Moment describes the turning effect of a load around the aircraft datum. In a basic weight and balance calculation it is weight multiplied by arm.
Moment = Weight × Arm
Example
A 170 lb occupant at an arm of 37 in produces 6,290 lb-in of moment. A load with the same weight placed farther aft produces a larger moment.
Total moment and CG
Add the moments of the empty aircraft, occupants, baggage and fuel. Dividing the total moment by total loaded weight gives the loaded CG position.
CG = Total Moment ÷ Total Weight
Moment/1000
Many POH loading tables divide moment by 1,000 simply to keep the printed numbers manageable. The underlying calculation is the same.
Use a model-specific WBcalc calculator to perform the calculation with the loading stations for a supported aircraft.
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WBcalc provides model-specific calculators with aircraft loading stations, fuel data and CG limits. Browse all supported aircraft calculators.
WBcalc is a planning aid. Approved aircraft documents and the current aircraft weight and balance record remain authoritative.