CG limits/envelope for Acrosport 1

Looking for the forward and aft cg limits on the Acrosport 1. Want to do a new weight and balance on the aircraft but could not find in the plans the limits. The old weight and balance worksheet has the main wheel axle at 52 but doesn't say where the 0 line is. Yea I know 52 forward from there but I would like to set the zero line at the base of the prop or just use the 52 line and get the distance for the tailwheel c/l. Then compute CG easily but need the allowable CG range. Using the old locations would be great since it has the fuel locations and other equipment locations.

Thanks

You may want to rething your reasoning. Different engines are slightly different lengths and different propellers are different thicknesses. So you do not want your CG datum to change just because you bought a better propeller.

I will hazard a guess that your airplane's official CG datum is like my Pitts S-2A. The specified datum is located out in front of the airplane and is specified as a certain number of inches in from of the leading edge of the lower wing. Since the lower wing will not change location, you can change the firewall forward stuff and your CG calculations are still valid. Seems strange when you first work CG numbers but it really works quite well. When the factory hung a 6 cylinder engine on the S-2 airframe to make the S-2B, they did not have to change the datum and their CG math could easily compare the two airplane configurations.

Best of luck,

Wes
N78PS