Hey all,

I am setting up my Sig CAP231EX and have come to the point where I am looking at mounting the tank over the CG. If it can be mounted over the CG, would you recommend going that route? If so, should I mount the tank so that the center of the tank is on the CG? I have never mounted a tank this way and don't want to create any nasty flight characteristics. FWIW, I have a Cline, 20 oz DuBro and a Saito 180 for fuel system/power. Any thoughts or suggestions would be greatly appreciated.

Mike

Definitely mount the tank on the CG if you can. Most planes are checked for balance with the fuel tank empty. So, if you keep this additional weight on the balance point, your plane should handle more consistently. I try to cradle the fuel tank in foam and put it right over the CG.

All my planes but one has the tank on the CG. It is the only way to go to ensure that the plane handles the same regardless of the amount of fuel in the plane.

There are very good threads on using a cline in the engine discussion forum. Enjoy !

If the center of the fuel tank is mounted directly over the CG, will the shifting fuel mass cause any problems? Tail heavy on the up lines (less stable) and nose heavy on the down lines (more stable). I would hate to find out that the fuel traveling to the rear of the tank would cause the CG to be too far aft and become unstable, especially on a maiden flight or landings. With the tank mounted directly behind the firewall, it would be nose heavy and gradually aproach the ideal CG. Sorry if I sound a little paranoid, but like I said it is my first time going this route

Thanks,

Mike

On a vertical upline there is no such thing as CG...only gravity
On a vertical downline there is no such thing as CG...only gravity
Compared to the relative weight of the plane, I wouldn't think that fuel slosh would make any noticeable difference.
Besides, we've already had numerous flights on our planes with no ill effects

i run all my planes tank on the CG and the flight stays the same durning the running down of fuel. you will love it. let me know if you need 2 see any pics?