blkstne

My Feedback: (1)

I will be attemping to build a RCM f-86d later this year and am starting to accumulate pieces/parts. Since the plans were made late 60's I would like to update a few things on the plans: separate servos on ailerons, lightened construction with less wood and composites etc. I was considering using a cline fuel regulator and moving the tank to the cg . I read that this would reduce in- flight trimming when the tank empties. I woulds also move more of the electronics forward to make plane easier to balance without adding lead. Here is my question:

1.By placing the tank on the cg the plane's cg will have changed from the original plans because 10-14 onces of fuel is now removed from the forward of the plane. Since the original designer of the plans flew his plane with all that nose weight do I need to balance the plane with a moved cg?

2.If I do need to balance the plane with a new cg How do I determine the amount?

MinnFlyer

My Feedback: (4)

No change in CG

ANY plane should be balanced with an empty tank. When you fill it (In its normal position) you make the plane a little nose-heavy, but most planes can deal with a little extra nose weight.

By moving the tank to the CG, when you fill the tank, you WON'T make the plane a little nose heavy - it will stay right where it's supposed to be.

Insanemoondoggie

I`ve wonder about this also. With the tank at CG , when the plane has a half tank in it and a nose up attitude , wont the fuel run to the back of the tank and make a tail heavy condition ? Or with the nose down , would`nt that make it nose heavy ? Or does it make that much difference ?

MinnFlyer

My Feedback: (4)

It doesn't make that much difference since it's so close to the CG.

You know... It's like when you need to add less weight to the tail than to the nose because the tail is farther away from the CG

blkstne

My Feedback: (1)

thanks for the info.
I feel a little more confident about moving the fuel tank back to the cg now.
I can place the tank close to cg but I will place most of the tank forward the cg mark to give a slight nose heavy for the first flight.

thanks again