Weight and Balance tip or trick

[pa19guy]

Hello faithful cubbers,

I have more documentation than you could haul in the plane!!!! Starts back in 1949 to current. I have a PA 18 150 "equal" the logs say so.

Needing help with the weight and balance as I believe my #'s on the ones I have been attempting are not correct.
The weight X Arm equals moment.
Start with an empty plane. 1141# and moment is given on 1993 weight and balance data sheet of 16,380. Add a pilot 235# X 71", passanger 150# X 97", baggage, 50# X 117, and fuel 180# X 74". This equals a great big number. A total moment if you will.

Divide total moment by total weight and subtract out Empty Weight Center of Gravity and compare to your graph? Weight up the vertical and inches along the bottom.

I'm out of CG?

 

[pa19guy]

the 60 extra inches

Problem solved. :lol: :lol:

When empty weight CG is expressed in inches from leading edge and the pilot, passanger, baggage and fuel weight is being multiplied as inches from the Datum there is a 60" discrepancy. That hurts the figures.

Thanks to the Dick at Dans Aircraft. First class help.
I stopped in and Dick interupted his work and BINGO......
Thanks

 

[cubpilot2]

Your aircraft empty weight calculations are incorrect.
The 1141 weight should be multiplied by the empty weight CG measured from the datum. (60 inches ahead of the wing leading edge on PA-18 and averages about 73in.) This would give you a moment of 83293.
Using this and working your numbers you would be at 16.13 CG. (aft of wing leading edge) OK in normal category.