Hossfly

If you just must have fuel tubing to do what you think needs to be done, then go to SIG, http://www.sigmfg.com/cgi-bin/dpsmar...FV4.html?E+Sig, and get yourself some SURGICAL TUBING to fit your desired equipment.

Then you just might find that good ol' Montague was the man to listen to.

Now good ol' 'opjose' may be on track also, however in 60 years of playing with toy airplanes from CL, FF, and RC including CL Stunt Competition where fuel management was of ultra-extreme importance to assure a stopped airplane (no throttles, just needlevalves) 8 minutes from first prop flip, to pylon racers to Pattern, sport etc., etc., I have never expereinced fuel problems that required a clunk to go to the nose of the tank. Actually just the opposite.

An aircraft in a vertical dive is constantly accelerating under the gravity acceleration schedule as is the mass of the fuel in the tanks. Drag being produced at 1/2 the square of the airspeed, constantly retards that acceleration of the flying machine.
As one that has been supersonic in a vertical dive, as well as near zero speed at the reversal of maneuvers such as a flop-over from a vertical tailslide, I have never experienced any looseness of the shoulder-harness during the vertical descent portion of any such maneuver. My RC experience for 31 years of RC leads me to believe that the fuel also stays firmly planted near the lower aft portion of the tank, aft being the portion closer to the earth.
Of course when performing maneuvers exceeding 1G, the other factors come into play. Fuel and clunk follow the higher forces. It really doesn't take a lot of G force to move things around, so a fuel line like surgical tubing can tie itself into a knot in short order, however one must do as one thinks best!!!
Of course some Professor of Physics from John Hopkins University, having flown an RC across the Atlantic Ocean plus several other record performances, may well be able to dispute my theories.

edit: add 1G+ info.