plane that a 'high-pressure' line will be running through
the cabin (RV-6) instead of a suction line.
Not sure I really like that...

BrianG
Iowa


Excellent point. Thanks for bringing that up. I almost
crossed over to the other side.
C. Smith

The point is that you could run a thick steel line through
the cabin area. If you break that you have other problems.
Bill Jepson

All fine and dandy, steel fuel line, more robust, also need to
buy tooling and fittings. Increased cost. I also have a 4 tank
system, likely that the fuel selector valve will be located in a
structure below the cabin. A leak in a suction line typicly
draws in air, not spray out fuel, until the pump is shut off.
Then it becomes a small dribble (depending on size), hopefull
the now leaking fuel will be smelled by the user during
preflight on the next use. Also a steel line can be affected by
vibration fatigue, although not a likely concern with a rotary.


C. Smith
Good arguments can be made for both systems. The point is that
either system needs to be well engineered to work well. An in
tank system prevents vapor lock problems. A FWF system can
prevent some failures also. When I raced motorcycles I built my
own SS braided brake lines. The connections are a possible
failure point but I TESTED them. When your life will depend on a
system test, and use the best materials available. I like the
pump with good fittings. That is probably a good way to go if
you use a FWF pump system. One advantage of the in tank system
is that it can be single line. (no return) Care is required
whichever route chosen.

Bill Jepson