We're getting ready to test a ferry tank system in a IV-P.  It
consists of a Turtle Tank bladder in the cabin, a valve, a 30GPH Facet
pump, and plumbing to the right tank.

The plan is to open the valve and just let the pressurization squeeze
the fuel in to a partially-drained wing tank.

The pump is to transfer fuel in the event of cabin de-pressurization.

Some of the issues I'm concerned about are:

Adequate transfer rate.  Ideally it would be greater than the use rate
to reduce fuel management planning.  All the plumbing is AN6 except
for the tank inlet fitting and pump adapter fittings, which are AN6 to
1/8 NPT.  I would have preferred 1/4 NPT.

Pressurizing the wing tank.  The tanks have the standard under-wing
NACA vents without check valves.

Changes in fuel pressure if the tank vents too slowly and therefore
creates additional fuel pressure.  I'm not sure how much change in
head pressure the metering system can tolerate without affecting how
the engine runs.

I've removed the vent check valves--thank you Colyn!

If anyone has experience or suggestions, I'm all ears.

Thanks,

Dave Saylor
AirCrafters
140 Aviation Way
Watsonville, CA 95076
831-722-9141 Shop
831-750-0284 Cell