I have uploaded a spreadsheet for calculating weight and balance for the Ercoupe. It is in the "files" section of this forum. I would appreciate any comments that you might have about it.
When planning a flight, values are placed in the cells that are colored yellow. In the fuel column, I have put 5 gallons for the nose tank since my Coupe has the steel tank that does not hold the standard 6 gallons. I also show 17 gallons for the wing tanks because the tanks can't be filled to the top because they have a tendancy to vent fuel if they are filled to the top. (In many cases, the tank will continue to dump fuel until you land and open the fuel cap.) Of course, this can be changed if for your situation. I have added conditional formatting so that computed values will turn red if they are out of bounds. This helps identify when an update will push the CG out of bounds. I calculate multiple CG for various fuel loads. It demonstrates how the CG changes as fuel is burn off. I check full fuel, when the wing tanks are empty, when the nose tank is down to the reserve, and finally when you are out of fuel. The last one is academic since we hope that we are not planning on running out of fuel, and CG is probably not your biggest concern when the nose tank runs dry. Something that John Cooper said intrigued me. He said that there is not way get the CG out of bounds if you are within the weight limits. However, I found several situations where the CG is past the aft CG limit when the nose tank fuel begins to get low. Try 170 lbs. for both pilot and passenger and a full load of 65 lbs. for baggage. Maybe I did something wrong in the calculations. Please take a look at a see what you think. Thanks. Frank Nelson N51DV - 415C
