Dene Collett wrote: > Larry do you have any internal baffle plates in your tanks? > I am also considering utilizing the now hollow D-box space for a tubular > tank that will also be full span. This will practically eliminate any CG > shift as fuel burns off.
My tanks are between the spars and the total CG change is less than an inch, which is imperceptible during a flight, at least to me. Done in the right proportions though, you can have zero CG change if it's that important (and I don't think it is). I assume you're talking about reducing the length of the between-the-spars tanks and adding partial length tubes to the front of the spars. I think 5" irrigation pipes will extend about 2/3 of the way out in the leading edge of the AS5048. Five inch diameter .060" wall tubing on each side would give you about 8.5 US gallons (32 liters) total. Or just put a 6" tube in the leading edge of each 24" long stub wing and you'd have 5.6 US gallons (21 liters) and never have fuel lines to disconnect. That's another huge volume (and weight of fuel) by itself. But I'm with Sid on the fuel capacity. Not only is bladder size a consideration, the fuel you carry counts against gross weight allocation, whether you fill the tank or not (in the eyes of the FAA). My first fuel tank was a 24 gallon header tank. I came to my senses before I installed it and went with two 8 gallon tanks in the stub wings, although admittedly I did add another 8 gallon tank in the passenger outer wing to run the Airventure Cup race non-stop, so there are extenuating circumstances... Mark Langford ML at N56ML.com website at http://www.N56ML.com --------------------------------------------------------