does anyone konw if the electircally actuated tip tank valve, that allows tip tank fuel to use the aux fuel system downstream of the aux tank via the aux selection on the FSV, is a soliniod activated/spring loaded open (to aux tank) type valve ? Can it be left permanently open without over heating ? I would like to operate with 10 gals in the tips and 20 in the mains to increase my useful load and have the equilivent of 60 gals of fuel availiable(ie full mains). I would like to keep the tip tank line to the aux fuel selecvter valve full of fuel so as not to suck air from the aux fuel system during the transition from selecting main to aux (tip tank).

That is really not a concern as the solenoid valve is in the cabin, mounted on the front of the spar. There is at least five feet of line to the aux tank. Further, there is a half cup of fuel in the selector bowl which can act as a very small reservior. I have never had a problem with the engine hiccuping on change, other than when I have run the tips dry and there is still air in that line.

Bernie, indirect answer to your question, the solenoid valves fail open to the aux tanks. It takes a working solenoid, (power and ground) to get the tip fuel out.

Regards

jvb

thanks for all the help( everyone)
bernie