Weight and balance in 3D
Load people, bags and fuel into a see-through airplane and watch the CG move inside (or outside) the envelope.
Try it: add a heavy passenger in the back and fill the baggage area. Watch the CG slide aft and the airplane tip on its balance point. Then burn fuel to see where the CG ends up for landing.
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Example airplane · not for real flight planningHow weight and balance works
- Multiply each weight by its arm (distance from the datum) to get its moment.
- Add up all the weights and all the moments.
- CG = total moment ÷ total weight.
- Check that the weight is at or below maximum gross weight and the CG is inside the envelope, for both takeoff and landing (fuel burn moves the CG).
- Forward CG: more stable, but heavier on the controls, higher stall speed, harder to rotate and flare.
- Aft CG: less stable and lighter on the controls, and stall or spin recovery can become difficult or impossible.
- Use 6 lb per gallon for avgas.
Example airplane only. These numbers are made up for learning and don't come from any real POH. Always use your airplane's actual weight and balance data and loading graphs.
Sources: Weight & Balance Handbook (FAA-H-8083-1B); PHAK Chapter 10.